Li-based all‑carbon dual-ion batteries using graphite recycled from spent Li-ion batteries

Abstract

Recycling and regeneration of spent Li-ion batteries have become an important research topic for a sustainable future. This is predominantly because of the exponentially increasing production & usage of lithium ion batteries (LIBs) leading to an intense reflux as spent/failed/end-of-life batteries in the near future. Research on recycling/regenerating cathode materials has been a major attraction while ignoring the anode part, the graphite. In the present work, we demonstrate the possibility of recycling graphite recovered from spent Li-ion batteries for Li-ion based all‑carbon dual-ion battery (ACDIB) application. Graphite electrodes recovered from failed commercial batteries were thermally treated at different temperatures to optimize their electrochemical activity. Thermally processed graphite was characterized by X-ray diffraction, field-emission scanning electron microscopy, Raman and infrared spectroscopy. The electrochemical performances of both anode and cathode half-cells were optimized and finally all‑carbon dual-ion battery was fabricated and tested with the best performing electrodes. For the anode half-cell, spent graphite thermally processed at 800 °C delivered the highest specific capacity of 250 mAh/g at 372 mA/g and cycling stability over 300 cycles. While for cathode half-cell, the spent graphite processed at 650 °C delivered first discharge capacity of about 65 mAh/g at a specific current of 100 mA/g and reasonable stability for 100 cycles. Coupling these anode and cathode, ACDIB displayed an initial discharge capacity of 58 mAh/g corresponding to an energy density of 255 Wh/kg.