Performance enhancement of Sn-Ti-C nanofibers anode for lithium-ion batteries via deep cryogenic treatment

Abstract

Obtaining a high specific capacity of Sn-Ti composite anode for lithium-ion batteries while maintaining stable cycle is a key issue to be solved. Research on using reasonable compensation treatment is of importance for solving the problem. In this work, the Sn-Ti-C nanofibers are prepared by electrospinning and using deep cryogenic treatment as supplementary treatment and then carbonization. After the deep cryogenic treatment, the abundant grain boundaries are introduced into Sn particles, which more easily combine with Ti to form Sn-Ti particles in the process of high-temperature carbonization. The Sn-Ti particles inside and outside the grooved nanofibers with low Ti content inhibits the volume expansion of Sn during the cycles and maintains the high specific capacity for Sn alloy. For the sample as the anode, the capacity can remain at 557 mAh g−1 and the capacity retention of 98.7% over 100 cycles. The improvement of electrochemical performance can be simply implemented by deep cryogenic treatment, which provides reliable theoretical and practical data for the preparation of Sn-Ti composite anode for lithium-ion batteries.