Assembled Battery Elastomeric Pressure Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional assembled batteries face pressure fluctuations due to deterioration of constraining members over time, especially under dynamic temperature variations and vibrations, leading to reduced battery performance.
Innovation Solution
The assembled battery design features a spring constant of the electrode body in the array direction of 10,000 kgf/mm or less, achieved by optimizing the porosity of the positive and negative electrode active material layers and incorporating electrically conductive materials, ensuring stable pressure maintenance across cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If end plates are tightened to apply pressure to cells, then appropriate pressure is applied to each cell at manufacturing, but pressure fluctuates over time due to deterioration of constraining members
Solution Approach 1:
The patent replaces static constraining members (end plates and tightening mechanisms) with a dynamic element - the elastomeric material surrounding each cell. This elastomeric material can dynamically adapt to changes in cell dimensions due to expansion/contraction during charge-discharge cycles and temperature variations, automatically maintaining appropriate pressure without deterioration over time.
Solution Approach 2:
The elastomeric material serves itself by inherently providing the constraining function through its elastic properties. Each cell is independently surrounded by elastomeric material that automatically adjusts to maintain pressure, eliminating the need for separate constraining members that can deteriorate. The system uses the natural elastic recovery of the material to self-regulate pressure.
2Strength
If cells are constrained with rigid end plates, then pressure is applied to maintain electron conductivity, but the constraining members deteriorate under temperature variations and vibrations
Solution Approach 1:
The patent changes the key parameter of the constraining member from rigid (end plates) to elastomeric (flexible material). This parameter change allows the constraining element to accommodate temperature variations and vibrations without deteriorating, while still maintaining the necessary compressive force on the cell to ensure proper contact and electron conductivity.
Solution Approach 2:
The patent employs elastomeric material as a flexible shell surrounding each cell. This flexible material can deform elastically in response to temperature changes and mechanical vibrations, preventing deterioration while continuously maintaining the required pressure on the cell terminals and electrode contacts.
3Stability of the object's composition
If the spring constant of the electrode body is high, then structural stability is maintained, but pressure applied to the cell fluctuates when cell laminate length varies
Solution Approach 1:
The patent uses a composite approach where the elastomeric material (with specific elastic properties) combines the structural support function with the pressure application function. The elastomeric material acts as a compliant interface between the rigid cell laminate structure and the cell terminals, absorbing dimensional variations while maintaining stable pressure through its controlled elastic deformation characteristics.
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
This configuration effectively maintains pressure on each cell, enhancing battery performance and durability, particularly in vehicles, by minimizing pressure fluctuations caused by temperature changes and vibrations.
Implementation Method 1
an outer peripheral surface of the battery cell is surrounded by elastomeric material having a predetermined elasticity
Implementation Method 2
a load is applied to the cells in an array direction
Data Source
AI summary
An assembled battery (10) according to the present invention is constructed by connecting a plurality of chargeable and dischargeable cells (12) in series, this assembled battery (10) including a plurality of cells (12), each cell (12) including a flat-shaped electrode body (80) which has a positive electrode and a negative electrode and a container (14) which houses the electrode body (80) and an electrolyte, wherein the plurality of cells (12) are constrained in a state where the cells (12) are aligned so that flat surfaces of the electrode bodies (80) oppose each other and a load is applied to the cells (12) in an array direction, and a spring constant of the electrode body (80) in the array direction in each of the constrained cells (12) is 10,000 kgf/mm or less.