Graphite from Dead Li-Ion Batteries: A "Powerful" Additive for Fabrication of High-Performance Li-Ion Capacitors

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 approximate to 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 approximate to 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 degrees C). The role of graphitic and amorphous carbonaceous materials is explored as potential additives and their application to the Li-ion capacitor, especially for high rates. The graphitic carbon is recovered from the spent Li-ion battery and milled with TiO2 hybrid. image