Electrochimica Acta, Vol.296, 637-643, 2019
Cryo-treatment in enhancing the electrochemical properties of SnSb/C nanofiber anodes for lithium ion batteries
Aiming at improving the cycling stability of SnSb/C nanofibers prepared by electrospinning followed by carbonization, cryo-treatment was used as a thermal compensation method to adjust the internal stress and obtain different structures. Inspired by cryogenic treatment, we first raised the temperature of cryo-treatment (-50 degrees C, -150 degrees C) and discussed the effect that cryo-treatment temperature on the structure and electrochemical performance. The morphology structure and microstructure of SnSb/C nanofibers were investigated. It was shown that properly cryo-treated temperature could increase the degree of graphitization and effectively offset the internal stress gained from carbonization, which made the metal dispersed more evenly in the nanofibers. Benefiting from the structural advantage, SnSb/C nanofibers obtained at -50 degrees C for 1 h manifested the best capacity retention of 133.1 % for 500 cycles. This work proved temperature is one of the key factors for the production of cryo-treated anodes and -50 degrees C is the most suitable cryo-treatment temperature for the as-derived SnSb/C nanofibers. Carbonization results in volume change and creates internal stress. Properly cryo-treatment can release residual stress and adjust the structure, which can explain the increase of the graphitization. The findings may help to promote the application of cryo-treatment in the field of electrode production. (C) 2018 Elsevier Ltd. All rights reserved.