ZIF-8-Templated Hollow Cubelike Si/SiO2@C Nanocomposites for Superior Lithium Storage Performance

Silicon-based anodes are of particular interest for the application of next generation large-capacity lithium-ion batteries (LIBs) because of their natural abundance and ultrahigh theoretical lithium storage ability. However, the huge volume expansion and inferior cyclic stability severely limit their practical applications. To address this challenge, herein, hollow cubelike hybrid composites consisting of a Si/SiO2 cross-link covered by a carbon layer (Si/SiO2@C) have been rationally synthesized through a facile zeolitic imidazolate framework template method. Within hybrid composites, the porous Si/SiO2 cross-link with an internal void can effectively mitigate volume changes and facilitate fast channels for Li+ during the charge–discharge process while the coated carbon layer not only can improve the electrical conductivity of the composites but also guarantees the structural integrity. As expected, the hollow Si/SiO2@C composite electrode has outstanding electrochemical properties including excellent reversible capacity (1280 mAh g–1 at 500 mA g–1 after cycled for 200 times) and superior rate performance (782 and 660 mAh g–1 at current densities of 3.2 and 6.4 A g–1, respectively). Considering the convenient preparation and naturally abundant of composites as well as their excellent electrochemical performance, the hollow Si/SiO2@C may hold great promise as advanced electrodes for next-generation LIBs.