In electric vehicles (EVs), the integration of multiple energy storages (MES) is preferred to be a practical solution for improving the performance and lifetime of battery under dynamic driving conditions. At present, most of the commercialized EVs utilize battery as single energy storage to meet the desired driving range. Extended travel range beyond 500 km requires a higher battery capacity with prolonged charging time, which increases the EV production cost. However, this trend is expected to change in the future by integration of MES, particularly a combination like battery + ultracapacitor, fuel cell + battery, fuel cell + ultracapacitor and fuel cell + battery + ultracapacitor. To understand the working mechanism of MES, a technical review on features, benefits and operational characteristics of different energy storages for EVs is discussed. The current framework of the chapter is to provide a preliminary conceptualization on the integration of MES and in-depth technical information on various configurations of multiport DC-DC converter for EV powertrain. In addition, to provide insightful information on MES in EV application, a new flexible bidirectional multiport converter is discussed and its performance results are verified through simulation. Furthermore, current challenges in market adoption and next-generation design considerations of multiport converters in the context of future research prospects are indicated.