High-performance all-solid-state Li2S batteries using an interfacial redox mediator

• Published in: Energy & environmental science Vol. 16; no. 2; pp. 610 - 618
• Main Authors: Chun Yuen Kwok, Xu, Shiqi, Kochetkov, Ivan, Zhou, Laidong, Nazar, Linda F
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 16.02.2023
• Subjects: Carrier transport; Cathodes; Current carriers; Electron transfer; Electron transport; Energy storage; Lithium; Lithium sulfur batteries; Lithium-ion batteries; Oxidation; Rechargeable batteries; Retention; Room temperature; Solid electrolytes; Solid state; Transport vehicles
• ISSN: 1754-5692; 1754-5706
• DOI: 10.1039/d2ee03297j

All-solid-state Li–S batteries based on lithium sulfide cathodes have generated much excitement as possible next-generation energy storage candidates because they can offer a high theoretical energy density exceeding that of lithium-ion batteries, and the possibility of “anode-less” cell designs. However, solid-state Li2S cathode kinetics are hindered by both limited ionic and electronic transport and a high activation barrier on charge. Here we report a Li2S/LiVS2 core–shell cathode architecture design, whereby the shell serves as both a charge-carrier transport vehicle and electron transfer mediator for Li2S during oxidation. With an argyrodite-type solid electrolyte, the solid-state Li2S cell exhibits very good rate capability up to 3 mA cm−2 at room temperature, and nearly 80% capacity retention up to 1000 cycles at a moderate current density of 1 mA cm−2. High active material loading (4 and 6 mg cm−2) is demonstrated in this configuration with stable capacity retention. High areal capacity up to 5.3 mA h cm−2 with a very high active material loading of 10 mg cm−2 is also reported, albeit with limited cycle life.