Selective catalysis remedies polysulfide shuttling in lithium-sulfur batteries

Abstract The shuttling of soluble lithium polysulfides between the electrodes leads to serious capacity fading and excess use of electrolyte, which severely bottlenecks practical use of Li-S batteries. Here selective catalysis is proposed as a fundamental remedy for the consecutive solid-liquid-solid sulfur redox reactions. The proof-of-concept In 2 O 3 catalyst targetedly slows down the solid-liquid conversion, dissolution of elemental sulfur to polysulfides, while accelerates the liquid-solid conversion, deposition of polysulfides into insoluble Li 2 S, which basically reduces accumulation of polysulfides in electrolyte, finally inhibiting the shuttle effect. The selective catalysis is revealed, experimentally and theoretically, by changes of activation energies and kinetic currents, modified reaction pathway together with the probed LiInS 2 intermediates, and gradual deactivation of the catalyst. The In 2 O 3 -catalysed Li-S battery works steadily over 1000 cycles at 4.0 C and yields an initial areal capacity up to 9.4 mAh cm −2 with a sulfur loading of ~9.0 mg cm −2 .