Space-Confined Synthesis of Ultrasmall SnO<sub>2</sub> Nanodots within Ordered Mesoporous Carbon CMK-3 for High-Performance Lithium Ion Batteries
Yanni Li, Lei Zhu, Tianhao Yao, Ting Liu, Ruifeng Qian, Fang Li, Xiaogang Han, Lingmin Yu, Hongkang Wang
Abstract
SnO2 suffers from the severe pulverization problem when used as an anode material for lithium ion batteries (LIBs). To overcome its drawbacks, hybridizing nanosized SnO2 with carbon-based materials is very impactful, and we herein successfully synthesize ultrasmall SnO2 nanodots (average size of around 5 nm) within the channels of the commercial ordered mesoporous carbon (CMK-3), in which the tin precursor is prefilled under a vacuum and then is easily converted into SnO2 by annealing at 350 °C in air. The as-prepared SnO2@CMK-3 composite demonstrates good lithium storage properties, displaying a discharge capacity of 898.8 mA h/g at the 150th cycle at 500 mA/g, apparently higher than that for the bare SnO2 and CMK-3 electrodes. The superior electrochemical performance of SnO2@CMK-3 can be due to the high conductivity and vast pore volume of the CMK-3 carbon matrices, which efficiently alleviate the volume change induced pulverization and enhance the electrode conductivity. Besides, the uniform distribution of the ultrasmall SnO2 nanodots within CMK-3 maximally enlarges the lithium storage sites and minimizes the effect of the volume variation.