A novel strategy for the synthesis of highly stable ternary SiOx composites for Li-ion-battery anodes

SiOx is a promising anode material for lithium-ion batteries (LIBs) due to its relatively high capacity. Nevertheless, the poor conductivity and the large volume expansion of SiOx upon Li+ insertion/extraction limit its applications. Herein, a novel strategy for preparing ternary Ni/SiOx/nitrogen-doped carbon (NSC) composites has been developed through in-situ transformation of the Ni3Si2O5(OH)4/nitrogen-doped carbon precursor derived from dried bamboo leaves. The 3D interconnected SiOx/nitrogen-doped carbon (SC) framework provides sufficient void space for relieving the volume change during lithiation process while facilitating the electrolyte infiltration and lithium ion diffusion processes. The growth of uniform Ni nanoparticles (NPs) on the surface of the SC matrix restricts the formation of cracks, reduces volume expansion during lithiation process, and effectively improves the electrical conductivity of SiOx. The optimized sample delivers a high discharge capacity of 864.6 mA h g-1 after 70 cycles at 200 mA g-1 and superior rate capability of 289.8 mA h g-1 at 10 A g-1. The electrode delivers a capacity of 427.6 mA h g-1 even at 5 A g-1 after 1000 cycles along with an outstanding capacity retention (~ 100%). Our method provides insight into the utilization of biomass towards high performance energy storage through simple and low-cost procedures.