3D scaffold materials of SnSe | NF | Sn (SSNFS) with various lithium affinities were synthesized by electroplating and selenization processes. The gradient structure of SSNFS was confirmed by multiple characterizations. Density functional theory calculation verifies the difference of lithiophilicity between the lower layer SnSe and the upper layer Sn, which indicates that lithium ions are induced to preferentially nucleate on the lower SnSe layer, facilitating uniform lithium deposition from bottom to top. The half-cell assembled based on the SSNFS gradient framework can stably cycle for 400 times under 1 mA cm −2 and 1 mAh cm −2 , with a low nucleation overpotential of 15 mV and a Coulombic efficiency maintained at 98.86%. The symmetrical cell assembled with this anode demonstrated a long cycle life of 1200 h under the conditions of 1 mA cm −2 and 1 mAh cm −2 , powerfully demonstrating its excellent electrochemical stability. Finally, using LSSNFS as the anode and LiFePO 4 as the cathode, the full cell displays good electrochemical performance as evidenced by its high initial Coulomb efficiency, along with robust cycle stability. The 3D scaffold electrode can enhance its electrochemical property and restrain the formation of lithium dendrites. The reported design of the framework provided a new construction method for a 3D lithiophilic gradient electrode and developed the high-performance lithium metal anode.
Wu et al. (Sat,) studied this question.