Regulating the anion disorder and synthesizing the low-cost and high-performance Li6−xPS5−xCl1+x solid electrolytes

Sulfide solid electrolytes have attracted wide attention due to their high ionic conductivity . Li 6 PS 5 Cl is one of the most promising electrolytes for all-solid-state lithium batteries with high-energy-density. It is reported that the disordered arrangement of Cl - in the aragonite structure has a significant effect on the conductivity of Li 6 PS 5 Cl. In this work, the disorder of anion sites is modestly regulated by adjusting the ratio of S and Cl in Li 6−x PS 5−x Cl 1+x electrolyte. In addition, to verify the commonality of this strategy, Li 5.6 PS 4.6 Cl 1.4 is prepared using self-made Li 2 S, and similar results are obtained. On this basis, the density of Li 5.6 PS 4.6 Cl 1.4 electrolyte sheet is improved by hot-pressing, which can successfully inhibit the growth of lithium dendrites . As expected, the ionic conductivity of the sulfide electrolyte and the electrochemical performance of the ASSLBs are greatly improved. A highest ionic conductivity of 8.2 × 10 −3 S cm −1 of Li 5.6 PS 4.6 Cl 1.4 is obtained at room temperature. A high capacity retention of 99.99 % is maintained for NCM811 @Li 2 O//Li 5.6 PS 4.6 Cl 1.4 //Li-In system after 400 cycles at 1 C with ultra-high cathode loading of 35.6 mg cm −2 . Besides, the cost of sulfide electrolytes can be reduced as the decreased usage of Li 2 S. This work proposes a novel synthesis method of low-cost and high-performance Li 6−x PS 5−x Cl 1+x electrolytes.