Preparation of micron-sized silicon monoxide (SiOx)@carbon nanotube (CNT)/polymethyl methacrylate (PMMA) composite capsules as Li-ion battery anodes via a novel pickering emulsion template method

Li-ion batteries (LIBs) with micron-sized silicon monoxide (SiO x ) anodes are promising, ascribed to their favorable cost affordability and remarkable theoretical capacity, while the huge volume expansion and inferior Li + /e − conductivity of SiO x have severely restricted their further development. Herein, a micron-sized SiO x @carbon nanotube (CNT)/polymethyl methacrylate (PMMA) composite capsule is designed for advanced LIB anode via a novel Pickering emulsion template method. The volume variation of SiO x during (de)lithiation reactions is alleviated by the reserved space inside capsules, and the capsule shells of PMMA/CNT engage a significant Li + /e − conductivity as well. Besides, the activity of SiO x greatly remains due to the capsule protection and avoidance of high-temperature treatment. The experimental results indicate that the SiO x @CNT/PMMA composite anodes can present improved lithium storage abilities in aspects of capacity retention, rate performance, and coulombic efficiency. This proposed method hopes to provide a novel micron-scale structure design for Si-based anodes in LIBs.