Battery Cell Buffer Pad Structure Against Thermal Shrinkage

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Solution Overview

Problem

Lithium-ion batteries experience reduced buffering capacity due to thermal shrinkage of buffer pads during the vacuum baking process, leading to material damage and compromised volume stability during long-term use.

Innovation Solution

Incorporating an elastic buffer pad with a support layer to suppress thermal shrinkage of the elastic buffer layer, enhancing volume stability by balancing compression rates, porosities, and elastic moduli of the buffer and support layers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a buffer pad is used in lithium-ion batteries, then buffering capacity is provided, but thermal shrinkage during vacuum baking reduces buffering capacity

Engineering Contradiction:
Improvebuffering capacityVSAvoidthermal shrinkage
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The buffer pad is constructed as a composite structure comprising a buffer layer and a support layer. The buffer layer (first material) provides buffering capacity while the support layer (second material) resists thermal shrinkage during vacuum baking. This composite structure allows both materials to work together, maintaining both buffering capacity and dimensional stability under thermal conditions.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent specifies controlling the thickness ratio between the buffer layer and support layer, as well as adjusting the compression modulus parameters of both layers. By optimizing these physical parameters, the buffer pad achieves appropriate softness for buffering while the support layer provides sufficient rigidity to prevent excessive thermal shrinkage during the vacuum baking process.

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If buffer pad material is used, then volume stability is needed, but mechanical stress causes material damage during long-term use

Engineering Contradiction:
Improvevolume stabilityVSAvoidmaterial damage
Core Design Contradiction:
Stability of the object's compositionVSStrength

Solution Approach 1:

The composite structure of buffer layer and support layer addresses this contradiction by assigning different functional roles: the buffer layer maintains volume stability through its compressible nature, while the support layer provides mechanical strength and damage resistance. The combination allows the buffer pad to withstand long-term mechanical stress without material failure while maintaining volume stability.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

Different regions of the buffer pad have different material properties optimized for their specific functions. The buffer layer has lower compression modulus for volume stabilization, while the support layer has higher compression modulus for mechanical strength. This local differentiation of material quality allows simultaneous achievement of volume stability and damage resistance.

Inventive Principle:
Principle #3Local quality

3Reliability

If support layer is added to suppress thermal shrinkage, then buffering capacity is maintained, but device complexity increases

Engineering Contradiction:
Improvebuffering capacityVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The buffer pad is constructed as a composite structure comprising a buffer layer and a support layer. The support layer composited with the elastic buffer layer provides support to the elastic buffer layer, suppressing thermal shrinkage during vacuum baking and maintaining buffering capacity. This composite design achieves functional improvement while keeping the structure relatively simple.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The support layer is disposed on at least one side of the buffer layer in the thickness direction, utilizing the dimensional arrangement to provide support without significantly increasing planar complexity. This dimensional configuration allows the support function to be integrated into the existing buffer pad structure with minimal added complexity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 mitigates thermal shrinkage and mechanical stress, maintaining battery volume stability and reducing energy density impact, thereby improving long-term performance.

Implementation Method 1

thermal shrinkage of the elastic buffer layer (such as thermal shrinkage during a vacuum baking process)

Methodology Applied
Scientific EffectThermal shrinkage: Thermal Contraction

Implementation Method 2

alleviating the issue of material damage due to mechanical stress in the later stages of battery use

Methodology Applied
Scientific EffectMechanical stress: Compression

Implementation Method 3

the support layer being configured to support the elastic buffer layer

Methodology Applied
Scientific EffectElastic support: Elasticity

Data Source

PatentEP4679597A1Battery cell, battery and electric device
Publication Date: 2026.01.14 CONTEMPORARY AMPEREX TECHNOLOGY CO LTD
  • EP4679597A1 patent drawingFigure 1~2
  • EP4679597A1 patent drawingFigure 3~6
  • EP4679597A1 patent drawingFigure 7~9

AI summary

The present application discloses a battery cell, a battery, and an electric apparatus. The battery cell includes: a housing; at least one electrode assembly, the electrode assembly being disposed within the housing; at least one elastic buffer pad, the elastic buffer pad including an elastic buffer layer and a support layer disposed on at least one side of the elastic buffer layer, the support layer being configured to support the elastic buffer layer; the elastic buffer pad being disposed between the electrode assembly and the housing, and/or between two adjacent electrode assemblies.