Laminated Battery Cell Separator Folding for Electrode Alignment

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Solution Overview

Problem

Laminated battery cells suffer from misalignment of negative and positive electrode sheets, leading to incomplete intercalation of lithium ions, which results in lithium precipitation, reducing cycle life, fast charging capacity, and posing safety hazards like combustion and explosion.

Innovation Solution

A thermal composite laminated cell design with alternately stacked negative and positive electrode sheets separated by a separator with incomplete-cut-off structures, allowing precise folding and alignment, and using single-sided electrode sheets on outermost sides to reduce material usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If electrode sheets are in a free-fall state during the laminated process, then the manufacturing process is simple, but the alignment of negative and positive electrode sheets is poor

Engineering Contradiction:

Improvelaminated process simplicityVSAvoidelectrode sheet alignment

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The separator acts as an intermediary component between negative and positive electrode sheets. By attaching electrode sheets to the separator in advance, the separator serves as a carrier that maintains proper alignment during the folding and assembly process, eliminating the need for complex alignment mechanisms while ensuring precise electrode positioning in the final cell structure.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Manufacturing precision

If a reshaping cylinder is used to clamp the cell from two sides, then the alignment of electrode sheets is improved, but powder falls off the electrode sheets increasing short circuit risk

Engineering Contradiction:

Improveelectrode sheet alignmentVSAvoidpowder falling off and short circuit risk

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The separator with pre-attached electrode sheets performs the alignment function before the cell assembly is complete. This preliminary alignment action eliminates the need for subsequent reshaping operations that involve clamping and mechanical stress, thereby preventing powder detachment and short circuit risks while maintaining good electrode alignment.

Inventive Principle:

Principle #10Preliminary action

3Device complexity

If lithium ions cannot be completely intercalated into the negative electrode sheets, then the battery structure is simple, but lithium precipitation occurs reducing cycle life and safety

Engineering Contradiction:

Improvebattery structureVSAvoidcycle life and safety

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The invention replaces mechanical alignment methods (free-fall stacking, reshaping cylinder clamping) with a chemical/structural solution based on the separator's inherent structure. The separator's folded configuration with pre-attached electrodes ensures proper alignment and complete lithium ion intercalation without requiring complex mechanical alignment systems, thereby improving reliability while maintaining structural simplicity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

Improves electrical performance by preventing lithium precipitation, enhancing cycle life and safety, and reducing material costs through precise alignment and optimized material usage.

Implementation Method 1

the separator is folded at the incomplete-cut-off structures

Methodology Applied

Scientific EffectFolding: Folding

Implementation Method 2

thermally compounding the two single-sided electrode sheets on two outermost sides of the laminated units

Methodology Applied

Scientific EffectThermal compounding: Heat Treatment

Data Source

PatentUS20250316769A1Thermal composite laminated cell and method for preparing thermal composite laminated cell

Publication Date: 2025.10.09 EVE POWER CO LTD

AI summary

The disclosure provides a thermal composite laminated cell and a method for preparing the thermal composite laminated cell. The thermal composite laminated cell includes N negative electrode sheets, M positive electrode sheets, and a separator, N is greater than M, and a value of a difference between N and M is 1; the separator includes a plurality of body parts and bending parts alternately and continuously arranged; the negative electrode sheets and the positive electrode sheets are alternately stacked in a thickness direction of the negative electrode sheets, adjacent one of the negative electrode sheets and one of the positive electrode sheets are separated by one of the body parts, the bending parts are provided with incomplete-cut-off structures, and the separator is folded at the incomplete-cut-off structures; two outermost negative electrode sheets are single-sided electrode sheets, and other negative electrode sheets are double-sided electrode sheets.