Controllable synthesis of silicon/carbon microspheres alternating carbon and silicon shells for high-energy lithium-ion batteries

The poor cycling stability and huge volume change of silicon during the charge/discharge processes have seriously hindered the extensive application. In order to deal with address various challenges, silicon/carbon microspheres (SCM) are designed via nonsynchronous nucleation, hydrothermal coupling method and magnesium thermal reduction method. The silicon/carbon microspheres with two carbon shells (SCM-2) delivers the most enhanced initial charge capacity of 2455 mAh g–1 at 0.1 C, and reveals the highest specific capacity of 2178 mAh g–1 after 200 cycles and capacity retention of 98% after 500 cycles at 2 C. The SCM-2//LiCoO2 full cell can maintain high capacity of 159.2 mAh g–1 and no capacity decay after 500 cycles at 0.1 C. It is demonstrated that the fabrication for silicon/carbon microspheres is a convenient and effective strategy to resolve the practical application silicon anode material in lithium-ion batteries.