Spherical electrochemically active-material structures comprising high-capacity materials and battery electrodes comprising thereof

Abstract

Described herein are electrochemically active-material structures comprising high-capacity materials. The mean largest cross-sectional dimension of these structures is kept below the pulverization threshold, which corresponds to the structures' composition. As such, the structure fracturing during battery cycling is reduced thereby preserving the battery capacity. Furthermore, these structures have a sphericity of at least about 0.9. Such high sphericity values translate into a small surface area for a given volume thereby reducing the electrolyte decomposition and solid electrolyte interphase (SEI) formation on the surface of these structures. Furthermore, the small size and high sphericity help to keep swelling substantially isotropic nature. The small structure size also helps with preserving the initially formed SEI layer thereby limiting this SEI formation to initial cycles. Finally, the initial distribution, layer porosity, small size, and sphericity help to reduce the coalescence of these structures during cycling, e.g., typically caused by Li-assisted electrochemical welding.