| Summary: | Sodium ion batteries (SIBs) have been widely studied because of their low cost, low standard redox potential, and abundant sodium availability. However, the structural rupture during the Na+ insertion/extraction processes and the poor conductivity of the anode material limit its cycling stability and rate capability. Herein, SnSe@C was prepared by high-temperature annealing with dopamine hydrochloride as the carbon source, while SnSe was prepared by a protein reduction method. The carbon layer not only works as a protective layer to limit the volume expansion of SnSe and reduce the dissolution of Na2Se and poly-selenides generated during the discharge process in the electrolyte, but also as a conductive matrix to expedite electron transfer, thereby boosting the cycling stability and rate capability of SnSe@C. Benefiting from the above advantages, SnSe@C exhibits a specific capacity of 211.3 mAh g−1 at 0.1 A g−1 after 110 cycles and outstanging rate capability (210.1 mAh g−1 at 5.0 A g−1 and capacity retention rate of 63.2% from 0.1 to 1.0 A g−1). This study not only proposes an idea for promoting the cycling stability and rate capability of SnSe, but also paves the way for providing anodic materials with a stable structure for SIBs.
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