Silicon-based electroactive materials for sodium-ion batteries and methods of manufacturing the same

A method of manufacturing a negative electrode for a battery that cycles sodium ions, the method comprising:

• extracting alkali metal ions or alkaline earth metal ions from a silicide precursor to form a silicon-based electroactive material, the silicide precursor comprising two-dimensional silicon layers having a hexagonal crystal structure and being spaced apart from one another by planar monolayers of alkali metal ions or alkaline earth metal ions, wherein the alkali metal ions or the alkaline earth metal ions are extracted from the silicide precursor such that the hexagonal crystal structure of the two-dimensional silicon layers is retained in the silicon-based electroactive material;
• and
• depositing a continuous layer comprising the silicon-based electroactive material on a metal substrate to form the negative electrode.

A method of manufacturing a negative electrode for a battery that cycles sodium ions, the method comprising:

• extracting calcium (Ca+) ions from a calcium silicide precursor to form a silicon-based electroactive material, the calcium silicide precursor comprising two-dimensional silicon layers having a hexagonal crystal structure and being spaced apart from one another by planar monolayers of calcium ions, wherein the calcium ions are extracted from the calcium silicide precursor such that the hexagonal crystal structure of the two-dimensional silicon layers is retained in the silicon-based electroactive material;
• and
• depositing a continuous layer comprising the silicon-based electroactive material on a metal substrate to form the negative electrode.