Hybrid Compression Pad Structure for Battery Cell Swelling
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Solution Overview
Problem
Existing compression pads for battery cell modules face a conflict between achieving high prestressing forces and maintaining compressibility throughout the life of a vehicle, with foamed elastomers offering high compressibility but limited prestressing, while solid elastomers provide higher forces but limited compressibility due to their non-porous nature.
Innovation Solution
Combining two materials with different mechanical properties, such as a solid elastomer and a foamed elastomer, where the solid elastomer is surrounded by the foamed material to allow transverse expansion and adjust the overall stiffness of the compression pad, enabling both high prestressing and compressibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If foamed elastomers are used for compression pads, then compressibility is improved, but prestressing force is reduced
Solution Approach 1:
The patent applies composite materials by combining two different elastomeric materials with distinct compressive strengths within a single compression pad. The first elastomeric material (higher compressive strength) and second elastomeric material (lower compressive strength) are integrated to create a composite structure that simultaneously provides both high prestressing force and high compressibility. This resolves the contradiction by allowing the harder material to contribute force while the softer material contributes compressibility.
Solution Approach 2:
The patent implements local quality by assigning different material properties to different regions or portions of the compression pad. Specifically, the first elastomeric material with higher compressive strength is placed in regions where prestressing force is needed, while the second elastomeric material with lower compressive strength is placed in regions where compressibility is prioritized. This spatial differentiation allows each material to optimize its function locally.
2Force
If solid elastomers are used for compression pads, then prestressing force is improved, but compressibility is reduced
Solution Approach 1:
The patent uses composite materials to overcome the limitations of solid elastomers. By integrating the first elastomeric material (solid-like, higher compressive strength) with the second elastomeric material (foam-like, lower compressive strength), the composite structure achieves both the high prestressing force of solid elastomers and the high compressibility of foamed elastomers, eliminating the need to choose between the two.
Solution Approach 2:
The patent applies local quality by strategically positioning the solid-like first elastomeric material in areas requiring high force transmission while placing the foam-like second elastomeric material in areas requiring compression accommodation. This localized material assignment allows the compression pad to exhibit both high force capability and high compressibility in different regions.
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 allows for optimized compression pad properties that balance prestressing forces with compressibility, effectively managing volume changes in battery cells over the vehicle's life, enhancing cycle stability and longevity.
Implementation Method 1
A second material, e.g. a foam, such as elastomeric foam, represents a material at least partially surrounding the at least one volume of the first material... allowing for a transverse expansion of the elastomer
Implementation Method 2
For increased cycle stability and longevity of the cells, they are strained with the compression pads. The prestressing is realized via pre-compression of the compression pads in the battery module. In addition, volume changes resulting from the so-called swelling can be balanced using the compressible compression pads.
Data Source
AI summary
A compression pad is provided for a battery cell stack. The compression pad includes a first material having a first compressive strength; a second material having a second compressive strength that is different than the first compressive strength. The compression pad includes at least one volume of the first material, which is at least partially surrounded by the second material with or without direct contact thereto. Furthermore, there is provided a method for manufacturing a compression pad, as well as a battery cell stack constructed on the basis of the compression pad.