In this study, we explore the potential of Vigna Mungo (L) Hepper (black gram skin, BGS), an agricultural byproduct, for synthesising high-quality graphite through a catalytic graphitisation process. Using a nickel-catalysed method, we successfully transformed BGS-derived carbon into highly ordered graphite at 1300 °C (BG-1300), with further surface area enhancement achieved via KOH activation (BG-1300-KOH) including X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and high-resolution transmission electron microscopy (HR-TEM), confirmed the formation of highly ordered graphite with a high degree of graphitisation (62.9 %) and crystallite size (9.69 nm). Electrochemical evaluations demonstrated the potential of BGS-derived graphite as an anode material for lithium-ion batteries (LIBs) and lithium-ion hybrid capacitors (Li-HCs). The BG-1300-KOH sample exhibited a reversible discharge capacity of 610 mAh g−1, outperforming commercial graphite (410 mAh g−1) and pristine BG-1300 (380 mAh g−1). The extent of Na-ion intercalation indicates the degree of disorder in carbon. In this study, as the carbonization temperature increases, the intercalation capacity progressively decreased, reflecting a transition towards more ordered, graphitic carbon. Furthermore, a Li-HC device fabricated with BG-1300-KOH as the anode and nitrogen-phosphorous-doped hard carbon (BGAC-NP) as the cathode achieved a maximum energy density of 175 Wh kg−1 and a power density of 25,000 W kg−1, surpassing many reported carbon-based Li-HC devices. This study highlights the feasibility of converting agricultural waste into high-performance graphite, offering a sustainable pathway for energy storage applications while addressing environmental concerns associated with biomass disposal.

NCM-622 cathodes have been promising cathodes for lithium-ion batteries due to their high reversible specific capacity and low cost. However, the NCM-622 cathode suffers from structural instability, especially at high voltage. Moreover, at elevated voltages and temperatures the cathode suffers from surface side reactions and particle cracks due to the presence of grain boundaries. The in situ doping of Mg2+ is achieved by doping Mg ions during the synthesis procedure using a CSTR and the LiBO2/B2O3 surface coating is achieved by a simple wet-chemistry method; this dual-modification not only protects the surface of the cathode but the Mg2+ ions in the structure also enhance the cycling stability even at high voltage (4.5 V) and temperature (55 °C). As a result, animproved electrochemical behaviour was observed and the cathode could retain 82.5% of its initial capacity after 100 cycles at 4.5 V. Furthermore, the presence of the hybrid coating on the surface protects the cathode from HF attack and reduces the voltage polarisation during high temperature and voltage cycling. Such a dual-modification strategy can be commercially viable and useful for modification of high-energy-density NCM-622 cathodes.

The integration of high nickel rich single crystal LiNi0.8Co0.1Mn0.1O2 (SCNCM811) with argyrodite sulfide solid electrolyte (Li6PS5Cl) is crucial for realizing the high-energy density all-solid-state lithium batteries (ASSLBs). However, the development of ASSLBs is hindered by complex issues including unstable cathode-electrolyte interface, detrimental side reactions between high nickel oxide cathodes and argyrodite sulfide solid electrolytes (SSEs). Further oxygen release from cathode surface at higher working voltages during continuous charge/discharge cycles leads to severe cracking of cathodes and undesirable decomposition of SSEs which aggravate the interfacial impedance to lithium-ions. These phenomena contribute to interfacial instability constraints resulting in progressive degradation of electrochemical performance of ASSLBs. Herein, a simple and facile modification approach was employed for the surface modification of SCNCM811 using boric acid (H3BO3) as boron source followed by dry annealing process to facilitate boron surface modification. The proposed coating strategy significantly enhanced the interfacial stability of high performance all-solid-state lithium batteries by constructing a stable interface for smooth lithium-ion diffusion and reduced the degradative side reactions with sulfide solid electrolytes. On these grounds, the modified B-SCNCM811/LPSCl/Li-In all-solid-state lithium batteries exhibited impressive cycling stability with capacity retention of 88.2 % over the course of 50 cycles at 0.5C. Diverse and comprehensive characterizations, combined with galvanostatic intermittent titration technique, electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and X-ray photoelectron spectroscopy (XPS) further provided insights for solving the interfacial problems and improved chemical and electrochemical characteristics of ASSLBs.

Electric vehicle (EV) charging has recently become one of the most pressing issues. Given the growing demand for lithium-ion batteries (LIBs) in electric vehicles, this study analyzes optimization methods for improving existing approaches to speed up charging while reducing temperature rise. This work formulates a double-objective function for battery charging based on an electrothermal model. The focused objective function is comprised of a combination of two different fitness functions. Optimization of charging current is made dynamically following a battery's temperature. These experimental findings validate the proposed charging strategy's effectiveness in delivering the optimal current profile. This approach demonstrably achieves a well-calibrated balance between competing performance objectives. By adopting the suggested strategy, any increase in the battery's temperature can be maintained within an acceptable temperature range. The proposed constant current constant voltage (CCCV) charging method takes a total charging time of 1874 s, with a temperature shift from 26 to 45.78 (Formula presented.).

The potential of two-dimensional (2D) transition metal dichalcogenides (TMDs), especially molybdenum telluride (MoTe2), in sophisticated electrical and low-energy neuromorphic applications, has attracted a lot of interest. The creation, characteristics, and uses of MoTe2-based memristive devices are summarized in this review paper, with an emphasis on their potential as artificial synapses for neuromorphic computing. We thoroughly examine the special properties of MoTe2, such as its remarkable resistance switching response, excellent linearity in synaptic potentiation, and customizable phase states. These characteristics make it possible to implement basic computational functions with minimal energy consumption, including decimal arithmetic operations and the commutative principles of addition and multiplication. In addition to simulating intricate synaptic processes such as long-term potentiation (LTP), long-term depression (LTD), and spike-timing-dependent plasticity (STDP), the article emphasizes the experimental performances of MoTe2 memristors, which include their capacity to execute exact decimal arithmetic operations. The demonstration of centimeter-scale 2D MoTe2 film-based memristor arrays attaining over 90% recognition accuracy in handwritten digit identification tests further demonstrates the devices’ great scalability, stability, and incorporation capabilities. Notwithstanding these developments, issues such as poor environmental robustness, phase transition sensitivity, and low thermal stability still exist. The creation of hybrid or composite materials, doping, and structural alteration are some of the methods to get beyond these obstacles that are covered in the paper. The need for scalable, economical synthesis techniques and a better comprehension of the material's mechanical, optical, and electrical properties through modeling and experiments are emphasized.

