All solid state battery
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Solution Overview
Problem
Existing all solid state batteries face challenges in achieving excellent cycle characteristics due to anisotropy in the tensile strength of nonwoven fabrics used in their electrolyte layers, leading to non-uniform stress distribution and potential internal short circuits.
Innovation Solution
The battery design incorporates first and second solid electrolyte layers with nonwoven fabrics oriented at an angle of 45° to 90° relative to each other, ensuring balanced tensile strength and symmetry, thereby moderating anisotropy and enhancing cycle characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If nonwoven fabric is used in the solid electrolyte layer, then the battery structure is simplified and safety is improved, but anisotropy in tensile strength causes non-uniform stress distribution leading to poor cycle characteristics
Solution Approach 1:
The patent applies asymmetry by orienting the fabric directions of multiple nonwoven fabric layers at different angles (e.g., 0° and 90°, or 45° and 135°) relative to each other. This asymmetric arrangement compensates for the inherent anisotropy of individual nonwoven fabric layers, creating a more isotropic composite structure that distributes stress uniformly in all directions, thereby improving cycle characteristics while maintaining the simplified battery structure
2Reliability
If nonwoven fabric with high void rate is used, then ion conductivity is improved, but mechanical strength and structural stability deteriorate
Solution Approach 1:
The patent uses composite materials by combining multiple nonwoven fabric layers with different fabric directions, each having high void rates for good ion conductivity. The layered composite structure provides both the porosity needed for ion transport and the mechanical strength through the combined architecture, where each layer contributes to overall structural stability while maintaining high ion conductivity
Data Source
AI summary
A main object of the present disclosure is to provide an all solid state battery with excellent cycle characteristics. The present disclosure achieves the object by providing an all solid state battery comprising, in an order of, a cathode CA1, a first solid electrolyte layer, an anode AN, a second solid electrolyte layer, and a cathode CA2, along a thickness direction, wherein: the first solid electrolyte layer contains a first nonwoven fabric, and a first solid electrolyte arranged inside the first nonwoven fabric; the second solid electrolyte layer contains a second nonwoven fabric, and a second solid electrolyte arranged inside the second nonwoven fabric; and in a plan view along the thickness direction, an angle formed by a first fabric direction in the first nonwoven fabric and a second fabric direction in the second nonwoven fabric is 45° or more and 90° or less.