Rational Designing M_xS_y@C (M=Ni, Co, Zn, Cu, Mn) Composites with Controlled Polysuifides Shuttling Behaviors towards Advanced Stable Room Temperature Na-S Batteries

Abstract

Room-temperature sodium-sulfur (RT-Na/S) batteries display attractive potential in large-scale energy-storage, but their practical application was still restricted by the serious dissolution of polysulfides. Herein, supported by the constructing of interface engineering, the metal sulfide-carbon nanocomposite can be prepared with considerable electrochemical properties. Utilizing the double-helix structure of carrageenan-metal hydrogels as precursors, in-situ metal sulfide (M _xS _y) nanostructure/3D carbon aerogels (3D CAs) can be successfully constructed. Importantly, with the assistance of the vulcanization process, 3D carbon architecture was maintained in the composites and acted as a skeleton to optimize their structural stability. As the cathode of RT-Na/S batteries, ZnS/S@C and NiS ₂/S@C delivered an excellent cycling stability and rate performance (179.8 mAh·g ⁻¹ at 20 A·g ⁻¹ after 10000 cycling for ZnS/S@C, 220.3 mAh·g ⁻¹ at 10 A·g ⁻¹ after 3000 cycling for NiS ₂/S@C). The detailed investigation of mechanism revealed that the powerful adsorption for Na ₂S ₄ originated from 3D metal sulfide-carbon structure. The well-designed architecture of sulfide-carbon composites servers as an electrocatalyst to alleviate the shuttle effect of polysulfides, resulting in the long-term electrochemical stability. Given this, the work is expected to provide promising insights for designing advanced cathode materials for RT-Na/S batteries.

Keywords

Room-temperature Na-S battery / High storage capacity / Metal sulfide-carbon nanocomposite / Energy conversion / Molecular electrochemistry / Conductive polymers / Crystal growth / Electrochemistry

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2024 SIOC, CAS, Shanghai, & WILEY-VCH GmbH