Compressible Partition Battery Module Stress Management
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Solution Overview
Problem
Battery modules experience cycle performance degradation due to stress and volume expansion of electrode plates during charge-discharge cycles, leading to reduced permeability of electrolyte and potential safety issues.
Innovation Solution
A battery module design incorporating a compressible partition between adjacent batteries, with a coefficient of compressibility ≤2 MPa, which acts as a buffer to manage expansion and stress, maintaining electrolyte permeability and preventing excessive expansion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If no partition is arranged between adjacent batteries, then the structure is simple and manufacturing is easy, but the electrode plate expansion causes stress and distortion of battery core, degrading cycle performance
Solution Approach 1:
The battery module is segmented into independent battery units by inserting partitions between adjacent batteries. Each partition creates a separate compartment that independently manages the expansion and contraction of individual batteries during charge-discharge cycles, preventing stress transmission and core distortion while maintaining manufacturing feasibility through modular assembly
Solution Approach 2:
The partition acts as an intermediary element between adjacent batteries, providing a buffer zone that absorbs expansion forces and prevents direct contact between battery casings. This mediator structure allows each battery to expand and contract independently without causing stress or distortion to neighboring units, thereby preserving cycle performance
2Stability of the object's composition
If a rigid partition is used between batteries, then the structural stability is high, but the electrode plate expansion causes increased stress and reduced electrolyte permeability, degrading cycle performance
Solution Approach 1:
The partition's physical parameters are optimized to achieve the right balance: its thickness is controlled within 5-20mm and material density is adjusted to provide appropriate flexibility. This parameter optimization allows the partition to maintain structural stability for spacing and alignment while possessing sufficient compressibility to accommodate electrode plate expansion without excessive stress generation or electrolyte permeability reduction
3Stability of the object's composition
If the partition thickness is increased to prevent battery expansion, then the structural stability is improved, but the manufacturing cost increases and the partition cannot effectively buffer expansion stress
Solution Approach 1:
The partition thickness is optimized within the range of 5-20mm based on empirical data and theoretical calculations. This optimized thickness provides sufficient structural stability for maintaining battery spacing and alignment while remaining thin enough to effectively buffer expansion stress and control manufacturing costs, avoiding the need for excessively thick partitions
4Reliability
If the partition is made highly compressible to buffer expansion, then the stress release is improved, but the structural stability decreases and batteries may shift position
Solution Approach 1:
The partition's material properties and geometric parameters are precisely controlled to achieve optimal compressibility within specific ranges. The thickness of 5-20mm and selected material density provide sufficient compressibility to buffer expansion stress and release pressure, while maintaining adequate structural stability to prevent battery shifting and maintain proper spacing during operation
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 enhances cycle performance and safety by reducing stress and volume expansion, ensuring sufficient electrolyte permeability and preventing short circuits, while maintaining structural stability and thermal insulation.
Implementation Method 1
the partition has a compressibility and a coefficient of compressibility δ1 at a pressure equal to or smaller than 2 MPa
Implementation Method 2
the partition can prevent further expansion of the battery, thereby effectively restricting the stress within the battery cells
Data Source
AI summary
The disclosure provides a battery module. The battery module comprises: a frame having an accommodation space; and a plurality of batteries successively arranged in the accommodation space in a thickness direction of the battery, wherein a partition is arranged between adjacent batteries, wherein the partition has a compressibility and a coefficient of compressibility δ1 at a pressure equal to or smaller than 2 MPa, which meets a relation C0×δ1≤A0×0.2, wherein C0 is an initial thickness of the partition, and A0 is an initial thickness of the battery.