Low-temperature fabrication of porous SiO with carbon shell for high-stability lithium ion battery

Porous silicon monoxide (p-SiO) is one of the most promising anode materials for lithium-ion batteries because it possesses high theoretical capacity and small volume expansion. Traditionally, SiO is prepared at 1200 °C, which restrains the application of SiO materials due to its high consumption of energy. Herein, a low-temperature synthesis process of p-SiO at 650 °C is developed from a controllable magnesiothermic reduction of porous silica . Compared with normally reduced solid silica (SiO 2 @SiO), p-SiO is fabricated more easily from porous SiO 2 due to the improved contact between SiO 2 and Mg atom. Moreover, high porosity of p-SiO facilitates the growth of carbon shell, making p-SiO@C with remarkable electrochemical properties . The reversible capacity for p-SiO@C (839.6 mA h g −1 , at 500 mA g −1 ) is about two times that for SiO 2 @SiO@C (426.4 mA h g −1 , at 500 mA g −1 ) after 110 cycles, and the synergetic properties of p-SiO@C further presents good cycling stability (777.1 mA h g −1 , at 500 mA g −1 after 300 cycles) and excellent rate capability (977 mA h g −1 , at 1000 mA g −1 ). The low-temperature fabrication of p-SiO followed by carbonization is promoting for practical application in high-performance Si-based lithium-ion battery.