Wound Battery Separator Adhesive Layout for Electrolyte Impregnation

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Solution Overview

Problem

Existing battery designs face challenges in achieving both suitable formability and electrolyte impregnation ability, as excessive adhesive on separators can hinder electrolyte penetration while minimal adhesive may compromise the structural integrity of the wound electrode body.

Innovation Solution

A battery design where the separator has an adhesive layer with varying weight per area along its longitudinal direction, strategically positioned to enhance formability and prevent excessive adhesive formation, ensuring both adequate electrolyte impregnation and structural stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If an adhesive is applied onto the entire surface of a separator, then the formability of the wound electrode body is improved, but the impregnation ability with electrolyte deteriorates

Engineering Contradiction:

Improveformability of wound electrode bodyVSAvoidimpregnation ability with electrolyte

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The adhesive layer is applied selectively to specific regions of the separator rather than the entire surface. The weight per area of the adhesive layer varies in the longitudinal direction, with higher adhesive content in regions requiring stronger bonding and lower adhesive content in regions requiring better electrolyte penetration. This local differentiation resolves the contradiction by providing sufficient formability where needed while maintaining impregnation ability in other areas.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The weight per area of the adhesive layer is varied as a parameter along the longitudinal direction of the separator. By changing this physical parameter (adhesive quantity) across different regions, the patent achieves both adequate formability (where higher weight per area is applied) and sufficient impregnation ability (where lower weight per area is applied), thus resolving the technical contradiction between these two opposing requirements.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If no adhesive is applied to the separator, then the impregnation ability with electrolyte is improved, but the formability of the wound electrode body deteriorates

Engineering Contradiction:

Improveimpregnation ability with electrolyteVSAvoidformability of wound electrode body

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

Instead of applying adhesive uniformly or not at all, the patent applies adhesive with locally differentiated weight per area in the longitudinal direction. This ensures that regions requiring formability support receive adequate adhesive, while regions requiring electrolyte access receive minimal adhesive, thus resolving the contradiction between formability and impregnation ability.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent applies adhesive partially rather than completely across the entire separator surface. By using partial action (applying adhesive only to specific regions with varying weight per area), the patent achieves sufficient formability without excessive adhesive that would hinder electrolyte impregnation, thus resolving the technical contradiction.

Inventive Principle:

Principle #16Partial or excessive action

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

This configuration balances formability and electrolyte impregnation ability, reducing spring back and maintaining battery performance by optimizing adhesive distribution on the separator.

Implementation Method 1

The separator includes an adhesive layer disposed on at least a surface of the separator

Methodology Applied

Scientific EffectAdhesion: Adhesive

Implementation Method 2

a wound electrode body is not easily impregnated with an electrolyte

Methodology Applied

Scientific EffectPermeation: Permeation

Data Source

PatentUS20240039121A1battery

Publication Date: 2024.02.01 PRIME PLANET ENERGY & SOLUTIONS INC

AI summary

A battery disclosed here includes a positive electrode including a positive electrode active material layer, a negative electrode including a negative electrode active material layer, a separator, and a wound electrode body in which the positive electrode and the negative electrode are wound with the separator interposed therebetween. The separator includes an adhesive layer on at least one surface of the separator. The adhesive layer has a different weight per area in a longitudinal direction of the separator.