In this work, we demonstrate the stable resistive switching (RS) and interesting neuromorphic features of Ag/Ni-HfO₂/P⁺⁺-Si memristors. This unique technique stacks a Ni-HfO₂ resistive switching (RS) layer on top of a P⁺⁺-Si layer, considerably improving the stability, switching efficiency, and synaptic characteristics of memristors. A detailed physical model describes the RS filamentary process, which involves Ag+ ions migrating and forming electrical filaments with applied voltage, shifting the memristor consistent response from low-resistance and high-resistance phases. The memristor maintains consistent RS properties for 96 h with low deterioration, because of the strong Ni-HfO₂ layer that improves switching stability. The memristor chip performs successfully in both voltage sweeping and pulse mode processes. The pulse-mode endurance results show that the low-resistance state (LRS) and high-resistance state (HRS) are stable after 100 cycles, with SET and RESET reaction times of 960 and 1636 ms, correspondingly. These findings show the memristors capacity for quick, energy-efficient switching. Furthermore, the memristor shows synaptic action, which resembles biological activities for example short-term (STP) and long-term plasticity (LTP). The conductivity regulation, like neurotransmitter release and synaptic weight correction, is accomplished by ion migration during voltage pulses. Also, the paired-pulse facilitation (PPF) reveals the memristors capacity to simulate synaptic activities, with a PPF index of 130 %. The variations in pulse height and width indicate the progressive change from STP to LTP. Thus, the new device design indicates potential in neuromorphic computing, combining robust resistive switching with sophisticated synaptic properties to simulate essential brain activities such as memory retention and adaptation. These findings indicate that Ag/Ni-HfO₂/P⁺⁺-Si memristors have potential consistent switching efficiency and synaptic abilities serve as promising contenders for future artificial intelligence and computer hardware applications.

LiFePO4 (LFP) is widely used as cathode material in Li-ion batteries in electric vehicles (EV’s). The theoretical capacity of LFP is 170 mAhg−1. It is difficult to achieve the theoretical capacity value, especially at high C-rates, mainly because of its poor ionic as well as electronic conductivity. Several doping strategies have been adopted of which Mn as well as V doping individually, show beneficial effect in improving the electrochemical performance. However, co-doping of these two ions and the synergistic effect, if any, on the electrochemical performance of LFP has not been explored hitherto. In the present study, Mn and V co-doped LFP cathode materials were synthesized by solvothermal method. Phase formation was confirmed by X-ray diffraction studies, while 7Li MAS NMR spectra revealed changes in isomeric shift (-18.03 ppm for pristine LFP, -1.01 ppm for Mn-doped, and -0.65 ppm for Mn, V co-doped LFP), confirming Mn and V are incorporated into the olivine lattice. The co-doped LFP exhibited a unique two-dimensional morphology with uniform, fluffy particles (~ 3 µm × 2 µm). X-ray photoelectron spectra confirmed the presence of Fe2+, Mn2+, and V4+ oxidation states. The Li-ion diffusion coefficient (DLi+) of Mn and V co-doped LFP (6.93 × 10−15 cm2s−1) was higher than that of pristine LFP (2.97 × 10−15 cm2s−1), indicating enhanced Li-ion diffusion in the co-doped sample. Electrochemical tests in half-cell mode showed that co-doped LFP achieved a 167, 153 and 145 mAhg−1 capacity at 0.1, 1.0, and 2.0 C-rates, respectively. Inaddition, the co-doped composition showed excellent capacity retention, even at high C-rates i.e., 135 mAhg−1 with 90% retention after 500 cycles at 1C and 101.3 mAhg-1 with 70% retention after 1000 cycles at 2C. Also, the co-doped phase exhibited lower polarization and charge transfer resistance, highlighting its potential for high-performance lithium-ion batteries.

Due to the increasing demand for water, it has become critical to find an innovative solution to supply clean water. Nanomaterials are widely being used for environmental remediation, and, herein, we report a one-step solution by synthesizing a silver-coated magnetic iron oxide (Ag-MIO) nanoparticle-infused hydrogel. Magnetic iron oxide nanomaterials synthesized by the chemical method were characterized using scanning electron microscopy (SEM), powder X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy. The XRD spectrum elucidated the predominant formation of the hematite phase, and EDX mapping confirmed the formation of Ag-MIO. This novel Ag-MIO-infused hydrogel showed promising potential for sustainable environmental remediation via efficient heavy metal reduction and methylene blue degradation (95%). This hydrogel has also shown potential biological efficacy against pathogenic microorganisms like Escherichia coli.

The increasing demand for high-performance lithium-ion batteries (LIBs) in electric vehicles (EVs) and renewable energy storage systems underscores the need for advanced cathode materials with enhanced energy density, thermal stability, and long-term cycling performance. Nickel-rich cathodes, such as NCM-622, offer high capacity and energy density but suffer from structural degradation, transition metal dissolution, and electrolyte decomposition at elevated voltages and temperatures. In this study, magnesium-doped single-crystalline (SC) NCM-622 cathode material is synthesised using a multi-step annealing process to address these challenges. The Mg2+ doping significantly improves structural stability by suppressing cation mixing, stabilizing the layered structure, and mitigating abrupt lattice distortions. The SC morphology eliminates grain boundary-induced failures, enhancing electrochemical performance and thermal stability. Electrochemical analyses reveal that the Mg-doped SC NCM-622 cathode exhibits superior cyclic stability, retaining 81.7 % of its capacity after 300 cycles at 4.3 V and maintaining performance even at elevated temperatures. This study highlights the effectiveness of Mg2+ doping and SC architecture in addressing the limitations of Ni-rich cathodes, offering a promising approach for developing high-energy-density LIBs for next-generation energy applications.

Dual-modified Zr4+-doped and ZrO2-coated NCM-622 with excellent electrochemical properties was synthesized by simple wet-chemical coating. X-ray diffraction analysis revealed the unit cell expansion along the c-direction in the Zr-modified sample, which was substantial in improving the lithium-ion kinetics. The surface coating of ZrO2 was visible in TEM images protecting the cathode from surface-side reactions. The electrochemical performance of the Zr-modified sample was superior to that of the other modified and uncoated samples; it showed higher cyclic stability even after 100 cycles at a 1C rate and offers 86.3% capacity retention, whereas the unmodified sample yielded only 21.7% of its initial capacity. Zr4+ doping acts as a pillar, stabilizing the structure to provide better Li+ diffusion and increased cyclability and rate capability. Further analysis showed that the Zr-modification has shown superior electrochemical performance and cyclic stability even at elevated temperatures of 55 °C. The ZrO2 coating on the surface can act as an HF scavenger during cycling at high temperatures. The superior cycling stability and rate capability can be attributed to the synergetic effect of simultaneous doping and coating of zirconia on the NCM-622. Graphical abstract: [Figure not available: see fulltext.].

