CORE-SHELL ELECTROCHEMICALLY ACTIVE PARTICLES WITH MODIFIED MICROSTRUCTURE AND USE FOR SECONDARY BATTERY ELECTRODES

Provided are electrochemically active materials capable of absorbing and desorbing an ion suitable for use in secondary cells. The provided materials include a core consisting of a plurality of silicon particulates of a particle size less than 1 micrometer, the particulates intermixed with and surrounded by a silicon metal alloy composite, and an electrochemically active buffering shell layer enveloping at least a portion of the core such that the resulting electrochemically active material has an overall particle size with a maximum linear dimension of greater than one micrometer.