Three-dimensional hierarchical ternary nanostructures for high-performance Li-ion battery anodes.

Silicon is considered one of the most promising anode materials for high-performance Li-ion batteries due to its 4200 mAh/g theoretical specific capacity, relative abundance, low cost, and environmental benignity. However, silicon experiences a dramatic volume change (∼300%) during full charge/discharge cycling, leading to severe capacity decay and poor cycling stability. Here, we report a three-dimensional (3D) ternary silicon nanoparticles/conducting polymer/carbon nanotubes hybrid anode material for Li-ion batteries. The hierarchical conductive hydrogel framework with carbon nanotubes as the electronic fortifier offers a continuous electron transport network and high porosity to accommodate the volume expansion of Si particles. By 3D wrapping of silicon nanoparticles/single-wall carbon nanotubes with conducting polymer nanostructures, a greatly improved cycling performance is achieved with reversible discharge capacity over 1600 mAh/g and 86% capacity retention over 1000 cycles at the current rate of 3.3 A/g. Our findings represent a new direction for fabricating robust, high-performance lithium-ion batteries and related energy storage applications with advanced nanostructured materials.