All-solid-state lithium-ion batteries (ASSLBs) offer superior performance and enhanced safety compared to the existing liquid-based lithium-ion batteries (LIBs). However, recently, an issue has emerged in ASSLBs in which carbon materials accelerate the deterioration of the sulfide solid electrolytes (SSEs), thereby reducing electrochemical performance. In this paper, we present approach for carbon materials that can enhance compatibility with solid electrolytes in ASSLBs. The compatibility between carbon and solid electrolyte is improved by removing amorphous carbon on the carbon surface, which unavoidably forms on the surface during carbon material synthesis, covering about 5∼7 nm on the highly crystalline graphite surface. The evaluation of ASSLBs revealed significant differences in electrochemical performance depending on pristine graphite (P-Gr), which had amorphous carbon adsorbed on the surface, and surface-crystallized graphite (SC-Gr) where amorphous carbon was removed. Interestingly, there was no significant difference in electrochemical performance observed in LIBs. The improved electrochemical properties were closely associated with the quantity of Li2S, Li- phosphide, and SEI layer formed by the decomposition of the solid electrolyte during charging and discharging, subsequently affecting interfacial resistance between graphite and SSEs. In addition, stable electrochemical performance was achieved in both half-cell and full-cell evaluations due to the suppressed degradation of the solid electrolyte and the stable interface. This was observed despite reducing the proportion of the solid electrolyte within the anode composite from 40 % to 20 %. We anticipate that improving the interface compatibility between crystalline carbon and the solid electrolyte will broaden the applications of carbon materials in solid-state electrolytes, advancing the development of ASSLBs that meet specific electrochemical performance criteria.

Surface properties of nanomaterials are directly related to their electrochemical performance, with surfactants playing an essential role in their cost-effective synthesis as structure-directing agents and templates. This research article discusses the effects of neutral, cationic, and anionic surfactants on the capacitance of bimetallic ZnCo2O4 nanomaterial, synthesized via a straightforward hydrothermal-annealing method. We investigated how cationic (cetyl-trimethyl ammonium bromide), anionic (sodium dodecyl sulphate), and non-ionic (urea) surfactants influence the electrochemical characteristics of ZnCo2O4 nano-powders. All three surfactant-based ZnCo2O4 electrodes exhibited Faradaic behaviour during electrochemical tests. The ionic nature of the surfactants significantly impacted the charge-storage mechanism, with specific capacitance values rising in the order of Urea (550 Fg−1) < C-TAB (740 Fg−1) < SDS (980 Fg−1) at a 1 Ag−1 in half-cell studies. The ZnCo2O4-SDS displayed the highest surface redox reactivity and superior electrochemical performance, with 426 Fg−1 in full-cell studies, energy density of 230 WhKg−1 (1 Ag−1), power density of 18,213.9 WKg−1 (10 Ag−1), and 93 % capacitance retention is observed over 50,000 cycles (50 Ag−1).

As the demand for high-capacity Ni-rich lithium-ion batteries continues to grow, the push to increase their energy density at the material level also increases. To achieve higher energy densities, binder material (BM) and carbon additive (CA) ratios must be minimized, resulting in careful consideration of their selection. Recently, carbon nanotubes (CNTs) have been popularized; however, unwanted migration of CNTs during electrode manufacturing causes severe carbon additive agglomeration on the surface, leaving behind a poor conductive network throughout the electrode. This is particularly emphasized, as the binder concentration is lowered to maximize cell energy density. One of the possible solutions is to establish a robust electrically conductive network by incorporating a trace amount of high-aspect-ratio carbon nanofibers (CNFs) alongside CNTs as the CA in Ni-rich active material (AM) cathode electrodes. The results indicate that adding an optimized amount of 0.25 wt % CNFs with 0.75 wt % CNTs constructs an effective conductive network and reduces the through-plane (from the electrode surface to the current collector) resistance significantly. With an electrode ratio of 98:1:1 (AM/CA/BM), the performance is outstanding and shows a capacity retention of 93.7% after 100 cycles at 1C. It is also observed that CNFs help in developing a good electrical network in high-energy-density thick electrodes, as the cycling performance of dual conductive additive CNF/CNT mix electrodes achieves a capacity retention of 97.01% at a loading level of ∼20 mg cm-2. Therefore, the addition of CNFs as a trace with CNTs proved beneficial to bypass through-plane parallel resistances within the electrode caused by undesirable migration of CNTs during electrode synthesis. Hence, providing sufficient electrical highways from the electrode surface to the current collector through addition of trace CNFs can significantly enhance the electrochemical performance of the cells and become a facile and retrofittable solution to high electrical resistances arising in the current electrode production process.

Interfacial solar steam generation is considered as economical and more effective implementation of Solar steam generation (SSG) where solar energy is concentrated at the liquid surface via the utilization of heat localization materials (HLM). Herein we report the fabrication of an HLM constituted of a nanocomposite absorber of graphitic carbon nitride (g-C3N4) and covellite copper sulfide (CuS) supported on a mixed cellulose ester membrane, with a substrate of air laid paper-wrapped polystyrene foam. This structure allowed for strong broad-spectrum absorbance, increased hydrophilic character and minimal thermal losses. The HLM system absorbed 98% of the material and had an evaporation rate of 2.58 kgs per square meter per hour. This is twice the evaporation rate of water tested under the same conditions. Moreover, as fabricated HLM was also incorporated in a solar still in order to assess its practical performance in solar distillation. Initial studies proved that HLM modified solar still was more effective than conventional solar stills.

Emerging novel 2D materials with unique electrochemical properties generate massive interest among researchers to fabricate the supercapacitors with high energy density without fading actual power density. In present work, a novel 2D Bismuthene-Molybdenum disulfide composite (Biene-MoS2 NC) was synthesized which serves as an effective active material for the fabrication of electrodes for supercapacitors with superior electrochemical characteristics. The synthesized Biene-MoS2 NC electrode provides the improved specific capacity of 195.9 mAh/g at the sweep rate of 10 mV/s together with the total stored capacity, outer surface adsorption capacity, and intercalation capacity of 285, 10.8, and 274.2 mAh/g respectively and their percentage of capacitance and diffusion of 36.3 % and 63.7 % respectively. The pouch type supercapacitor cell was fabricated using Biene-MoS2 NC as positive electrode (cathode) and activated carbon (AC) as negative electrode (anode) which demonstrated high areal capacitance of 38.2 mF/cm2 at the current density of 0.5 mA/cm2 and also it delivered the enhanced areal energy and power densities of 11.94 μWh/cm2 and 1 mW/cm2 respectively.

