Impact of CO2 activation on the structure, composition, and performance of Sb/C nanohybrid lithium/sodium-ion battery anodes

Antimony (Sb) has been regarded as one of the most promising anode materials for both lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) and attracted much attention in recent years. How to alleviate the volumetric effect of antimony during change and discharge processes is the key point to promote Sb-based anodes to practical applications. Carbon dioxide (CO2) activation is applied to improve rate performance of the Sb/C nanohybrid anodes caused by limited diffusion of Li/Na ions in excessive carbon component Based on the reaction between CO2 and carbon, CO2 activation can not only reduce the excess carbon content of the Sb/C nanohybrid but also create abundant mesopores inside of the carbon matrix, leading to an enhanced rate performance. Additionally, CO2 activation is also a fast and facile method which can perfectly adapt to the fabrication system. As a result, after CO2 activation, the average capacity of the Sb/C nanohybrid LIB anodes is increased by about 18 times (from 9 mAh g−1 to 160 mAh g−1) at a current density of 3300 mA g−1. Moreover, the application of the CO2-activated Sb/C nanohybrid as sodium-ion battery anode is also demonstrated, showing a good electrochemical performance.