Fabrication of RGO@MnS/NC composite electrodes with stable and highrate capability for efficient sodium storage

Abstract

Abatract MnS has drawn growing interest as an anode material for high-performance sodium-ion batteries, owing to its attractive theoretical capacity and favorable redox reversibility during the conversion-type reaction. Nevertheless, substantial volume expansion and sluggish reaction kinetics of MnS upon cycling processes trigger particle pulverization and rapid capacity fading. RGO@MnS/NC composites are fabricated through oxidative polymerization combined with carbothermal reduction–sulfurization. During the synthesis, MnS/NC nanoparticles are in situ immobilized on conductive RGO nanosheets. When employed as an anode material for sodium-ion batteries (SIBs), the rationally engineered RGO@MnS/NC composites exhibit a stable reversible capacity of 140 mAh g − 1 over 1200 long-term cycles under a high current density of 5 A g − 1 . The outstanding cycling stability and rate capability of RGO@MnS/NC originate from its unique structural design. On one hand, MnS nanocrystals immobilized on RGO suppress particle agglomeration, expedite electron/ion transport, and facilitate adequate electrolyte penetration. On the other hand, the outer NC shell creates abundant active sites and further accelerates ion and electron transfer in the electrode. Benefiting from these advantages, RGO@MnS/NC composites hold great potential as a favorable anode material for advanced SIBs.

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