Enhanced capacity of all-solid-state battery comprising LiNbO3-coated Li(Ni0.8Co0.1Mn0.1)O2 Cathode, Li5.4(PS4)(S0.4Cl1.0Br0.6) solid electrolyte and lithium metal anode

All-solid-state lithium-ion batteries are a promising next-generation technology because they have higher energy densities than their liquid-electrolyte counterparts. Halogen-rich argyrodite, specifically Li 5.4 (PS 4 )(S 0.4 Cl 1.0 Br 0.6 ), was recently shown to have higher ionic conductivities compared with those of other argyrodite-like sulfides. Although the Li 5.4 (PS 4 )(S 0.4 Cl 1.0 Br 0.6 ) in Li | Li 5.4 (PS 4 )(S 0.4 Cl 1.0 Br 0.6 ) | Li(Ni 0.8 Co 0.1 Mn 0.1 )O 2 –Li 5.4 (PS 4 )(S 0.4 Cl 1.0 Br 0.6 ) batteries have shown good electrochemical stability, the low discharge capacity limits the application of the battery. In continuation, this study examined the potential of a carbon additive for altering the electronic conductivity of the cathode and enhancing the capacity of Li | Li 5.4 (PS 4 )(S 0.4 Cl 1.0 Br 0.6 ) | Li(Ni 0.8 Co 0.1 Mn 0.1 )O 2 –Li 5.4 (PS 4 )(S 0.4 Cl 1.0 Br 0.6 ) batteries. After a 50-cycle charge/discharge, the carbon additive (0.1 C) enhanced the discharge capacity from 3.1 to 167 mAh/g, resulted in a capacity retention rate and coulombic efficiency of 95.4% and 99.9% when using 0.1 C and 0.5 C, respectively, and increased the resistance of the battery from 53 to 56 Ω. Therefore, the all-solid-state battery employing high-ion-conductive Li 5.4 (PS 4 )(S 0.4 Cl 1.0 Br 0.6 ) and a carbon-modified cathode showed improved capacity. This study provides a proven framework for developing all-solid-state batteries employing halogen-rich argyrodite (Li 7-α (PS 4 )(S 2-α X α ); α > 1) with enhanced ionic conductivities.