Lithiophilic Ni3S2 layer decorated nickel foam (Ni3S2@Ni foam) with fast ion transfer kinetics for long-life lithium metal anodes

Lithium metal is regarded as the ultimate choice of anode material for high-energy batteries because of its ultrahigh theoretical capacity and ultralow reduction potential. Unfortunately, the infinite volume change and unavoidable dendrite growth encountered during repeated charge/discharge processes hamper its commercial applications. Herein, a lithiophilic Ni3S2 layer-decorated Ni foam (Ni3S2@Ni foam) is constructed as an advanced three-dimensional (3D) host for long-life lithium metal anodes. Benefiting from the 3D porous structure, the average current density is effectively reduced, and the volume change is accommodated. Remarkably, the Ni3S2@Ni foam with superior lithiophilicity decreases the energy barrier at the initial lithium nucleation stage, and the Li2S-enriched SEI layer formed after the initial activation process facilitates fast ion transfer kinetic, which promotes uniform Li+ surface diffusion and rapid lithium-ion transport, leading to dendrite-free lithium plating/stripping behavior and enhanced cycling performance. As a consequence, the Ni3S2@Ni foam delivers an average Coulombic efficiency (CE) of 98.3 % for 400 cycles at 1 mA cm−2, and a long-term life of over 1300 h with a low voltage hysteresis of ∼25 mV at 2 mA cm−2 is achieved in symmetric cell. Furthermore, full cells matching the LiFePO4 (LFP) cathode realize stable electrochemical performance over 400 cycles at 2C, indicating the application prospects for the Li-Ni3S2@Ni foam anode.