Coaxial Electrospinning of CoS1.097@C Core–Shell Fibers Anode Material for High-Performance Sodium-Ion Batteries

Abstract

As an important component that affects the storage performance of sodium-ion batteries (SIBs), novel anode materials still need to be well explored. Herein, CoS1.097@C core–shell fibers as anode material were designed via coaxial electrospinning, stabilization, and carbonization. Specially, CoS1.097 powders are distributed in the inner shell of carbon fibers, and sufficient pore spaces are present among themselves. The unique encapsulation structure, porous characteristics, and one-dimensional conductive carbon shell can enable the CoS1.097@C core–shell fibers’ high initial specific capacity, excellent rate capability, and long cycle life. The initial charge and discharge capacities of the electrode at 50 mA g−1 are 386.0 and 830.9 mAh g−1, respectively. After 2000 cycles at 500 mA g−1, the discharge capacity is 216.3 mAh g−1. Even at 3000 mA g−1, the rate capacity can be maintained at 83.3 mAh g−1.