A comprehensive review on energy storage in hybrid electric vehicle

The sharp inclination in the emissions from conventional vehicles contribute to a significant increase in environmental issues, besides the energy crises and low conversion efficiency leads to the evolution of electric vehicles (EV). Hybrid electric vehicles (HEV) have efficient fuel economy and reduce the overall running cost, but the ultimate goal is to shift completely to the pure electric vehicle. Despite this, the main obstruction of HEV is energy storage capability. An EV requires high specific power (W/kg) and high specific energy (W$h/kg) to increase the distance travelled and reduce the time required for charging. The main focus of this paper is on the energy sources as these are the main components in EVs towards making them eco-friendly and cost-effective. Various topologies of EV technology such as HEVs, plug-in HEVs, and many more have been discussed. These topologies of EVs are based on the diverse combination of batteries, fuel cells, super-capacitor, flywheels, regenerative braking systems, which are used as energy sources and energy storage devices. (C) 2021 Periodical Offices of Chang'an University. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd.