Solid-State Battery Elastic Sheet for Stress Relief and Fire Safety

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Solution Overview

Problem

Commercially available rechargeable lithium batteries using electrolyte solutions are prone to safety issues such as explosions due to flammability, and all-solid-state batteries face stress-related cracks and non-uniform pressing that affect discharge efficiency and cycle-life characteristics.

Innovation Solution

Incorporating an elastic sheet with an extinguishing capsule between the unit cells of an all-solid-state rechargeable battery structure to alleviate stress and ensure fire safety, using a polymer-based elastic sheet that includes an extinguishing capsule to prevent ignition and explosion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a rigid structure is used for all-solid-state battery, then manufacturing precision is improved, but stress concentration causes cracks and reduces cycle-life

Engineering Contradiction:

Improvepressing uniformityVSAvoidcycle-life characteristics

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent introduces an elastic sheet as a flexible component between unit cells and at outermost ends. This elastic sheet absorbs stress during charging/discharging cycles and prevents stress concentration that would cause cracks in the solid electrolyte, thereby improving cycle-life while maintaining manufacturing precision through controlled elasticity.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The elastic sheet is positioned in advance at strategic locations (between unit cells and at outermost ends) to cushion against future stress accumulation. This pre-positioned cushioning prevents cracks before they occur during repeated charging and discharging, resolving the contradiction between rigid structure precision and long-term reliability.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Reliability

If elastic sheet is added to relieve stress, then cycle-life characteristics are improved, but device complexity increases

Engineering Contradiction:

Improvecycle-life characteristicsVSAvoidbattery structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Instead of making the entire battery structure elastic, the patent applies elastic sheets only at specific critical locations: between unit cells where stress concentrates and at outermost ends where impact occurs. This localized application improves cycle-life without adding complexity to the entire device structure.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The elastic sheet serves as an intermediary component between the rigid unit cells. It mediates the stress transmission, absorbing excessive force while maintaining structural integrity. This simple intermediary element resolves the complexity issue by providing a straightforward mechanical solution rather than redesigning the entire battery architecture.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If fire safety measures are added, then safety is improved, but manufacturing complexity increases

Engineering Contradiction:

Improvefire safetyVSAvoidmanufacturing process simplicity

Core Design Contradiction:

Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The patent combines the fire safety function with the existing elastic sheet structure by incorporating extinguishing capsules into the elastic sheet. This merging of functions means the same component that relieves stress also provides fire safety, eliminating the need for separate fire suppression systems and maintaining manufacturing simplicity.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The elastic sheet is designed with multi-functionality: it serves both as a stress-relieving mechanical component and as a fire safety device through embedded extinguishing capsules. This universal design improves safety without increasing manufacturing complexity, as one component performs multiple protective functions.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 elastic sheet with an extinguishing capsule effectively relieves stress during manufacturing and charging/discharging, improving cycle-life characteristics and ensuring fire safety without impairing battery performance.

Implementation Method 1

applying an elastic sheet that can sufficiently relieve stress transmitted during the pressurizing process in the manufacture of an all-solid-state rechargeable battery and stress generated by changes in the thickness of the battery during repeated charging and discharging

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

at least one of the elastic sheets include an extinguishing capsule

Methodology Applied

Scientific EffectFire suppression:

Data Source

PatentUS20250381431A1All-solid-state rechargeable battery structure

Publication Date: 2025.12.18 SAMSUNG SDI CO LTD

AI summary

The present invention relates to an all-solid-state rechargeable battery structure, including two or more unit cells including a positive electrode, a negative electrode, and a solid electrolyte layer between the positive electrode and the negative electrode, and elastic sheets located between and at the outermost end of the unit cells, wherein at least one of the elastic sheets includes an extinguishing capsule.