Gel-Forming Non-Porous Battery Separator Against Micro-Shorts

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Solution Overview

Problem

Conventional porous separators in lithium-ion batteries are prone to micro-short circuits due to foreign matter introduction and have low mechanical strength, leading to safety and reliability issues.

Innovation Solution

A non-porous separator is developed by combining two or more macromolecular materials, where at least one material can be gelled by an organic solvent, effectively preventing micro-short circuits and enhancing mechanical strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a porous separator is used to ensure electrochemical performance, then ion conductivity is improved, but the risk of micro-short circuits increases due to foreign matter penetration through pores

Engineering Contradiction:
Improvebattery safetyVSAvoidmicro-short circuit risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention uses a non-porous separator material that eliminates pore structures entirely, preventing foreign matter penetration while maintaining electrochemical performance through alternative ion transport mechanisms in the gel polymer electrolyte matrix

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The invention creates a composite separator structure combining a porous polymer base layer with a gel polymer electrolyte coating layer, where the coating layer provides the non-porous barrier function while the porous base layer provides mechanical support and initial ion transport pathways

Inventive Principle:
Principle #40Composite materials

2Reliability

If the porosity of the separator is increased to improve electrochemical performance, then ion transport is enhanced, but the mechanical strength decreases

Engineering Contradiction:
Improveelectrochemical performanceVSAvoidmechanical strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The invention divides the separator into two functional segments: a porous polymer base layer that provides mechanical strength and structural support, and a gel polymer electrolyte coating layer that provides enhanced ion transport and non-porous barrier properties

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention creates a composite structure where the porous polymer base layer contributes mechanical strength while the gel polymer electrolyte coating layer contributes enhanced ion conductivity and safety properties

Inventive Principle:
Principle #40Composite materials

3Reliability

If a gel polymer electrolyte is used to improve conductivity and thermal stability, then electrochemical performance is enhanced, but the mechanical strength remains low

Engineering Contradiction:
Improveelectrochemical performanceVSAvoidmechanical strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The invention merges the gel polymer electrolyte with a porous polymer base layer to create a composite separator where the base layer provides the mechanical strength that the gel polymer alone lacks, while the gel polymer provides enhanced electrochemical performance

Inventive Principle:
Principle #5Merging (Combining)

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 non-porous separator significantly improves the qualification rate and cycle life of lithium-ion batteries, while preventing micro-short circuits and enhancing safety.

Implementation Method 1

contains macromolecular materials that are gellable by an organic solvent in the electrolytic solution, and form a gel polymer electrolyte upon the addition of the electrolytic solution

Methodology Applied
Scientific EffectGelation: Gel

Data Source

PatentEP3439070B1Non-porous separator and use thereof
Publication Date: 2025.02.19 DKJ NEW ENERGY S & T CO LTD

AI summary

The present invention belongs to the technical fields of macromolecular materials and batteries, and particularly relates to a non-porous separator and the use thereof, more particularly to a non-porous separator having a gelation function and the use thereof. This non-porous separator is composed of two or more macromolecular materials, wherein at least one of the macromolecular materials can be gelled by an organic solvent. This non-porous separator can be used in batteries having an organic solvent-based electrolyte and a high energy density, such that not only can a micro-short circuit, generated due to the introduction of foreign matters such as metals, be prevented, leading to an improved qualification rate for the product, but also the safety performance and the cycle life of such a battery can be improved significantly.