Ordered-Range Tuning of Flash Graphene for Fast-Charging Lithium-Ion Batteries

Abstract

Graphene has yet to be mass produced, so practical fast-charging lithium-ion battery (LIB) prototypes based on graphene are scarce. Graphene suffers from long in-plane and reluctant in-depth lithium diffusion due to its defect-free atomic arrangement, resulting in unsatisfactory rate performance as LIB anodes. In this work, combinatorial flash joule heating and ball milling treatment are implemented to enable gram-scale production of graphene in seconds (known as flash graphene, FG) and in-plane ordered-range modulation of graphene architectures. Following the ball milling, the defect-deficient turbostratic FG is transformed to defect-rich cracked FG (CFG), which has shortened ordered ranges and larger interlayer spacings. The CFG anode outperforms FG, commercial carbon black, and graphite electrodes in terms of specific capacity and rate performance due to open channels and shortened pathways for Li+ transport. Moreover, it shows outstanding cycling stability with a high capacity retention of 99% at the 500th cycle. Furthermore, it works well with the LiFePO4 cathode, enabling fast-charging LIB full battery with a state of charge of 77 and 62% at 2C and 4C, respectively. This research on graphene production and structural engineering provides a practical application for the commercial potential of fast-charging LIBs.