Laminated Battery Compression Layout for Uniform Cell Capacity

Solution Overview

Problem

Laminated batteries suffer from reliability issues due to variations in battery capacity and current flow, leading to over-charge, over-discharge, and local heat generation, particularly in series- and parallel-connected configurations.

Innovation Solution

A manufacturing method for laminated batteries involves laminating unit cells with varying degrees of compression, where cells at both ends are compressed less than those in the center, and applying differential compressive forces to minimize capacity and compression variations, ensuring uniformity and reducing unsafe events.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If uniform compression is applied to all unit battery cells, then manufacturing simplicity is maintained, but variations in degree of compression cause variations in battery capacity and reliability

Engineering Contradiction:

Improvebattery reliabilityVSAvoidcompression arrangement complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies different compression degrees to different locations of unit battery cells. Specifically, cells at both ends in the laminating direction are compressed to a first degree, while cells in the middle are compressed to a second degree that is higher than the first degree. This local differentiation compensates for the non-uniform pressure distribution during collective compression, ensuring uniform final compression across all cells and improving battery reliability.

Inventive Principle:

Principle #3Local quality

2Productivity

If collective compression is applied to all laminated unit battery cells, then manufacturing efficiency is improved, but non-uniform pressure distribution causes variations in degree of compression and battery capacity

Engineering Contradiction:

Improvemanufacturing efficiencyVSAvoidcompression uniformity

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent performs preliminary individual compression on each unit battery cell before laminating them together. This preliminary action pre-compresses each cell to a specific degree, so that when collective compression is applied to the laminated assembly, the final compression uniformity is achieved. This preliminary preparation enables efficient collective compression while maintaining precise compression control.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent applies different compression degrees to different locations of unit battery cells. Specifically, cells at both ends in the laminating direction are compressed to a first degree, while cells in the middle are compressed to a second degree that is higher than the first degree. This local differentiation compensates for the non-uniform pressure distribution during collective compression, ensuring uniform final compression across all cells and improving battery reliability.

Inventive Principle:

Principle #3Local quality

3Reliability

If variations in battery capacity are reduced, then over-charge and over-discharge are prevented, but manufacturing complexity increases

Engineering Contradiction:

Improvebattery safetyVSAvoidcompression control complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies different compression degrees to different locations of unit battery cells. Specifically, cells at both ends in the laminating direction are compressed to a first degree, while cells in the middle are compressed to a second degree that is higher than the first degree. This local differentiation compensates for the non-uniform pressure distribution during collective compression, ensuring uniform final compression across all cells and improving battery reliability.

Inventive Principle:

Principle #3Local quality

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 approach enhances the reliability of laminated batteries by preventing over-charge, over-discharge, and local heat generation, improving safety and performance through reduced variations in battery capacity and current flow.

Implementation Method 1

a solid electrolyte layer located between the negative-electrode layer and the positive-electrode layer

Methodology Applied

Scientific EffectIon transport: Ion Exchange

Implementation Method 2

collectively compressing, in a direction of laminating, the plurality of unit cells laminated in the laminating

Methodology Applied

Scientific EffectCompression: Compression

Data Source

PatentUS12531275B2Method for manufacturing laminated battery

Publication Date: 2026.01.20 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

AI summary

A method for manufacturing a laminated battery is a method for manufacturing a laminated battery in which a plurality of unit battery cells each having a negative-electrode layer, a positive-electrode layer are laminated, and a solid electrolyte layer located between the negative-electrode layer and the positive-electrode layer. The method includes laminating the plurality of unit battery cells and collectively compressing, in a direction of laminating, the plurality of unit cells laminated in the laminating. In the laminating, the plurality of unit battery cells are laminated in such an arrangement that two unit battery cells located at both ends in the direction of laminating are both lower in degree of compression than a unit battery cell located between the two unit battery cells.