Electrochemical capacitors for electromobility: A review

Scarcity of resources and emissions increasingly demand sustainable mobility concepts. To compete with conventional vehicles on the market, electromobility requires high-performance rechargeable energy storage systems ideally equipped with high energy and power density, cost-efficiency [1], long lifetimes, extraordinary reliability [2] and safety as well as minimal environmental impact [3]. The last decades have triggered an increasing interest in capacitive energy storage, an electrical storage mechanism found in electrochemical capacitors (ECs), widely called supercapacitors. There are an increasing number of concepts for automobile energy storage systems which make use of this technology [4]. Electrochemical capacitors are already used in markets around the world and have experienced a rapid growth over the past years. This paper provides a general overview of electrochemical capacitors for electromobile applications. It covers their distinctive features, their components, structures and compositions, current and future applications as well as the latest challenges and achievements in research and development.