Micro-Sized MoS6@15%Li7P3S11 Composite Enables Stable All-Solid-State Battery with High Capacity

Abstract

All-solid-state lithium batteries without any liquid organic electrolytes can realize high energy density while eliminating flammability issues. Active materials with high specific capacity and favorable interfacial contact within the cathode layer are crucial to the realization of good electrochemical performance. Herein, we report a high-capacity polysulfide cathode material, MoS6@15%Li7P3S11, with a particle size of 1–4 μm. The MoS6 exhibited an impressive initial specific capacity of 913.9 mAh g−1 at 0.1 A g−1. When coupled with the Li7P3S11 electrolyte coating layer, the resultant MoS6@15%Li7P3S11 composite showed improved interfacial contact and an optimized ionic diffusivity range from 10−12–10−11 cm2 s−1 to 10−11–10−10 cm2 s−1. The Li/Li6PS5Cl/MoS6@15%Li7P3S11 all-solid-state lithium battery delivered ultra-high initial and reversible specific capacities of 1083.8 mAh g−1 and 851.5 mAh g−1, respectively, at a current density of 0.1 A g−1 within 1.0–3.0 V. Even under 1 A g−1, the battery maintained a reversible specific capacity of 400 mAh g−1 after 1000 cycles. This work outlines a promising cathode material with intimate interfacial contact and superior ionic transport kinetics within the cathode layer as well as high specific capacity for use in all-solid-state lithium batteries.