Locally Ordered Graphitized Carbon Coating Enables Recycled Microsized Silicon as High-Performance Anodes.

Abstract

Microsized silicon (m-Si) emerges as a promising alternative anode material to graphite for lithium-ion batteries, offering high theoretical capacity, cost-effectiveness, and ease of handling. However, the inevitable particle fragmentation resulting from its bulk particle size challenges practical application. Despite the progress in carbon coating techniques that enhance the stability of mi-Si, there is still a demand for high-performance, scalable, and cost-effective m-Si anodes for industrial implementation. Herein, we propose a strategy to unleash the capacity of photovoltaic-waste-derived m-Si particles through locally ordered graphitized carbon coating, contributing to the large-scale production of superior m-Si silicon anodes. The obtained m-Si/carbon material exhibits a high capacity of 3203 mA h g^-1 at 0.2 A g^-1 and a superior rate capability (1532 mA h g^-1 at 4 A g^-1). The NCM811//Si@t-C full cell presents a capacity retention of 95.13% over 100 cycles. The carbon layer composed of locally ordered graphitized domains interconnected with disordered carbon is responsible for the remarkable performance. It effectively buffers the volume changes of m-Si, protects it from electrolyte, and promotes Li⁺ diffusion. Furthermore, this approach, combined with the utilization of m-Si, significantly reduces the overall cost of lithium-ion batteries, opening up opportunities for the application of m-Si.