Biomass-derived activated carbon materials have been attracted as low-cost and sustainable electrode materials for energy storage applications. In this work, we synthesised activated carbon from black gram whole skin for the first time, and the used source is a cost-effective carbon precursor. Nitrogen and phosphorous doping in activated carbon improved electronic conductivity, surface area and porosity. In supercapacitor application, the nitrogen and phosphorous doped activated carbon sample showed a high specific capacitance of 425 F g−1 at 0.5 A g−1 and cycling stability of about 92.5 % capacitance retention even after 5000 cycles in a three-electrode system. The observed stable specific capacitance in a three-electrode system encouraged us to make a two-electrode symmetric device, showing a specific capacitance of 100 F g−1 at 0.5 A g−1 with a higher energy density of 20 Wh kg−1. In addition, the lithium storage capability of doped carbon showed good capacity of 750 mAh g−1 at 0.1 A g−1 with a reversible capacity of 687 mAh g−1 after 100 cycles. The hetero-atom doped activated carbon derived from black gram skin showed outstanding electrochemical performance towards supercapacitor and lithium battery application, indicating a potential alternative to fossil fuel-derived carbon.

Ni-rich cathodes are very attractive in terms of high-energy density cathodes. However, it still suffers from various disadvantages, making commercialization more difficult. A dual-modifying cathode is a simple and efficient strategy that can have a synergistic effect of surface coating on the outside, and doping can have internal structure stabilization. CSTR-level doping of Mg2+ can significantly extend the battery’s cycle life due to its pillar effect, and LiNbO3 is a prominent coating material with high ionic conductivity. The dual-modified cathode in this study has shown excellent electrochemical performance in terms of cyclic stability and rate performance, even at 4.5 V vs. Li. The modified cathode showed 85.4% capacity retention at 4.3 V and 87.11% at 4.5 V, whereas the bare showed only 78.9% and 68.2%, respectively. The LiNbO3-coating protects the material from the surface side reactions from the electrolytes at high voltage operations, and the “pillar effect” due to Mg2+ doping stabilizes the structure for longer cycles and higher C-rates, making this dually modified cathode a prominent cathode material for lithium-ion batteries. Graphical abstract: (Figure presented.)

Ever growth in the energy demand has catapulted us to explore various energies. Henceforth, to meet these ends, among the different cathode active materials, nickel (Ni) rich polycrystalline (PC) cathode materials have been known to serve the purpose aptly. Yet, these PC Ni-rich cathode materials have yielded inferior performances with an increase in voltage and temperature. The absence of grain boundaries in the intrinsic structure, high mechanical strength, high thermal stability, and controllable crystal faucet have made SC cathodes a better prospect. Yet, there are challenges to overcome in the SC cathodes, like larger crystals hindering the Li+ transport, which leads to disappointing electrochemical performance. Through this perspective article, we wish to elucidate the crucial factors that facilitate the growth of SC-NCM cathode, viable dopants, and coating materials that could enhance the performance, future scope, and scalability of SC-NCM at the Industrial level.

Fatty acids are highly preferred as phase change materials (PCMs) for thermal energy storage. However, low thermal conductivity limits their thermal performance and so reduces their direct applicability in latent heat storage systems. In present work PCM nanocomposites with 0.25% to 1.25% of graphene in lauric acid have been prepared and characterized. The highest thermal conductivity of sample with 1% mass fraction of graphene was found to be enhanced by 45.2% and 50.1% during melting and cooling, respectively compared to pristine PCM. This enhanced heating/cooling rates and thermal conductivity are attributed to the optimized impregnation of graphene into lauric acid.

Herein, we report the Li-ion conducting composite material, Li0.57La0.29TiO3 (LLTO), coated on a microporous polyethylene separator to use in rechargeable Lithium-metal batteries. Since the LLTO contains structural Li-ions and the three-dimensional conducting channels within, it not only improved the ionic conductivity of coated separator but also improved the surface electrolyte wettability and suppressed the dendrite formation. As a result, the Lithium-metal battery cycling stability and safety features are increased. Consequently, the ceramic composite separator enabled a specific capacity of 105.6 mAhg−1 for Li/LiMn2O4 coin cell, and 80 % capacity retention is observed even after 500 cycles at 1C, indicating its promising practical potential application. This work provides a feasible and efficient modification strategy of separators for improving the cycling performance and safety of Lithium-metal batteries. In addition, the ceramic composite-coated separator could instill confidence in using Lithium metal as the attractive anode for high-capacity Li-air and Li‑sulfur batteries with enhanced thermal and cyclic stability.

Pigeon excreta (PE) contains a significant amount of organic components, which are harmful to the environment and humans. Hence, the proper disposal of PE deals with practical problems. Furthermore, using PE for other energy sources is an efficient innovation. In this study, an innovative technique was implemented for producing agglomeration free and distinct metal oxides using PE as a surfactant and capping agent. The different characterizations and their analysis explain the mechanism involved in forming distinct metal oxide nanosheets utilizing PE. The obtained samples were confirmed by the characteristic peaks of PE mediated metal oxides such as (NiO, Co3O4 and CuO) observed in X-ray diffraction (43.47°, 36.61° and 35.71°), and the UV-DRS band-gap narrowing (2.4, 2.13 and 2.02 eV). In the FTIR spectrum, it is clearly evident that there is a high amine group in the PE which plays a key role in reducing the agglomeration in the metal oxides. The morphology of PE mediated NiO, Co3O4 and CuO revealed nanoflakes and nanosheets like structures identified from FE-SEM analysis. The photovoltaic performance of the PE mediated metal oxides showed improved photocurrent conversion efficiencies of 1.2–1.6 times more than pure metal oxides. Among all, the CuO-PE had the most significant photovoltaic performance, with a photoconversion efficiency of 3.22 %. The reduction of I3− to 3I− along the counter electrode/electrolyte interaction is facilitated by the PE mediated transition metal oxides, as shown by the photocurrent response, Tafel plot and electrical impedance spectroscopy results, which were discussed in detail.

Controlling the electronic devices through the Internet of Things (IoT) interfaces is essential in our mundane life. By observing the important parameters, controlling of the system can be performed which produces important pieces of information by keeping in mind the functioning of these e-devices. The outcomes of the environmental observances are associated with this scrutiny. The collected information can be used to create actions such as heating of devices, dominant cooling, or long-term statistic. Through the help of network or any other android application, data can be uploaded on the cloud. In the present study, Arduino UNO and Wi-Fi modules are used to process and transfer the sensed data to the Thingspeak cloud. Thus, the cloud platform (Thing speak) contains the parameters that are received. Any variation in the surroundings is reported in the form of a database through the cloud computing method.

