Toward Robust Lithium-Sulfur Batteries Via Advancing Li2S Deposition

Lithium-sulfur batteries (LSBs) with two typical platforms during discharge are prone to the formation of soluble lithium polysulfides (LiPS), leading to a decrease in the cycling life of the battery. Under practical working conditions, the transformation of S-8 into Li2S is cross-executed rather than a stepwise reaction, where the liquid LiPS to solid Li2S conversion can occur at a high state of charge (SOC) to maintain the current requirement. Therefore, advancing Li2S deposition can effectively reduce the accumulation of LiPSs and ultimately improve the reaction kinetics. Herein, a "butterfly material" GeS2-MoS2/rGO is used as a sulfur host. Rich catalytic heterointerfaces can be obtained via the abundant S-S bonds formed between GeS2 and MoS2. MoS2 (left wing) can enhance LiPS adsorption, while the lattice-matching nature of Fdd2 GeS2 (right wing) and Fm (3) over barm Li2S can induce multiple nucleation and regulate the 3D growth of Li2S. Li2S deposition can be advanced to occur at 80% SOC, thereby effectively inhibiting the accumulation of soluble LiPSs. Attributed to the synergistic effect of catalytic and lattice-matching properties, robust coin and pouch LSBs can be achieved.