Ultrafast transformation of natural graphite into self-supporting graphene as superior anode materials for lithium-ion batteries

Abstract

Graphite possesses remarkable potential as an anode material for lithium-ion batteries, thanks to its superb electrical conductivity and eco-friendliness. Nevertheless, challenging issues persist, such as its low maximum theoretical lithium storage capacity and constraints associated with the regular layered structure, which impede its practical application and advancement. In this regard, we proposed a novel approach to enhance the energy storage performance of lithium-ion batteries, involving the modification of natural graphite through irradiation with a high-current pulsed electron beam (HCPEB). Microscopic observations revealed that during the in-situ transformation of graphite particles into self-supporting graphene nanosheets, the high temperature generated by HCPEB irradiation led to the formation of structural defects, including Stone Wales and double vacancy defects. Consequently, the modified natural graphite electrode (particle size 12 μm) exhibited a reversible capacity of 420.4 mAh/g at 0.2C and maintained 94.5% of its reversible capacity after 500 cycles. In comparison to unmodified graphite (particle size 12 μm), the SEI film displayed enhanced stability, significantly improving cycling performance. These findings demonstrated that the defective graphene nanosheet structure enhances lithium storage activity sites, enlarges layer spacing, and enhances lithium storage performance. This study presents an efficient and environmentally friendly method for producing superior anode materials for lithium-ion batteries.