All-Solid-State Battery Anode Pre-Lithiation for Stable SEI

The patent applies preliminary action by performing pre-lithiation of the negative electrode before assembling the battery. A lithium layer is disposed on the negative electrode active material layer, and the electrode is dipped in an organic solvent to enable lithium ions to penetrate and form a stable SEI layer. This preliminary lithium insertion compensates for lithium loss during initial charging and establishes a stable interface before the battery enters normal operation, thereby improving initial efficiency while maintaining the safety benefits of solid electrolytes.

The patent uses an organic solvent as an intermediary medium to facilitate the formation of a stable solid electrolyte interphase (SEI) layer. The solvent, containing lithium salts, acts as a mediator that enables controlled lithium ion penetration and SEI formation on the negative electrode surface. This intermediary process creates a stable interface between the solid electrolyte and negative electrode, reducing subsequent side reactions and improving initial efficiency without compromising the inherent safety of the solid electrolyte system.

The patent performs pre-lithiation as a preliminary action before battery assembly to prevent performance degradation during cycling. By disposing a lithium layer on the negative electrode and dipping it in an organic solvent, lithium ions are pre-inserted into the electrode structure and a stable SEI layer is formed. This preliminary treatment compensates for irreversible lithium consumption that would otherwise occur during the first charge cycle, ensuring better capacity retention and extended cycle life while maintaining the safety advantages of solid electrolytes.

The patent changes the chemical and physical parameters of the negative electrode surface through pre-lithiation treatment. The organic solvent dipping process modifies the surface composition and structure by facilitating SEI layer formation with specific lithium salt concentrations and solvent properties. These parameter changes create a more stable electrode-electrolyte interface that resists degradation during cycling, thereby extending battery life while preserving the intrinsic safety of the solid electrolyte system.