Back-Integration of Recovered Graphite from Waste-Batteries as Ultra-High Capacity and Stable Anode for Potassium-Ion Battery

The rapid growth of lithium-ion batteries (LIBs) in many markets from portable electronics to large scale electric vehicles makes it increasingly urgent to address recycling of strategic materials from used batteries. Herein, we report the excellent electrochemical performance of recycled graphite (REG) from spent LIBs, which was successfully employed as an anode in potassium-ion batteries (KIBs). The graphite-anode not only delivers highly reversible capacity of 361.4 mAh g(-1) (at 0.1 C) but also demonstrates good long-term cycling stability. The phase evolution of electrochemically potassium intercalated/deintercalated REG electrodes is elucidated using in-situ X-ray diffraction. The well-preserved structure of the recycled graphite makes it ideal host for reversible intercalation and de-intercalation of K-ions. Furthermore, a potassium-hybrid capacitor was fabricated by coupling the recycled graphite with textile waste-derived activated carbon as cathode material. The cell demonstrates considerable energy density of 84.5 Wh kg(-1) and power density of 400 W kg(-1), respectively. Apart from the great electrochemical performances, the low-cost, abundant, and sustainable recycled graphite in this work will help to address the challenges in Li-ion battery recycling and show the prospects of next-generation battery system development.