Profiled Pressure Equalizer for Swelling Pouch Cell Cooling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Rechargeable battery packs face mechanical stresses and potential damage due to swelling of pouch cells, which restricts convection and can lead to overheating, especially in lithium-polymer cells, as existing solutions do not effectively manage the increased volume and resulting pressure.
Innovation Solution
A deformable pressure equalizing element with a profiled surface, such as trapezoidal or honeycomb-like, is used to allow convection currents along the pouch cell, even during swelling, by maintaining open volumes that enable cooling through forced or free convection, and is made from materials like elastomers with higher elasticity than the pouch cells, potentially incorporating phase-change materials for temperature regulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If continuously solid pressure equalizing elements are used to delimit pouch cells, then mechanical protection is provided, but convection cooling is blocked when cells swell
Solution Approach 1:
The pressure equalizing element is designed with a porous structure containing numerous through-going channels that extend through its thickness. This porous configuration allows convection cooling air to pass through the element and reach the pouch cell surface, while the element maintains its mechanical protective function. The channels ensure that even when pouch cells swell, the cooling pathways remain open.
Solution Approach 2:
The pressure equalizing element combines structural rigidity for mechanical protection with a porous network for thermal management. This composite structure integrates both protective and cooling functions into a single component, resolving the contradiction between mechanical strength and convective heat dissipation.
2Adaptability or versatility
If pouch cells are allowed to swell freely, then cell aging is accommodated, but mechanical stresses and housing damage occur
Solution Approach 1:
The pressure equalizing element functions as a flexible yet structurally stable component that can deform elastically to accommodate pouch cell swelling. Its porous structure allows it to yield to volume increases while maintaining overall structural integrity, preventing stress concentration and housing damage.
Solution Approach 2:
The pressure equalizing element acts as a pre-positioned cushioning structure between the pouch cell and housing. It absorbs and distributes mechanical stresses generated during swelling, protecting both the cell and housing from damage before critical stress levels are reached.
3Stability of the object's composition
If the pressure equalizing element is made solid and continuous, then structural integrity is maintained, but cooling convection paths are blocked
Solution Approach 1:
The pressure equalizing element employs a porous structure with numerous through-going channels that maintain structural integrity while providing continuous convection pathways. The channel network preserves the element's mechanical stability while enabling unrestricted airflow for cooling the pouch cell.
4Ease of manufacture
If conventional pressure equalizing elements are used, then manufacturing is simplified, but operational safety during swelling is compromised
Solution Approach 1:
The porous pressure equalizing element can be manufactured using established techniques while providing superior operational safety. The through-going channel structure ensures continuous cooling pathways during cell swelling, preventing overheating and improving reliability without significantly complicating the manufacturing process.
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 solution ensures continuous convection cooling, preventing mechanical stress and damage, allowing the battery pack to maintain operational safety and efficiency even during pouch cell swelling, while maintaining a compact design and supporting high current consumption.
Implementation Method 1
a deformable pressure equalizing element is arranged parallel to the pouch cell in such a way that the pressure equalizing element can yield to an increase in volume of the pouch cell
Implementation Method 2
the pressure equalizing element is profiled so that a convection current can pass along the pouch cell in spite of the increase in volume of the pouch cell
Implementation Method 3
The pressure equalizing element can have a material elasticity that is greater than a cell elasticity of the pouch cells... potentially incorporating phase-change materials for temperature regulation
Data Source
AI summary
A rechargeable battery pack for an electric hand-held power tool, wherein the rechargeable battery pack has a housing with at least one pouch cell arranged therein, wherein a deformable pressure equalizing element is arranged parallel to the pouch cell in such a way that the pressure equalizing element can yield to an increase in volume of the pouch cell, wherein the pressure equalizing element is profiled, so that a convection current can pass along the pouch cell in spite of the increase in volume of the pouch cell.