Structurally disordered lithiophilic graphene via solid-state exfoliation enables reversible lithium deposition with fast kinetics

초록

Lithium (Li) metal batteries have attracted significant attention as next-generation energy storage systems due to the high theoretical capacity (3860 mAh g- 1) and low redox potential (-3.04 V vs. SHE) of Li metal. However, their commercialization has been hindered by critical challenges such as low coulombic efficiency and the formation of Li dendrites, which deteriorate cycling stability and safety. Herein, lithiophilic graphene (LG) is prepared via the solid-state exfoliation of graphite under an inert atmosphere, and the atomic defects generated during the exfoliation process are exploited as uniform lithiophilic sites in order to induce dense and homogeneous Li plating. Solid-state exfoliation under inert conditions promotes effective exfoliation due to the absence of oxygen-containing surface groups, which typically inhibit crack propagation, as further validated by molecular dynamics simulations. With the combined effects of lithiophilic defects and controlled particle size in the LG, both Li-Cu and anode-less cells employing LG-modified current collectors exhibit markedly enhanced capacity retention. Moreover, when employed as a coating layer on the separator of an Li-S battery, the LG delivers improved electrochemical performance. These findings highlight the potential of LG to facilitate dendrite-free Li deposition and long-term reversible electrochemical reactions in Li-metal based batteries.

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