Solid-State Battery Laminate to Prevent Barrier Layer Deterioration
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Solution Overview
Problem
All-solid-state batteries face delamination issues between the solid electrolyte and active material layers due to expansion and shrinkage during charge/discharge cycles, leading to battery deterioration, and the use of film-shaped exterior materials for shape diversification and weight reduction poses risks of barrier layer deterioration under high-pressure constraint.
Innovation Solution
Incorporating a barrier layer protective film made of chromium on the surface of the barrier layer in the exterior material to prevent direct contact and potential alloy formation, thereby suppressing deterioration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If a film-shaped exterior material with a barrier layer is used for shape diversification and weight reduction, then the battery can achieve thinner and lighter design with diversified shapes, but the barrier layer may come into contact with the solid electrolyte under high-pressure constraint, leading to alloy formation and deterioration of the barrier layer
Solution Approach 1:
The heat-sealable resin layer serves as an intermediary between the barrier layer and the solid electrolyte. This intermediate layer prevents direct contact between the barrier layer and solid electrolyte even under high-pressure constraint conditions, thereby avoiding alloy formation and barrier layer deterioration while maintaining the benefits of film-shaped exterior materials
Solution Approach 2:
The exterior material is designed as a composite laminate structure comprising a base material layer, a barrier layer, and a heat-sealable resin layer. This composite structure combines the advantages of different materials: the base material provides mechanical strength, the barrier layer prevents moisture penetration, and the heat-sealable resin layer provides protection against direct contact with the solid electrolyte under pressure
2Stability of the object's composition
If the all-solid-state battery is continuously constrained in a high-pressure state to suppress delamination, then delamination between solid electrolyte and active material layers is suppressed, but the heat-sealable resin layer thickness decreases, causing the barrier layer to come into contact with the solid electrolyte
Solution Approach 1:
The heat-sealable resin layer is designed with sufficient initial thickness to act as a cushioning layer that prevents direct contact between the barrier layer and solid electrolyte even when the battery is continuously constrained under high pressure during charge/discharge cycles, thereby preventing alloy formation and barrier layer deterioration
Data Source
AI summary
An all-solid-state battery contained in an exterior material having a barrier layer in which deterioration is effectively suppressed even when the all-solid-state battery is constrained in a high-pressure state. The all-solid-state battery has a battery element contained in a package formed of an exterior material, the battery element includes at least a unit cell including: a positive electrode active material layer; a negative electrode active material layer; and a solid electrolyte layer laminated between the positive electrode active material layer and the negative electrode active material layer, wherein the exterior material is composed of a laminate having, in the following order: at least a barrier layer; a barrier layer protection film formed on the surface of the barrier layer; and a heat-fusible resin layer.