A low-cost and advanced SiOx–C composite with hierarchical structure as an anode material for lithium-ion batteries†
A cost-efficient and scalable method is designed to prepare a SiOx–C composite with superior cyclability and excellent rate performance. The glucose addition in a two-step way induces a hierarchical structure, where individual SiOx nanoparticles are wrapped by a conductive carbon layer and these agglomerated particles are further wrapped by a carbon shell functioning as an electrolyte blocking layer. Instrumental analysis indicates that the SiOx domains are comprised of SiO2 and SiO. The SiOx–C anode exhibits a high reversible specific capacity of 674.8 mA h g−1 after 100 cycles at 100 mA g−1 with a capacity retention of about 83.5%. The excellent electrochemical performance is due to the hierarchical structure, the well-dispersed conductive carbon network, and the Li2O and Li4SiO4 generated in the initial discharge process, all of which can immensely relieve the volume expansion induced by the lithiation of silicon. This hierarchical SiOx–C composite has a promising prospect of practical application given its adequate storage capacity, good cycling stability, commercially available materials and simple equipment.