A feasible recycling route for spent graphite: Microwave-assisted puffing with Fe2O3 loading to construct high-performance anode for lithium-ion batteries

Abstract

Nowadays, one of the important issues associating with the lithium-ion battery industry is to address the inefficient utilization of spent graphite from plenty of spent batteries. Conventional methods including discarding or burning will exacerbate the environmental risks, which calls for novel routes to optimize the recycling of spent graphite. This study proposes a novel recycling strategy for spent graphite to construct Fe2O3@microwave-puffed graphite (Fe2O3@MPG) composite anode for high-capacity lithium storage. By means of mild intercalation followed by microwave treatment, spent graphite is converted to puffed graphite which can be used as framework for loading Fe2O3 to form Fe2O3@MPG with sandwich structure. This sandwich structure can provide conductive networks and channels to enhance conductivity and Li ions transfer, as well as confine Fe2O3 in microwave-puffed graphite framework to ease the structural instability caused by the volume change of Fe2O3, thereby endowing the Fe2O3@MPG composite with superior rate performance, high capacity, and excellent structural stability. The Fe2O3@MPG electrode possesses a specific capacity of 1100 mAh g−1 at 200 mA g−1, exhibits excellent rate performance with a capacity of 632 mAh g−1 at 2000 mA g−1, and delivers an outstanding cycling performance for 500 cycles. This study not only provides an important method for the efficient recycling of spent graphite but develops a universal method for modifying transition metal oxides anode utilizing spent graphite, thereby promoting the closed-loop lifecycle of graphite and the resource sustainability in the LIBs industry.