Electrospun Co/Co₃SnC_0.7@N-CNFs as free-standing anode for advanced lithium-ion batteries

Sn is considered as a promising anode for lithium-ion batteries due to its low cost and high theoretical capacity (992 mA h g ⁻¹ with Li_4.4Sn). However, the volume expansion (∼300%) during lithiation/delithiation process can result in the continuous pulverization of active materials and exfoliation from current collector, deteriorating the capacity and cycling performance. Here Co/Co₃SnC_0.7 N-doped carbon nanofibers are successfully synthesized by a feasible electrospinning method. And the materials as the self-standing anode for lithium-ion batteries reveal a high-rate performance as delivering reversible capacities of 480 mA h g⁻¹ at 100 mA g⁻¹ and 290 mA h g⁻¹ at 2000 mA g⁻¹. In addition, the specific capacity can still maintain 320 mA h g⁻¹ at 500 mA g⁻¹ even after 900 cycles, showing the outstanding cycling stability. The inactive metal Co and one-dimensional N-doped carbon nanofibers synergistically promote the electrochemical performance of the Sn-based anode by inhibiting the aggregation of the nanoparticles and buffering volume variation during lithiation/delithiation process.