Herein, we present an advanced approach for the estimation of battery model parameters using the Cuckoo Search optimization Algorithm (CSA) for Lithium-Ion Batteries (LIB) in Electric Vehicle (EV) applications. In any battery-powered system, accurate determination of internal battery parameters and, as a consequence, SOC prediction is essential. The precision of parameter identification, which is mostly governed by battery model parameters, will significantly impact the battery’s safety, characteristics, and performance. Hence, we need effective, simple, and efficient parameter estimation algorithms to estimate the parameters accurately. The parameters of the NMC cell are predicted using a 2RC (second-order RC) Equivalent Circuit Model (ECM). The experimental data was utilized to determine the parameters and the correlation between OCV and SOC. The suggested approach and validation results demonstrate that the CSA for detecting parameters in LIBs is efficient and resilient. The proposed algorithm tends to limit the root mean square error of 0.44 percent between experimental and simulation results. Simulated results show that the novel approach outperforms the standard algorithm nonlinear least square method and other metaheuristic methods such as GA and PSO.

The recent surge of research in the development of sodium-ion batteries (SIBs) as an alternative to the lithium-ion batteries (LIBs) has shown that the SIBs can reduce the load of the LIBs in certain areas. However, the development of SIBs in the commercial arenas is yet to be tapped. This perspective delineates the importance of Ni-rich cathodes and various strategies to ameliorate the performance of the Ni-rich cathodes in the SIBs. Also, discussed various synthesis routes for the industrial-scale synthesis of Ni-rich materials and tried to elucidate the importance of SC cathodes and the necessity to develop those in SIBs.

Accurate estimation of battery internal model parameters and consequently SOC prediction is crucial in any battery power systems. Hence, it is a fundamental need in electric vehicles, smart grids, and energy storage systems. The accuracy of parameters identification will affect the battery management system, battery safety, characteristics, and performance which mainly depends on battery model parameters. So, to estimate the parameters accurately and easily, we require effective, simple, and robust parameters estimation algorithms. In this article, we propose a new method for estimation of parameters using least square method algorithm for Lithium-Ion Batteries (LIBs) for Electric Vehicle (EV) applications. In this, Second-order RC equivalent circuit model is considered for estimation of parameters of NMC battery. The estimation of parameters and relation between OCV-SOC nonlinear is obtained from the experimental data. This proposed method shows that the calculation of parameters is fast and efficient.

A comprehensive understanding of lithium-ion batteries became an essential aspect of solid-state electrochemical research due to their coalescence with routine. While it exhilarates us with increase in productivity of LIBs due to the emergence of Ni-rich cathode materials, the scope to upscale it according to the industrial needs is yet to be tapped to its full potential. Through this perspective article, the functional differences between LIBs and SIBs, state-of-the-art Single-crystalline NCM cathode, the status of the respective research works, crucial factors for industry scaling of the cathode materials, and the future scope of the research work are elucidated.

In this study, flower-like MoS2 nanospheres were synthesized via a facile hydrothermal route. The morphological and phase analysis confirmed the formation of polycrystalline MoS2 nanoflowers assembled by lamellar nanosheets. A novel shape-stabilized phase change material was fabricated by imprisoning different concentrations of MoS2 into myristic acid. It was observed from the experimental results that the duration of melting and cooling rates for PCM of 0.25 wt%, 0.5 wt%, 0.75 wt%, 1 wt%, 1.25 wt% increased as compared to pristine counterparts. 1 wt% had the highest heat transfer rate, with a value of 9.4% and 52.81% for melting and cooling, respectively. The result from analytical technique showed there was no chemical reaction between MoS2 and myristic acid even after multiple cycles. Since this unique MoS2 based composite has indicated good thermal reliability for latent-heat storage, and release, this composite can be considered as an appropriate PCM for thermal energy storage applications.

Phase change materials (PCM) are commonly utilized materials in latent heat energy storage systems. In the present study, Fe2O3 was incorporated into the eutectic mixture of myristic acid and lauric acid. The composites were prepared by a melting and mixing method. Fourier transform infrared spectroscopy and dynamic light scattering results revealed the physicochemical properties of the eutectic mixture. Thermal analysis was performed on the optimized PCM mixtures with various Fe2O3 loadings of 1 wt.%, 2 wt.%, 3 wt.%, 4 wt.%, and 5 wt.%. It is observed from the experimental results that the duration of melting and cooling rates for PCM composite with 4 wt.% Fe2O3 loadings was significantly improved, i.e., 85.72% and 78.31%, respectively, when compared to its pristine counterparts. These enhanced heating/cooling rates and thermal conductivity are attributed to the optimized impregnation of 4 wt.% Fe2O3 nanostructures into the eutectic mixture.

The objective of this article is to illustrate the various fast charging techniques that are being used to charge the lithium-ion batteries in electric vehicles. Various charging protocols such as constant current, constant voltage, constant current constant voltage, multistage constant current, varying current method, pulse charging methods are critically reviewed and explained in their broader perspective of fundamental concepts to their modeling/simulation. Amongst, the constant current constant voltage charging approach is considered as a benchmark for other charging protocols in terms of the charging time, the charging efficiency, and battery life. A critical comparison among the various charging methods mentioned above are discussed and possible future research directions in the design and development of new fast charging techniques have been proposed based on the commercial and societal demands.

Phase change materials (PCM) are commonly utilized materials in the latent heat energy storage systems. However, they have the limitation of low thermal conductivities which leads to poor charging and discharging rates. Lauric acid dispersed with the iron oxide nanoparticle was tested for its thermal performance to characterize its phase change properties. Different compositions of lauric acid were formulated with varying concentrations of iron oxide ranging from 1 wt. % to 4 wt. % were investigated. From the thermal charging and discharging studies, it was observed that lauric acid with 4% had shown the maximum heat transfer rate. Also, the FTIR spectrum confirmed the chemical stability and uniform dispersion of nanoparticle in lauric acid even after several thermal cycles. Such, lauric acid nanocomposites embedded with the iron oxide could be potential candidates in PCM applications.

