Porous Solid Electrolyte Support for Thin Lithium-Ion Battery Layers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing solid electrolyte layers in all-solid-state batteries face challenges in forming a thin and uniform layer, leading to ion conduction deterioration and short circuits, while increasing thickness to prevent short circuits results in decreased volume energy density and increased internal resistance.
Innovation Solution
A support made of paper or nonwoven fabric with specific thermal dimensional change rates, air permeability, and post-heat-treatment bending resistances is used within the solid electrolyte layer to enhance interfacial adhesion, reduce internal resistance, and maintain a pass line of lithium ions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of stationary object
If the solid electrolyte layer thickness is reduced to enhance volume energy density, then volume energy density is improved, but ion conduction deteriorates and short circuits occur
Solution Approach 1:
The support is designed with a porous structure (porosity of 30-80%) that allows efficient lithium ion transport while maintaining mechanical integrity. The porous structure provides multiple pathways for ion conduction, compensating for the reduced thickness and preventing short circuits even in thin layers.
Solution Approach 2:
The invention uses a composite structure combining a porous support (paper or nonwoven fabric) with solid electrolyte. This composite material provides both the mechanical strength needed for thin-layer stability and the ion-conducting properties required for high performance, resolving the contradiction between thinness and reliability.
2Reliability
If the solid electrolyte layer thickness is increased to prevent short circuits, then short circuit prevention is improved, but volume energy density decreases and internal resistance increases
Solution Approach 1:
The porous support structure provides mechanical reinforcement and multiple ion transport pathways, enabling the use of thinner solid electrolyte layers while maintaining short circuit prevention. The porosity creates a three-dimensional network that distributes stress and prevents direct contact between electrodes.
3Reliability
If the solid electrolyte layer thickness is reduced to decrease internal resistance, then internal resistance is reduced, but manufacturing stability deteriorates and cracks occur
Solution Approach 1:
The porous support acts as an intermediary substrate that provides mechanical strength and dimensional stability to the thin solid electrolyte layer. It serves as a scaffold that prevents cracking during handling and manufacturing processes while allowing efficient ion transport through its porous structure.
Solution Approach 2:
The porous structure of the support provides flexibility and stress distribution, preventing crack formation in thin solid electrolyte layers during manufacturing and handling. The interconnected pores allow the structure to accommodate dimensional changes without fracturing.
4Volume of stationary object
If a thin-film sheet is used as support to enable thin solid electrolyte layer, then volume energy density is improved, but the sheet breaks or cracks during handling
Solution Approach 1:
The porous structure (paper or nonwoven fabric) provides high specific strength and flexibility, enabling the thin-film support to resist breaking and cracking during handling. The three-dimensional fiber network distributes mechanical stresses, preventing localized failure even in very thin configurations.
Solution Approach 2:
The support structure provides localized mechanical reinforcement where needed while maintaining overall thinness. The porous network distributes mechanical loads across the entire structure, providing strength at critical points without increasing overall thickness.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The proposed support reduces interfacial resistance between electrodes and the solid electrolyte layer, improves permeability of the solid electrolyte, and prevents deformation of the support during integration, resulting in a solid electrolyte layer with low internal resistance and improved battery performance.
Implementation Method 1
thermal dimensional change rates in a machine direction and a cross direction are both −10 to 5%
Implementation Method 2
a function of ion conduction of lithium ions between the positive electrode and the negative electrode
Implementation Method 3
air permeability is 1 to 50 L/cm2/min.
Data Source
AI summary
A support for a lithium ion secondary battery is included in a solid electrolyte layer of a lithium ion secondary battery, wherein the support is paper or a nonwoven fabric in which the thermal dimensional change rates in the machine direction and cross direction are both −10 to 5%, the air permeability is 1 to 50 L/cm2/min., and the post-heat-treatment bending resistances in the machine direction and the cross direction are in the range of 5 to 250 mN.