SILICON-SILICON OXIDE-LITHIUM COMPOSITE MATERIAL HAVING NANO SILICON PARTICLES EMBEDDED IN A SILICON:SILICON LITHIUM SILICATE COMPOSITE MATRIX, AND A PROCESS FOR MANUFACTURE THEREOF

摘要

A process for producing a silicon:silicon oxide: lithium composite (SSLC) material useful as a negative electrode active material for non-aqueous battery cells includes: producing a partially lithiated SSLC material by way of mechanical mixing; subsequently producing a further prelithiated SSLC material by way of spontaneous lithiation procedure; and subsequently producing a delithiated SSLC material by way of reacting lithium silicide within the dispersed prelithiated SSLC material with organic solvent(s) to extract lithium from the prelithiated SSLC material, until reactivity of lithium silicide within the prelithiated SSLC material with the organic solvent(s) ceases. The delithiated SSLC material is a porous plastically deformable matrix having nano silicon embedded therein. The delithiated SSLC material can have a lithium silicide content of less than 0.5% by weight. A battery cell having as its negative electrode active material an SSLC material as set forth herein can exhibit an irreversible capacity loss of less than 10%.

主权项

1. A method for producing a silicon:silicon oxide: lithium composite (SSLC) material, comprising:
performing a prelithiation process to produce a prelithiated SSLC material, the prelithiation process comprising:
producing a partially lithiated SSLC material by way of a mechanical mixing procedure comprising milling silicon oxide powder and lithium powder; andproducing a further prelithiated SSLC material by way of a spontaneous lithiation procedure comprising:
compressing the partially lithiated SSLC material matrix material; andexposing the compressed partially lithiated SSLC material to an lithium based electrolyte,wherein spontaneous lithiation procedure completes reaction of unreacted lithium and SiOx in the partially lithiated SSLC material, until unreacted lithium disappears and a uniform composition of lithium silicides is achieved in the SSLC material by lithium diffusion; performing a delithiation process following the prelithiation process to produce a delithiated SSLC material, the delithiation process comprising:
dispersing the compressed further prelithiated SSLC material in a liquid carrier medium to thereby produce a dispersed prelithiated SSLC material; andexposing the dispersed prelithiated SSLC material to a volume of one or more organic solvents to thereby react lithium silicide within the dispersed prelithiated SSLC material with the one or more organic solvents and extract lithium from the dispersed prelithiated SSLC material, until reactivity of lithium silicide within the dispersed prelithiated SSLC material with the one or more organic solvents ceases, wherein the volume of the one or more organic solvents acts as a reservoir with respect to reacting with lithium silicide within the dispersed prelithiated SSLC material, wherein the delithiated SSLC material comprises a porous plastically deformable Si:lithium silicate composite (Si:LSC) matrix having nano silicon particles embedded therein.