Solid state pretreatment of active materials for negative electrodes in electrochemical cells

Abstract

Provided are methods for solid state pretreatment of active materials (e.g., prelithiation of silicon monoxide) while forming treated negative active material structures. Also provided are the formed structures, negative electrodes comprising these structures, and electrochemical cells comprising these electrodes. In some examples, silicon monoxide structures are mixed with lithium hydroxide structures or some other lithium-containing structures. The mixture is heated in an inert environment to form treated negative active material structures. These treated structures comprise various lithium-containing components, some of which trap lithium. When an electrochemical cell, formed with these treated negative active material structures, is initially charged and additional new lithium ions are introduced into the negative electrodes (e.g., from the positive electrode), a larger portion of these new lithium ions forms reversible components (rather than irreversible components) in the negative electrode than, for example, in a conventional cell without any such treatment.