Graphite-Nanoplate-Coated Bi2S3 Composite with High-Volume Energy Density and Excellent Cycle Life for Room-Temperature Sodium-Sulfide Batteries.

Graphite-nanoplate-coated Bi₂S₃ composite (Bi₂S₃@C) has been prepared by a simple, scalable, and energy-efficient precipitation method combined with ball milling. The Bi₂S₃@C composite was used as the cathode material for sodium-sulfide batteries. It delivered an initial capacity of 550 mAh g⁻¹ and high stable specific energy in the range of 275-300 Wh kg⁻¹ at 0.1 C, with an enhanced capacity retention of 69 % over 100 cycles. The unique structure demonstrates superior cycling stability, with a capacity drop of 0.3 % per cycle over 100 cycles, compared with that of bare Bi₂S₃. The sodium storage mechanism of Bi₂S₃ was investigated based on ex situ X-ray diffraction and scanning transmission electron microscopy. [ABSTRACT FROM AUTHOR]