Solid Electrolyte Layer Flexibility and Ion Conductivity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ion conductivity in solid electrolyte layers and electrode layers decreases due to the addition of binders, which compromises the compatibility between flexibility and ion conductivity in all-solid lithium batteries.
Innovation Solution
A solid electrolyte layer comprising a sulfide solid electrolyte material with minimal cross-linking sulfur and a branched polymer, such as hydrogenated Li2S—P2S5 with a specific mol ratio, is used to maintain ion conductivity while providing flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a binder is added to a solid electrolyte layer or electrode layer, then flexibility is improved, but ion conductivity decreases
Solution Approach 1:
The patent changes the chemical composition parameters of the binder by specifying a hydrogenated block copolymer with particular structural characteristics (hydrogenated portion content of 5-50 mass%, specific molecular weight range). This parameter optimization allows the binder to provide flexibility while minimizing its negative impact on ion conductivity, resolving the contradiction between these two properties.
Solution Approach 2:
The patent creates a composite binder system using a hydrogenated block copolymer that combines different functional segments - a hard segment providing structural integrity and flexibility, and a soft segment providing ion conductivity pathways. This composite structure allows the binder to simultaneously deliver both flexibility and maintained ion conductivity.
2Ease of manufacture
If a polymer binder is added to improve workability and moldability, then flexibility is improved, but ion conductivity decreases
Solution Approach 1:
The patent optimizes the molecular weight and hydrogenation degree of the polymer binder to specific ranges that balance processability with electrical performance. By controlling these parameters, the binder provides sufficient flexibility for manufacturing while maintaining adequate ion conductivity for battery operation.
Data Source
AI summary
A main object of the present invention is to provide a solid electrolyte layer having flexibility, in which ion conductivity is inhibited from decreasing. The present invention attains the above-mentioned object by providing a solid electrolyte layer including a sulfide solid electrolyte material not having cross-linking sulfur substantially and a branched polymer for binding the above-mentioned sulfide solid electrolyte material.