Flexible Battery Current Collector Layout for Repeated Bending

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Solution Overview

Problem

Conventional secondary batteries are inflexible, pose safety risks due to potential short circuits and damage when bent, and occupy significant space in portable devices, limiting their integration in wearable and compact electronic devices.

Innovation Solution

A battery design featuring overlapping first and second current collectors with insulating fixing members, allowing for repeated bending and stress relief, while maintaining high capacity per unit volume through a film-like exterior body and specific folding techniques.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional secondary battery uses a hard exterior body for safety, then safety is improved, but flexibility and adaptability are worsened

Engineering Contradiction:

ImprovesafetyVSAvoidflexibility

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The battery structure is segmented into multiple functional layers: exterior body, cushioning member, electrode assembly, and sealing member. Each layer performs a specific function, with the cushioning member specifically designed to absorb stress during bending while the exterior body provides safety protection. This segmentation allows the battery to achieve both safety and flexibility simultaneously.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The battery employs a composite structure combining a hard exterior body (for safety and protection) with a soft cushioning member (for flexibility and stress absorption). This composite design allows the battery to maintain structural integrity and safety while enabling repeated bending and shape changes, resolving the contradiction between safety and flexibility.

Inventive Principle:

Principle #40Composite materials

2Quantity of substance

If a conventional secondary battery is designed for high capacity, then energy storage is improved, but volume and device size are worsened

Engineering Contradiction:

ImprovecapacityVSAvoidvolume

Core Design Contradiction:

Quantity of substanceVSVolume of moving object

Solution Approach 1:

The electrode assembly is nested within the exterior body, with the cushioning member and sealing member arranged in concentric layers. This nested structure maximizes the use of internal space, allowing high-capacity electrodes to be packed efficiently without increasing the overall battery volume, thus achieving high capacity per unit volume.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The battery utilizes a three-dimensional stacked arrangement of electrode layers, transitioning from traditional planar designs to vertical stacking. This dimensional change increases the electrode surface area and active material volume within the same footprint, significantly improving capacity per unit volume and enabling compact device integration.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Adaptability or versatility

If a conventional secondary battery is bent repeatedly, then adaptability is improved, but reliability is worsened due to short circuit and damage risks

Engineering Contradiction:

ImprovebendabilityVSAvoidsafety

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

A cushioning member is pre-installed between the electrode assembly and the exterior body to absorb and distribute mechanical stress before it reaches the electrodes. This cushioning layer prevents direct contact and potential short circuits between electrodes during bending, maintaining reliability while enabling repeated flexing and shape changes.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

4Adaptability or versatility

If a battery uses a film-like exterior body for flexibility, then adaptability is improved, but safety is worsened due to heat generation and fire risks

Engineering Contradiction:

ImproveflexibilityVSAvoidsafety

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The battery combines a flexible film-like exterior body with a hard cushioning member and sealing structures. The film-like exterior provides flexibility and conformability, while the cushioning member and sealing layers provide mechanical strength, thermal management, and safety protection, creating a composite structure that achieves both flexibility and safety.

Inventive Principle:

Principle #40Composite materials

Data Source

PatentUS12573723B2Battery and manufacturing method of the same

Publication Date: 2026.03.10 SEMICON ENERGY LAB CO LTD

AI summary

To provide a battery capable of changing in shape safely. To provide a battery capable of repeatedly bent. The battery includes a first lead, a second lead, a first current collector, and a second current collector. The first current collector includes a first portion bonded to the first lead and a second portion coated with a first active material. The second current collector includes a third portion bonded to the second lead and a fourth portion coated with a second active material. The first lead, the second portion, and the fourth portion overlap with each other in a portion. The second lead, the second portion, and the fourth portion overlap with each other in a portion.