《Sb and O dual doping of Chlorine-rich lithium argyrodite to improve air stability and lithium compatibility for all-solid-state batteries》

The chlorine-rich lithium argyrodite electrolyte with ultra-high ionic conductivity shows great application potential in all-solid-state batteries, while poor wet air and lithium metal compatibility limit its application. Here, by adjusting the Sb and O co-doping agent, Li_5.5P_0.96Sb_0.04S_4.40O_0.10Cl_1.5 electrolyte has a lithium-ion conductivity of up to 7.20 mS cm^-1, excellent air/water and lithium metal compatibility. The improvement of wet air stability is due to the strong Sb-S and P-O bonds in the electrolyte, which inhibits the reaction with water. The improvement of lithium metal stability is attributed to the formation of Li-Sb alloy layer on the anode side, which induces the uniform deposition of lithium ions and promotes the diffusion of lithium ions in the passivation layer (LiCl), and inhibits the growth of lithium dendrites. The lithium symmetric cell using Li_5.5P_0.96Sb_0.04S_4.40O_0.10Cl_1.5 exhibits high critical current density (1.5 mA cm^-2) and ultra-long cycle performance (750 h, 0.1 mA cm^-2). The all-solid-state lithium metal battery using LiNi_0.6Mn_0.2Co_0.2O₂ cathode provides a high initial discharge specific capacity of 144.2 mAh g-1 at 0.1 C. In addition, the assembled battery showed a discharge capacity of 116.2 mAh g-1 at 0.5 C and a capacity retention rate of 83.2 % after 200 cycles. This work provides guidance for the design of sulfide solid electrolytes so that all-solid-state lithium metal batteries have high energy density and long periodicity.

http://https://www.sciencedirect.com/science/article/pii/S0378775323000344