Solid Electrolyte Sheet Pore Design for Short-Circuit Resistance
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Solution Overview
Problem
Conventional solid-state batteries face issues with increased battery resistance and the risk of short circuits due to large pore diameters in nonwoven fabrics and the potential penetration of metal foreign matter during the manufacturing process.
Innovation Solution
A solid electrolyte sheet with a nonwoven fabric having a pore diameter of 15 μm or less and a pore diameter to particle diameter ratio of 5.0 or more, ensuring the solid electrolyte is densely disposed within the fabric, preventing metal foreign matter penetration and reducing battery resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a nonwoven fabric with large pore diameter is used in the solid electrolyte sheet, then the manufacturing process is easier and material retention is better, but metal foreign matter can penetrate through the pores causing short circuits
Solution Approach 1:
The patent utilizes a nonwoven fabric with specifically controlled pore diameter (15 μm or less) to create a porous structure that prevents metal foreign matter penetration while maintaining lithium ion conductivity. The pore size is optimized to be smaller than metal particles (20 μm) but sufficient for lithium ion transport, resolving the contradiction between reliability and harmful factor prevention.
Solution Approach 2:
The patent changes the critical parameter of pore diameter to 15 μm or less, which fundamentally alters the fabric's interaction with metal foreign matter. This parameter change ensures that metal particles cannot penetrate through the pores, preventing short circuits while maintaining the necessary porosity for battery operation.
2Reliability
If the pore diameter of nonwoven fabric is reduced to prevent metal penetration, then short circuit risk decreases, but battery resistance increases due to poor solid electrolyte retention
Solution Approach 1:
The nonwoven fabric with 15 μm or less pore diameter provides an optimal porous structure that simultaneously achieves metal foreign matter prevention and solid electrolyte retention. The controlled porosity ensures lithium ion conductivity while the pore size limitation prevents metal particle penetration, resolving the contradiction between reliability and manufacturing precision.
Solution Approach 2:
The patent creates a composite structure combining nonwoven fabric with solid electrolyte particles. This composite material integrates the mechanical support and porous structure of the fabric with the ionic conductivity of the solid electrolyte, achieving both metal penetration prevention and low battery resistance through the synergistic combination of materials.
3Weight of moving object
If a nonwoven fabric with mass per square meter of 8 g or less is used, then the battery structure is lighter and more compact, but the fabric lacks sufficient strength to retain solid electrolyte during pressing
Solution Approach 1:
The patent changes the mass per square meter parameter to 8 g or less while compensating for strength requirements through optimized pore diameter control (15 μm or less). This parameter change achieves weight reduction while the specific pore structure provides sufficient mechanical support for solid electrolyte retention during the pressing process.
Solution Approach 2:
The controlled porous structure with 15 μm or less pore diameter provides both weight reduction and mechanical strength. The optimized porosity creates a lightweight fabric that nonetheless maintains sufficient structural integrity to retain solid electrolyte particles during battery assembly pressing, resolving the contradiction between weight and strength.
Data Source
AI summary
A solid electrolyte sheet of the present disclosure comprises a nonwoven fabric and a solid electrolyte disposed inside the nonwoven fabric. The pore diameter of the nonwoven fabric is 15 μm or less. The ratio of the pore diameter relative to a particle diameter of the solid electrolyte (pore diameter/particle diameter) is 5.0 or more.