High-Energy All-Solid-State Lithium Batteries with Ultralong Cycle Life

High energy and power densities are the greatest challenge for all-solid-state lithium batteries due to the poor interfacial compatibility between electrodes and electrolytes as well as low lithium ion transfer kinetics in solid materials. Intimate contact at the cathode–solid electrolyte interface and high ionic conductivity of solid electrolyte are crucial to realizing high-performance all-solid-state lithium batteries. Here, we report a general interfacial architecture, i.e., Li7P3S11 electrolyte particles anchored on cobalt sulfide nanosheets, by an in situ liquid-phase approach. The anchored Li7P3S11 electrolyte particle size is around 10 nm, which is the smallest sulfide electrolyte particles reported to date, leading to an increased contact area and intimate contact interface between electrolyte and active materials. The neat Li7P3S11 electrolyte synthesized by the same liquid-phase approach exhibits a very high ionic conductivity of 1.5 × 10–3 S cm–1 with a particle size of 0.4–1.0 μm. All-solid-state lithium batteries employing cobalt sulfide–Li7P3S11 nanocomposites in combination with the neat Li7P3S11 electrolyte and Super P as the cathode and lithium metal as the anode exhibit excellent rate capability and cycling stability, showing reversible discharge capacity of 421 mAh g–1 at 1.27 mA cm–2 after 1000 cycles. Moreover, the obtained all-solid-state lithium batteries possesses very high energy and power densities, exhibiting 360 Wh kg–1 and 3823 W kg–1 at current densities of 0.13 and 12.73 mA cm–2, respectively. This contribution demonstrates a new interfacial design for all-solid-state battery with high performance.