Graphite from Dead Li‐Ion Batteries: A “Powerful” Additive for Fabrication of High‐Performance Li‐Ion Capacitors

Abstract Lithium‐ion capacitors (LICs) are considered a promising next‐generation energy storage system with high energy density and power capability. The conductive additive is a passive and indispensable material in deciding the electrochemical performance of an energy storage device during high current charging and discharging processes. The incorporation of a suitable conductive additive into the layers of an electrode improves electronic conductivity. It reduces the internal resistance and polarization of the electrode resulting in the enhanced performance of the charge‐storage system. Herein, recovered graphite (RG) is reported from dead Li‐ion batteries as an excellent conductive additive that can improve the electronic conductivity of the electrode material. Compared with commercial conductive additive acetylene black (AB), the TiO₂ anode material with 5% RG delivered a high discharge capacity of 163 mAh g⁻¹ at a current rate of 0.15 A g⁻¹ with a coulombic efficiency of ≈99% after 500 cycles in half‐cell assembly. The fabricated AC/TiO₂@5%RG LIC displays an excellent electrochemical performance with a maximum energy density of ≈50 Wh kg⁻¹ at a current density of 0.15 A g⁻¹. Notably, the LIC rendered promising performance at different temperature conditions (0, 10, 25, and 50 °C).