Electrochemical performance and morphological evolution of hollow Sn microspheres

Using shell-like structures in lithium-ion battery (LIB) can limit the structural degradation/damage induced by the volumetric change during electrochemical cycling. In this work, we synthesize hollow Sn microspheres (Sn-HMSs) via a galvanic replacement reaction, and study the electrochemical performance of the lithium-ion cells with Sn-HMSs as the working electrode. The lithium-ion cells have a charge capacity of 205.9 mA h g⁻¹ after 100 cycles at a current density of 100 mA g⁻¹. In comparison with the charge capacities of 148 mA h g⁻¹ of solid Sn nanospheres and 516.1 mA h g⁻¹ of hollow Sn nanospheres, the results reported in this work reveal the importance of shell-like structures in the retention of the energy storage for LIBs and the size effect on the energy storage. The smaller the hollow Sn spheres, the better is the cycle performance. There are two modes of structural degradation/damage contributing to the capacity loss during electrochemical cycling; one is the disintegration of the Sn-HMSs, and the other is the fracturing of the electrode layer.