Multifunctional SnSe–C composite modified 3D scaffolds to regulate lithium nucleation and fast transport for dendrite-free lithium metal anodes

Abstract

Undesirable lithium dendrite growth limits the application of lithium metal anodes in high-energy storage batteries. Here, multifunctional SnSe–C composite modified 3D scaffolds are constructed to achieve dendrite-free lithium deposition. During the initial lithiation stage, the porous SnSe–C composite converts into a Li–Sn alloy and Li₂Se by lithium reduction. The lithiophilic Li–Sn alloy exhibits a low nucleation barrier and realizes homogeneous lithium nucleation. The reductive product Li₂Se with a high ionic conductivity facilitates lithium ion transport, which helps realizing the homogeneous lithium ion flux and reducing concentration polarization. Benefitting from the synergistic effect of the Li–Sn alloy and Li₂Se, the Li/SnSe–C anode exhibits an ultralong lifespan over 1100 h with a low overpotential of 18 mV. In full-cell configurations with LiFePO₄ cathodes, the Li/SnSe–C anode demonstrates enhanced rate capability and cycle stability with a high-capacity retention of 85% over 750 cycles. This work prepares multifunctional SnSe–C composite modified 3D scaffolds to regulate lithium nucleation and transport, which offers new insights and opportunities for developing dendrite-free lithium metal battery technology.