Nickel-rich materials, as a front-running cathode for lithium-ion batteries suffer from inherent degradation issues such as inter/intragranular cracks and phase transition under the high-current density condition. Although vigorous efforts have mitigated these current issues, the practical applications are not successfully achieved due to the material instability and complex synthesis process. Herein, a structurally stable, macrovoid-containing, nickel-rich material is developed using an affordable, scalable, and one-pot coprecipitation method without using surfactants/etching agents/complex-ion forming agents. The strategically developed macrovoid-induced cathode via a self-organization process exhibits excellent full-cell rate capability, cycle life at discharge rate of 5 C, and structural stability even at the industrial electrode conditions, owing to the fast Li-ion diffusion, the internal macrovoid acting as “buffer zones” for stress relief, and highly stable nanostructure around the void during cycling. This strategy for nickel-rich cathodes can be viable for industries in the preparation of high-performance lithium-ion cells.

Green-synthesized mesoporous-structures have widespread attention due to its environmentally-benign nature and numerous applications. Herein, we report the green synthesis of mesoporous iron oxide network using green tea extract. The morphological and phase analyses were evaluated and elucidated the formation of mesoporous-structure showing predominantly hematite-phase. Catalytic role of α-Fe2O3 was investigated in Fenton reaction for the removal of methylene blue dye to understand its significance in wastewater treatment.

Cathode material degradation during cycling is one of the key obstacles to upgrading lithium-ion and beyond-lithium-ion batteries for high-energy and varied-temperature applications. Herein, we highlight recent progress in material surface-coating as the foremost solution to resist the surface phase-transitions and cracking in cathode particles in mono-valent (Li, Na, K) and multi-valent (Mg, Ca, Al) ion batteries under high-voltage and varied-temperature conditions. Importantly, we shed light on the future of materials surface-coating technology with possible research directions. In this regard, we provide our viewpoint on a novel hybrid surface-coating strategy, which has been successfully evaluated in LiCoO2-based-Li-ion cells under adverse conditions with industrial specifications for customer-demanding applications. The proposed coating strategy includes a first surface-coating of the as-prepared cathode powders (by sol–gel) and then an ultra-thin ceramic-oxide coating on their electrodes (by atomic-layer deposition). What makes it appealing for industry applications is that such a coating strategy can effectively maintain the integrity of materials under electro-mechanical stress, at the cathode particle and electrode- levels. Furthermore, it leads to improved energy-density and voltage retention at 4.55 V and 45 °C with highly loaded electrodes (≈24 mg.cm−2). Finally, the development of this coating technology for beyond-lithium-ion batteries could be a major research challenge, but one that is viable.

Battery industries and research groups are further investigating LiCoO2 to unravel the capacity at high-voltages (>4.3 vs Li). The research trends are towards the surface modification of the LiCoO2 and stabilize it structurally and chemically. In this report, the recent progress in the surface-coating materials i.e., single-element, binary, and ternary hybrid-materials etc. and their coating methods are illustrated. Further, the importance of evaluating the surface-coated LiCoO2 in the Li-ion full-cell is highlighted with our recent results. Mg,P-coated LiCoO2 full-cells exhibit excellent thermal stability, high-temperature cycle and room-temperature rate capabilities with high energy-density of ≈1.4 W h cc−1 at 10 C and 4.35 V. Besides, pouch-type full-cells with high-loading (18 mg cm−2) electrodes of layered-Li(Ni,Mn)O2 -coated LiCoO2 not only deliver prolonged cycle-life at room and elevated-temperatures but also high energy-density of ≈2 W h cc−1 after 100 cycles at 25 °C and 4.47 V (vs natural graphite). The post-mortem analyses and experimental results suggest enhanced electrochemical performances are attributed to the mechanistic behaviour of hybrid surface-coating layers that can mitigate undesirable side reactions and micro-crack formations on the surface of LiCoO2 at the adverse conditions. Hence, the surface-engineering of electrode materials could be a viable path to achieve the high-energy Li-ion cells for future applications.

Developing nano/micro-structures which can effectively upgrade the intriguing properties of electrode materials for energy storage devices is always a key research topic. Ultrathin nanosheets were proved to be one of the potential nanostructures due to their high specific surface area, good active contact areas and porous channels. Herein, we report a unique hierarchical micro-spherical morphology of well-stacked and completely miscible molybdenum disulfide (MoS2) nanosheets and graphene sheets, were successfully synthesized via a simple and industrial scale spray-drying technique to take the advantages of both MoS2 and graphene in terms of their high practical capacity values and high electronic conductivity, respectively. Computational studies were performed to understand the interfacial behaviour of MoS 2 and graphene, which proves high stability of the composite with high interfacial binding energy (-2.02 eV) among them. Further, the lithium and sodium storage properties have been tested and reveal excellent cyclic stability over 250 and 500 cycles, respectively, with the highest initial capacity values of 1300 mAh g-1 and 640 mAh g-1 at 0.1 A g-1.

Carbon nanofibers (CNF) have been synthesized under partial combustion conditions in a flame reactor using different mixtures of hydrocarbon gases in the presence and absence of precursors. The hydrogen (H2) adsorption studies have been carried out using a high pressure Sievert's apparatus maintained at a constant temperature (24° C). The flame synthesized CNFs showed high degree of H2 adsorption capacities at 100 atm pressure. The highest H2 capacities recorded have been 4.1 wt% [for CNF produced by liquefied petroleum gas (LPG)-Air (E-17)], 3.7 wt% [for nano carbons produced by Methane-Acetylene-Air (EMAC-4)] and 5.04 wt% for [Lithium intercalated sample (Li-EMAC-4)] respectively.

Potency of the cathode material is an important feature for upgrading lithium-ion/sodium-ion battery technology for next-generation applications such as in electrical grids and advanced electric vehicles. Various limitations related to electrochemical and socio-economic issues of these batteries are current research challenges. Amongst the various possible solutions to address such issues, developing nanostructured cathode materials, such as one-dimensional nanostructures, by versatile and easily scaled-up processes could be one of the options. Consequently, in the present study, Li1+x(Mn1/3Ni1/3Fe1/3)O2 one-dimensional nanofibers have been fabricated via a simple and low-cost electrospinning technique and used as a cathode material in lithium-ion batteries, which showed an improved initial reversible capacity (∼109 mA h g-1) and cyclic stability at the 0.1 C rate when compared to the performance of Li1+x(Mn1/3Ni1/3Fe1/3)O2 nanoparticles. On the other hand, the feasibility of this low-cost and eco-friendly material was also tested in sodium-ion batteries, and the same trend is observed. The enhanced electrochemical and structural features in both systems could be ascribed to the exceptional features of one-dimensional nanofibers such as efficient electron transport, facile strain relaxation, and short Li+/Na+ diffusion pathways. This journal is

