A perspective on the evolution and journey of different types of lithium-ion capacitors: mechanisms, energy-power balance, applicability, and commercialization

Lithium-ion capacitors were conceptualized to bridge the gap between high-energy lithium-ion batteries and high-power electric double-layer capacitors. The history behind the motivation, conceptualization, and development of LICs is studied thoroughly in this article. Since the inception of LICs, various mechanistically different types of lithium-ion capacitors have been assembled, further pushing the energy and power limitations. This perspective provides an outlook on the types of LICs that have evolved based on their construction, assembly, and mechanism. Furthermore, the different charge storage mechanisms involved in the LICs are studied, and how the pre-lithiation strategy affects the mechanism and deliverable energy of the device is analyzed. Further, the effect of the varying charge storage mechanism on the balance of energy-power output is outlined thoroughly with specific emphasis on feasibility and prospects of commercialization. Finally, the road map to commercialization of the LICs and the factors controlling the growth in the energy market space are carefully analyzed.