Gel Separating Membrane for Flexible Battery Design

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current lithium ion battery manufacturing methods require a liquid electrolytic solution for assembly, resulting in inflexible batteries with limited shape options and a complex assembly process, particularly unsuitable for applications requiring non-planar separators.

Innovation Solution

A method for manufacturing a gel-form separating membrane using an extrusion process with a mix of alkali metal salt, dinitrile compound, and hot melt polymer, allowing for flexible and deformable membranes in various shapes, eliminating the need for a specific solvent and simplifying the assembly process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a liquid electrolytic solution is used for assembly, then the separator can be properly impregnated, but the battery becomes inflexible and the assembly process becomes complex

Engineering Contradiction:

Improveseparator impregnationVSAvoidbattery flexibility

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent changes the physical state of the electrolyte from liquid to gel form. The gel electrolyte comprises a polymer matrix (such as polyacrylonitrile, polyvinylidene fluoride, or carboxymethyl cellulose) combined with lithium salt and solvent, creating a semi-solid state that maintains ionic conductivity while providing mechanical flexibility and structural integrity.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite gel electrolyte system by combining polymer materials with lithium salts and solvents. This composite structure integrates the ionic conductivity of liquid electrolytes with the mechanical properties of solid polymers, enabling both proper separator impregnation and battery flexibility.

Inventive Principle:

Principle #40Composite materials

2Reliability

If a liquid electrolytic solution is used for assembly, then the separator can be properly impregnated, but the assembly process becomes complex with multiple steps

Engineering Contradiction:

Improveseparator impregnationVSAvoidassembly process

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the electrolyte filling step with the separator impregnation step by using gel electrolyte that can be directly applied to the separator. The gel structure allows it to be incorporated into the separator matrix during manufacturing, eliminating the need for separate filling and impregnation operations required by liquid electrolytes.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The gel electrolyte is prepared in advance with the appropriate polymer-salt-solvent composition, allowing it to be directly applied to the separator in a single step. This preliminary preparation of the gel structure enables direct impregnation without requiring multiple processing steps.

Inventive Principle:

Principle #10Preliminary action

3Ease of manufacture

If traditional assembly methods are used, then liquid electrolytes can be introduced, but the battery shape is limited to standard forms

Engineering Contradiction:

Improveelectrolyte introductionVSAvoidbattery form

Core Design Contradiction:

Ease of manufactureVSShape

Solution Approach 1:

The patent changes the electrolyte from liquid to gel state, which allows the electrolyte to maintain its shape and structure in various battery configurations. The gel's semi-solid properties enable it to conform to non-planar and three-dimensional battery shapes while maintaining ionic conductivity and structural integrity.

Inventive Principle:

Principle #35Parameter changes

4Ease of manufacture

If plane separators are used, then assembly is simple, but textile and other applications requiring non-planar separators are limited

Engineering Contradiction:

Improveassembly simplicityVSAvoidseparator shape

Core Design Contradiction:

Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent changes the separator from a rigid plane structure to a flexible gel-form structure. The gel electrolyte separator can be manufactured in various shapes including non-planar, three-dimensional, and textile-compatible forms while maintaining the necessary ionic conductivity and mechanical properties for battery operation.

Inventive Principle:

Principle #35Parameter changes

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 method produces membranes with enhanced mechanical strength and ionic conductivity, enabling flexible and shape-variable battery designs, such as wires and tubes, while reducing assembly complexity and eliminating the need for solvent evaporation steps.

Implementation Method 1

a hot melt polymer support, with a glass transition temperature Tg, soluble in the dinitrile compound

Methodology Applied

Scientific EffectSolubilization: Solvation

Implementation Method 2

a step of extruding a mix comprising

Methodology Applied

Scientific EffectExtrusion: Extrusion

Data Source

PatentUS10686174B2Method for manufacturing a separating membrane for an accumulator

Publication Date: 2020.06.16 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES

AI summary

The invention relates to a method of manufacturing a separating membrane in gel form, for an alkali metal ion battery, the method consisting of extruding a mix comprising:an alkali metal salt,a dinitrile compound with formula N≡C—R—C≡N, in which R is a hydrocarbon group CnH2n, and n is equal to 1 or 2 and preferably equal to 2,a hot melt support polymer, soluble in the dinitrile compound.