Composition for electrochemical element functional layers, method for producing said composition, functional layer for electrochemical elements, multilayer body for electrochemical elements, and electrochemical element
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electrochemical device members with functional layers face challenges in maintaining thin thickness while enhancing adhesiveness and cycle characteristics, particularly when immersed in electrolyte solution.
Innovation Solution
A composition for an electrochemical device functional layer using a particulate polymer with a hydroxyl group surface localization rate of 25% or more and specific particle diameter distribution, combined with controlled polymerization conditions, to achieve high wet adhesiveness and improved cycle characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the functional layer thickness is reduced, then the device achieves compact size and high energy-density, but the wet adhesiveness of the functional layer deteriorates
Solution Approach 1:
The patent applies local quality by creating a particulate polymer with non-uniform hydroxyl group distribution, specifically localizing hydroxyl groups at the particle surface. This surface localization (25% or more of total hydroxyl groups) concentrates adhesive functionality at the critical interface between the functional layer and substrate, enabling thin layers to maintain high wet adhesiveness through enhanced surface chemistry rather than relying on increased thickness.
Solution Approach 2:
The patent changes the physical and chemical parameters of the particulate polymer, specifically controlling the particle diameter (D50: 1.0-10.0 μm, D99: 15.0 μm or less) and the hydroxyl group surface localization rate (25% or more). These parameter changes optimize the balance between packing density (affecting layer thickness) and surface adhesive properties, allowing thin functional layers to achieve sufficient wet adhesiveness.
2Volume of moving object
If the functional layer thickness is reduced, then the device achieves compact size, but the cycle characteristics of the electrochemical device deteriorate
Solution Approach 1:
By localizing hydroxyl groups at the particle surface of the particulate polymer, the patent enhances the interfacial bonding between the functional layer and substrate. This strong interfacial adhesion prevents delamination and structural collapse during repeated charging and discharging cycles, thereby improving cycle characteristics even when the functional layer is thin.
Solution Approach 2:
The patent uses a composite particulate polymer structure combining a polymer matrix with surface-localized hydroxyl groups. This composite structure provides both mechanical integrity (maintaining layer structure during cycling) and chemical adhesion (strong bonding to substrate), enabling thin functional layers to exhibit excellent cycle characteristics.
3Ease of manufacture
If conventional particulate polymers are used in the functional layer, then the manufacturing process is simple, but the wet adhesiveness and cycle characteristics are insufficient
Solution Approach 1:
The patent modifies the parameters of conventional particulate polymers by controlling the particle diameter distribution (D50: 1.0-10.0 μm, D99: 15.0 μm or less) and, crucially, the hydroxyl group surface localization rate (25% or more). These parameter changes can be achieved through controlled polymerization methods, maintaining manufacturing feasibility while dramatically improving wet adhesiveness and cycle characteristics.
4Ease of manufacture
If conventional particulate polymers are used in the functional layer, then the manufacturing process is simple, but the cycle characteristics deteriorate
Solution Approach 1:
The patent changes the chemical structure parameters of the particulate polymer by ensuring 25% or more of hydroxyl groups are localized at the particle surface. This structural modification enhances interfacial bonding and prevents structural collapse during cycling, improving reliability without significantly complicating the manufacturing process through controlled polymerization techniques.
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 functional layer exhibits high adhesiveness and enhances cycle characteristics of electrochemical devices, inhibiting thickening and structural collapse during charging and discharging.
Implementation Method 1
a particulate polymer that has a hydroxyl group surface localization rate of 25% or more as calculated according to formula (1)
Data Source
AI summary
A composition for an electrochemical device functional layer contains a particulate polymer having a particle diameter distribution that satisfies specific aspects and having a hydroxyl group surface localization rate of 25% or more.