Sodium-ion batteries are the next-generation in battery technology; however, their commercial development is hampered by electrode performance. The P2-type Na2/3(Fe1/2Mn1/2)O2 with a hexagonal structure and P63/mmc space group is considered a candidate sodium-ion battery cathode material due to its high capacity (∼190 mAh·g-1) and energy density (∼520 mWh·g-1), which are comparable to those of the commercial LiFePO4 and LiMn2O4 lithium-ion battery cathodes, with previously unexplained poor cycling performance being the major barrier to its commercial application. We use operando synchrotron X-ray powder diffraction to understand the origins of the capacity fade of the Na2/3(Fe1/2Mn1/2)O2 material during cycling over the relatively wide 1.5-4.2 V (vs Na) window. We found a complex phase-evolution, involving transitions from P63/mmc (P2-type at the open-circuit voltage) to P63 (OP4-type when fully charged) to P63/mmc (P2-type at 3.4-2.0 V) to Cmcm (P2-type at 2.0-1.5 V) symmetry structures during the desodiation and sodiation of the Na2/3(Fe1/2Mn1/2)O2 cathode. The associated large cell-volume changes with the multiple two-phase reactions are likely to be responsible for the poor cycling performance, clearly suggesting a 2.0-4.0 V window of operation as a strategy to improve cycling performance. We demonstrated here that the P2-type Na2/3(Fe1/2Mn1/2)O2 cathode is able to deliver ∼25% better cycling performance with the strategic operation window. This significant improvement in cycling performance implies that by characterizing the phase evolution and reaction mechanisms during battery function we are able to propose these modifications to the conditions of battery use that improve performance, highlighting the importance of the interplay between structure and electrochemistry.

A peculiar architecture of one-dimensional MnO<inf>2</inf> nanowires was synthesized by an optimized hydrothermal route and has been lucratively exploited to fabricate highly efficient microporous electrode overlays for lithium batteries. These fabricated electrodes comprised of interconnected nanoscale units with wire-shaped profile which exhibits high aspect ratio in the order of 10². Their outstanding intercalation/de-intercalation prerogatives have also been studied to fabricate lithium coin cells which revealed a significant specific capacity and power density of 251 mAh g^-1 and 200 W kg^-1, respectively. A detailed electrochemical study was performed to elucidate how surface morphology and redox reaction behaviors underlying these electrodes influence the cyclic behavior of the electrode. Rate capability tests at different C-rates were performed to evaluate the capacity and cycling performance of these coin cells.

The development of cathode materials with high capacity and cycle stability is essential to emerging electric-vehicle technologies, however, of serious environmental concern is that materials with these properties developed so far contain the toxic and expensive Co. We report here the Li-rich, Co-free Li1+xMO2 (M = Li, Ni, Mn, Fe) composite cathode material, prepared via a template-free, one-step wet-chemical method followed by conventional annealing in an oxygen atmosphere. The cathode has an unprecedented level of cation mixing, where the electrochemically-active component contains four elements at the transition-metal (3a) site and 20% Ni at the active Li site (3b). We find Ni2+/Ni3+/Ni4+ to be the active redox-center of the cathode with lithiation/delithiation occurring via a solid-solution reaction where the lattice responds approximately linearly with cycling, differing to that observed for iso-structural commercial cathodes with a lower level of cation mixing. The composite cathode has ∼75% active material and delivers an initial discharge-capacity of ∼103 mA h g-1 with a reasonable capacity retention of ∼84.4% after 100 cycles. Notably, the electrochemically-active component possesses a capacity of ∼139 mA h g-1, approaching that of the commercialized LiCoO2 and Li(Ni1/3Mn1/3Co1/3)O2 materials. Importantly, our operando neutron powder-diffraction results suggest excellent structural stability of this active component, which exhibits ∼80% less change in its stacking-axis than for LiCoO2 with approximately the same capacity, a characteristic that may be exploited to enhance significantly the capacity retention of this and similar materials. © the Owner Societies.

Sodium-ion batteries can be the best alternative to lithium-ion batteries, because of their similar electrochemistry, nontoxicity, and elemental abundance and the low cost of sodium. They still stand in need of better cathodes in terms of their structural and electrochemical aspects. Accordingly, the present study reports the first example of the preparation of Na2/3(Fe 1/2Mn1/2)O2 hierarchical nanofibers by electrospinning. The nanofibers with aggregated nanocrystallites along the fiber direction have been characterized structurally and electrochemically, resulting in enhanced cyclability when compared to nanoparticles, with initial discharge capacity of ∼195 mAh g-1. This is attributed to the good interconnection among the fibers, with well-guided charge transfers and better electrolyte contacts. © 2014 American Chemical Society.

The superior performance of lithium metal oxide cathode materials is a key aspect for the advanced development of lithium-ion battery (LIB) technology in portable electronics and high-end applications such as renewable energy units, electric vehicles (EVs) and hybrid electric vehicles (HEVs) etc. However, this battery technology suffers from some critical problems related to electrochemical performance, storage efficiency, safety and cost. Tremendous research is performed globally to solve these problems associated with battery performance. One of the potential ways to improve battery electrochemical performance and safety is by developing hybrid lithium metal oxide based one-dimensional (1D) nanostructures by simple and advanced electrospinning processes. These electrospun nanostructures of continuous fibrous morphology are attractive as new cathode materials due to their shorter Li ion diffusion pathways, high surface area and porous network. Since lithium-ion battery technology growth is tremendous and grabbing the attention of the world-wide scientific community, an update on recent progress in such fields is required. In this review, we discuss an in-depth summary about the significant role of electrospun lithium metal oxide based cathode materials in improving ionic conductivity, electrochemical stability, rate capability and safety; as well as possible future research challenges and prospects. In addition, we briefly describe the very recent progress of electrospun materials in anode and separator/electrolyte applications of LIBs. © 2013 The Royal Society of Chemistry.

