Electrochemically Generated γ‐Li x V 2 O 5 as Insertion Host for High‐Energy Li‐Ion Capacitors

In this study, we explored the feasibility of using electrochemically generated γ‐Li x V 2 O 5 as an insertion‐type anode in the lithium‐ion capacitor (LIC) with activated carbon (AC) as a cathode. Along with the native form of V 2 O 5 , their carbon composites are also used as the electrode material which is prepared by high‐energy ball milling. The electrochemical pre‐lithiation strategy is used to generate the desired γ‐phase of V 2 O 5 (γ‐Li x V 2 O 5 ). Under the optimized mass loading conditions, the LICs are assembled with γ‐Li x V 2 O 5 as anode and AC as a cathode in the organic medium. Among the different LICs fabricated, AC/γ‐Li x V 2 O 5 ‐BM50 configuration delivered an energy density of 33.91 Wh kg −1 @ 0.22 kW kg −1 with excellent capacity retention characteristics. However, a dramatic increase in energy density (43.98 Wh kg −1 @0.28 kW kg −1 ) is noted after the electrolyte modification with fluoroethylene carbonate. The high temperature performance of the assembled LIC is also studied and found that γ‐Li x V 2 O 5 phase can be used as a potential battery‐type component to construct high‐performance hybrid charge storage devices.