Recycled Graphite from Spent Lithium-Ion Batteries as a Conductive Framework Directly Applied in Red Phosphorus-Based Anodes.

The recycling of spent graphite from waste lithium-ion batteries (LIBs) holds great importance in terms of environmental protection and conservation of natural resources. In this study, a simple two-step method involving heat treatment and solution washing was employed to recycle spent graphite. Subsequently, the recycled graphite was milled with red phosphorus to create a carbon/red phosphorus composite that served as an anode material for the new LIBs, aiming to address the low capacity issue. In a half-cell configuration, the carbon/red phosphorus composite exhibited remarkable cycling stability, maintaining a capacity of 721.7 mAh g-1 after 500 cycles at 0.2 A g-1, and demonstrated an excellent rate performance with a capacity of 276.2 mAh g-1 at 3 A g-1. The improved performance can be attributed to the structure of the composite, where the red phosphorus particles are covered by the carbon layer. This composite outperformed pure recycled graphite, highlighting its potential in enhancing the electrochemical properties of LIBs. Furthermore, when the carbon/red phosphorus composite was assembled into a full-cell configuration with LiCoO2 as the cathode material, it displayed a stable electrochemical performance, further validating its practical applicability. This work presents a promising and green strategy for recycling spent graphite and using it in the production of new batteries. The findings offer a high potential for commercialization, contributing to the advancement of sustainable and ecofriendly energy storage technologies.