Electrochemically Generated γ-Li V O as Insertion Host for High-Energy Li-Ion Capacitors.

In this study, we explored the feasibility of using electrochemically generated γ-Li V O 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 O , 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 O (γ-Li V O ). Under the optimized mass loading conditions, the LICs are assembled with γ-Li V O as anode and AC as a cathode in the organic medium. Among the different LICs fabricated, AC/γ-Li V O -BM50 configuration delivered an energy density of 33.91 Wh kg @ 0.22 kW kg with excellent capacity retention characteristics. However, a dramatic increase in energy density (43.98 Wh kg @0.28 kW kg ) 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 V O phase can be used as a potential battery-type component to construct high-performance hybrid charge storage devices.