Grape-liked Si@Na2SiO3 composites for stable lithium storage though a metal salt-assisted chemical etching approach

Serious volume expansion for silicon-based material has extremely restricted its widespread application. Herein, Si@Na 2 SiO 3 composite with grape-liked structure was fabricated by a simple metal salt-assisted chemical etching method, which is enabled by the high corrosivity of NaHCO 3 . The gelatinous Na 2 SiO 3 can evenly coat the surface of Si nanoparticles, then efficiently inhibiting volume expansion. Meanwhile, porous structures etched by NaHCO 3 provide more diffusion channels for Li + . Si@Na 2 SiO 3 exhibits excellent cycling and rate properties: the discharge capacity of 1140.16mAh g −1 at 0.5 A g -1 after 100th cycling and the stable discharge capacity of 1565.64 mAh g −1 at 2.0 A g −1 . This research provides a simple and effective technology to exploit the high-capacity silicon-based anode material.