Negative Electrode with Inorganic Layer for Lithium Secondary Batteries

An inorganic material layer (such as Al2O3, SiO2, or ZrO2) is introduced as an intermediary between the lithium-containing first layer and the external environment. This intermediary layer prevents direct contact between lithium and oxygen, thereby blocking the formation of native oxide films while allowing the lithium layer to function in resolving irreversible capacity issues.

The inorganic material layer creates an inert environment for the lithium-containing first layer by providing a protective barrier that excludes oxygen and moisture. This inert environment prevents oxidation reactions that would otherwise form harmful native oxide films on the lithium surface.

The patent replaces the solution spraying method (fluid-based) with a vacuum deposition method (physical vapor deposition). This substitution allows for precise control of layer thickness and uniformity by controlling deposition parameters such as deposition time, temperature, and vacuum level, rather than relying on solution concentration and spray dynamics which lead to non-uniform and excessively thick layers.

The patent changes the fundamental parameters of the layer formation process by transitioning from wet chemical deposition (solution spraying) to physical vapor deposition (vacuum deposition). This parameter change enables precise control over layer thickness and uniformity, producing thin, uniform lithium-containing layers without the excessive thickness and non-uniformity characteristic of solution spraying methods.