Laminated Battery Fused Edge Geometry to Curb Bent-Part Spring-Back

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Solution Overview

Problem

Laminated batteries face structural efficiency reduction due to spring-back in bent parts, causing the angle to exceed 90° and increasing the battery's outer size and decreasing volume efficiency.

Innovation Solution

A laminated battery design featuring a fused laminate film package with an acute angle bent part bent to less than 90°, including a leading end side region redirected away from the bending direction, and a method using a rotating fulcrum roll member with a protrusion to form the acute angle bent part, reducing spring-back and maintaining structural efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the fused part is bent to form an angle of 90° or less to improve structural efficiency, then the outer size of the battery is reduced, but spring-back occurs causing the angle to exceed 90° and volume efficiency decreases

Engineering Contradiction:

Improvebattery outer sizeVSAvoidbent part angle stability

Core Design Contradiction:

Volume of moving objectVSStability of the object's composition

Solution Approach 1:

The patent applies preliminary action by forming the acute angle bent part during the bending process with the understanding that spring-back will occur. The bending is designed to create an acute angle (less than 90°) that, after spring-back, will still maintain the desired compact configuration. The leading end side region is pre-configured to be redirected away from the bending direction to compensate for the anticipated spring-back effect.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent applies preliminary anti-action by designing the leading end side region to be redirected away from the bending direction. This redirection creates a counteracting geometric configuration that prevents the bent part from springing back to form an angle greater than 90°. The redirected leading end side region effectively counterbalances the spring-back force by providing a geometric constraint that maintains the acute angle configuration.

Inventive Principle:

Principle #9Preliminary anti-action

2Volume of moving object

If the fused part is bent to form an acute angle to reduce battery size, then volume efficiency is improved, but the structural integrity may be compromised due to stress concentration

Engineering Contradiction:

Improvebattery volume efficiencyVSAvoidfused part structural integrity

Core Design Contradiction:

Volume of moving objectVSStrength

Solution Approach 1:

The patent applies spheroidality by forming the acute angle bent part with a curved configuration rather than a sharp angular bend. The arcuate shape of the bent part distributes stress more evenly along the curve, reducing stress concentration at the bend location. This curved configuration maintains structural integrity while achieving the compact acute angle geometry needed for improved volume efficiency.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent applies local quality by creating a redirected leading end side region with specific geometric properties different from the rest of the fused part. This redirected region has altered orientation and shape characteristics that specifically address the stress distribution and structural integrity requirements at the critical bent part location, while the rest of the laminate film package maintains its standard configuration.

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

The solution effectively curbs the reduction in structural efficiency by maintaining the acute angle bent part at less than 90°, preventing spring-back and enhancing volume efficiency without increasing the battery's size.

Implementation Method 1

a heat treatment unit that performs heat treatment on the laminated battery

Methodology Applied

Scientific EffectHeating: Heating

Implementation Method 2

the laminate film package has a fused part at which an end part of the first laminate film portion and an end part of the second laminate film portion are overlaid and inner surfaces thereof are fused together

Methodology Applied

Scientific EffectFusion:

Implementation Method 3

a bending process of pressing a rotating fulcrum roll member having a disc shape against the fused part and bending the fused part to form an angle of less than 90°

Methodology Applied

Scientific EffectMechanical Force: Mechanical Force

Implementation Method 4

the fulcrum roll member having a protrusion disposed in a circumferential direction at an outer peripheral part of the disc shape on a side that contacts the fused part

Methodology Applied

Scientific EffectForce Concentration:

Data Source

PatentUS20250007049A1Laminated battery and method of producing laminated battery

Publication Date: 2025.01.02 TOYOTA JIDOSHA KK

AI summary

A laminated battery includes: an electrode body; and a laminate film package that covers the electrode body and encloses the electrode body therein. In the laminated battery, the laminate film package includes a first laminate film portion and a second laminate film portion, and the laminate film package has a fused part at which an end part of the first laminate film portion and an end part of the second laminate film portion are overlaid and inner surfaces thereof are fused together. The fused part has an acute angle bent part that is bent in an angular shape or an arcuate shape to form an angle of less than 90°, and includes, in a region further toward a leading end of the fused part than the acute angle bent part, a leading end side region that is redirected away from a direction of bending in the acute angle bent part.