Double-buffer silicon-carbon anode material by a dynamic self-assembly process for lithium-ion batteries

The volume expansion of the silicon (Si) anode material is still a main bottle-neck problem limiting its battery application. Effective structure design needs to be studied continuously, meanwhile the process feasibility also cannot be ignored. Herein, a novel yet simple method to prepare double-buffer structure hybrids with a multilevel porous self-assembly structure induced by hydrogen bonding employing spray-drying methods is reported. The well-designed mesoporous hybrid with crosslinking conductive network shows multi-channels in the interior and carbon nanotubes (CNTs)-enhanced carbon protective layer in the exterior, which can effectively buffer the volume strain of Si and promote the electron/ion transfer. The hybrid anode presents a capacity of 1176.5 mAh g –1 with a high initial coulomb efficiency (ICE) of 87.04%, and maintains at 1006.6 mAh g –1 after 100 cycles with a current density of 200 mA g –1 . The material also exhibits good rate properties and cycle performance at a current density of 500 mA g –1 . The as-designed hybrid is promising in high-level Si-based anode material practical application, which is also important for prospective lithium ion battery industry.