Polyaniline is known for its good thermal stability, high electrical conductivity and corrosion resistance. Incorporating fillers like carbon black as secondary phases enhances these properties, making it available for electrical and electronics applications. Introducing these composites as nanofibers on an electrode overlay can be beneficial from electron mobility standpoint. Electrospinning is one of the commonly pursued methods for synthesizing nanofibers. However, it is difficult to electrospin polyaniline alone as it is insoluble in organic/inorganic solvents. Inorder to overcome this problem, polyaniline is blended with binder solutions like polyvinyl alcohol (PVA). But, the presence of an insulating carrier like PVA introduces a percolation threshold (threshold voltage beyond which a material starts behaving as a conductor) which can affect applications where high conductivity is required. The problem adds up when carbon black is introduced into the polyaniline matrix. Carbon black tends to create a solid gel when mixed with PVA resulting in a high viscosity solution which makes this blend not suitable for electrospinning. In the present chapter, highly conductive porous (~70%) polyaniline-carbon black composite nanofiber mats were fabricated via electrospinning. The fiber mat was electrospun using polyvinyl alcohol as carrier solution which was later decomposed at ~230 °C to get a complete conducting nanofiber network and did not result in any structural collapse. This heat treatment reduced the fiber diameter from ~240 nm to ~170 nm, increased surface pore size from 0.4±0.08 μm to 1.3±0.35 μm and the porosity of the mat increased from 40±1.2% to 75±2%. The removal of the carrier phase in the composite was confirmed by Fourier transform infrared spectroscopy. The spatial specific conductance measurements using scanning electrochemical microscopy showed that the presence of polyvinyl alcohol could introduce percolation threshold and removal of the same by heat treatment substantially reduced the percolation threshold and increased the fiber mat conductance. The heat-treated fibers showed four times increase in specific conductance values on removal of carrier phase from the fiber structure. The present chapter discusses the role of carbon black in polyaniline matrix, which can be beneficial as conductive electrode applications in electronic and photovoltaic storage devices. © 2013 by Nova Science Publishers, Inc. All rights reserved.

Nanowires of NiO were successfully synthesized using a simple hydrothermal route. The nanowires were characterized for phase composition and morphology by X-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques, respectively. XRD analysis showed that the powders produced were of high purity cubic NiO phase. Selected area electron diffraction (SAED) analysis during TEM showed the growth direction of NiO nanowires in (100), while exhibiting an average diameter of ∼ 65nm. BET analysis showed these nanowires exhibiting a surface area of 153.2m2/g. These nanowires were electrophoretically deposited on titanium foils as thin layer (∼5μm thickness) and were studied for their capacitive behavior as electrodes for supercapacitor applications. Image analysis and atomic force microscopy (AFM) studies revealed the thin film coating to be highly porous (>50%). Cyclic voltammetry (CV) studies on these electrodes exhibited a specific mass capacitance of 750F/g with 12% capacitance fade at the end of 1000 cycles. The present study elucidates how NiO surface morphology and OH- adsorption/desorption behaviors underlying these electrodes impact the chemical and structural stability performance. © 2013 Elsevier B.V.

The present study reports the electrospinning of TiO2-graphene composite nanofibers to develop conductive nano-fiber mats using polyvinylpyrrolidone as a carrier solution. This carrier solution was sublimated at 450 °C to attain a complete conducting continuous nanofibrous network. It was observed during the annealing that as the graphene content was increased to 1 wt% the continuous fiber morphology was lost. Annealing did not have any impact on the fiber diameter (∼150 nm) or morphology as the graphene content was maintained between 0.0-0.7 wt%. The surface porosity of these samples was found be in the range of 45-48%. The presence of graphene in TiO2 nanofibers was confirmed using Raman spectroscopy. Photoluminescence spectroscopy showed excitonic intensity to be lower in graphene-TiO2 samples indicating that the recombination of photo-induced electrons and holes in TiO2 can be effectively inhibited in the composite nanofibers. Fluorescence spectroscopy was used to confirm this phenomenon where blue and quenched emissions were observed for the electrospun TiO2 nanofibers and composite fibers, respectively. Conductivity measurements showed the mean specific conductance values obtained for TiO2-graphene composites to be about two times higher values than that of the electrospun TiO2 fibers. Assembling these TiO2-graphene fiber composites as photoanodes in dye sensitized solar cells, an efficiency of 7.6% was attained. © 2012 The Royal Society of Chemistry.

The present study reports the electrospinning of commercially available polyaniline-carbon black composite to develop conductive nanofibrous mats using polyvinyl alcohol as a binder solution. This binder solution was sublimated at 230 °C to attain a complete conducting nanofiber network. The binder sublimation was confirmed using thermo gravimetric analysis (TGA). Ultra-violet visible spectroscopy was used to determine the refractive index values for porosity measurements. It was observed that the heat treatment reduced the fiber diameter from ~250 nm to ~160 nm and increased the porosity from 41±1.2% to 70±2%. The spatial specific conductance mapping using Scanning Electro-Chemical Microscopy showed that the presence of polyvinyl alcohol binder in polyaniline-carbon black composite could introduce percolation threshold. The heat-treated fibers showed four times increase in specific conductance values on removal of binder phase from the fiber structure. The role of nanoscaled Schottky barriers in determining conductive pathways through polymer by hopping mechanism and also along carbon black particles are also been proposed in this study. © 2012 by American Scientific Publishers.

The present study demonstrates an original approach by which Au nanoparticles (∼10 nm) are embedded into TiO2 fibers via electrospinning. The photocatalytic performance of the resultant fibrous material was studied and related to the architecture and the nature of the internal interfaces in the composite. It was found that embedment of nano Au particles into the TiO2 fiber significantly improved the photocatalytic performance as compared to non-embedded ones. Electrospun fibers with the Au nanoparticles (∼10 nm) showed an average fiber diameter of ∼380 nm. The photocatalytic studies of Au embedded TiO2 fibers using ultra-violet (UV) visible spectroscopy showed ∼35% increase in photocatalytic activity when compared to the TiO2 fibers without the Au nanoparticles after 7 hrs of UV irradiation. This increase in photocatalysis was attributed to the ability of Au to increase charge separation in TiO 2 and also to the ability of Au to transfer plasmonic energy to the dye. Copyright © 2012 American Scientific Publishers. All rights reserved.

The present study demonstrates a novel approach by which titanium foils coated with electropolymerized poly(3,4-ethylenedioxythiophene) (PEDOT) in combination with sputtered platinum can be processed into a high-surface area cathodes for dye-sensitized solar cells (DSSCs). A detailed study has been performed to elucidate how surface nanomorphology and I-/I3- redox reaction behaviors underlying these photocathodes impact the DSSC performances. From the analysis of the relevant electrochemical parameters, an intrinsic correlation between the photovoltaic performances and the cathode surface area has been deduced for such a system and explained on the basis of relative contributions of the galvanic coupling properties of the nanomorphology PEDOT film and platinum. Depending on the type of photocathodes incorporated, it was observed that these PEDOT coated cathodes can exhibit higher stability over a given time range and photo-conversion efficiencies 12-40%, higher than that achievable in absence of the intermediate PEDOT coatings. It has been shown that DSSCs based on such metal-polymer hybrid photo-cathodes allow significant room for improvement in the catalytic performance at the electrode/electrolyte interface. Copyright © 2012 American Scientific Publishers.