A Yolk-Shell Design for Stabilized and Scalable Li-Ion Battery Alloy Anodes

Silicon is regarded as one of the most promising anode materials for next generation lithium-ion batteries. For use in practical applications, a Si electrode must have high capacity, long cycle life, high efficiency, and the fabrication must be industrially scalable. Here, we design and fabricate a yolk-shell structure to meet all these needs. The fabrication is carried out without special equipment and mostly at room temperature. Commercially available Si nanoparticles are completely sealed inside conformal, thin, self-supporting carbon shells, with rationally designed void space in between the particles and the shell. The well-defined void space allows the Si particles to expand freely without breaking the…