Uniform distribution of metallic lithium and carbon on the nanoscale for highly stable carbon-based lithium metal anodes

Abstract

Lithium metal anodes (LMAs) present limitations for practical applications due to dendritic Li growth and infinite volume expansion during cycling. Lithium carbon composites exhibit great potential to address these issues owing to the promotion of Li ion diffusion by offering a stable Li host. Herein, we report the fabrication of a carbon-based lithium metal (GKBLi) anode through a ball milling approach by exploiting a mixture of passivated lithium metal powder and graphitic carbon nanomaterials (GKB). The in situ mechanical chemistry lithiation reaction between GKB and Li forms graphite intercalation compounds that exhibit lithiophilicity and generate Li₃N, which effectively promotes the transport of Li ions. The highly uniform distribution of Li and GKB in the anode matrix can enable the deposition and stripping of Li homogeneously. The GKBLi symmetrical cell can stably cycle for more than 1200 h with low voltage hysteresis. Impressively, a full cell assembled with a GKBLi anode and commercial LiFePO₄ cathode achieves extraordinary cycling stability with a capacity retention of 90.9% over 1000 cycles at a high current of 2C. This highly uniform distribution of lithium in the electrodes by a simple dry preparation method provides new insight into high-performance LMAs on an industrial scale.