Elastic Bus Bar Thermal Expansion Compensation
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Solution Overview
Problem
The existing electricity storage modules face issues with stress generation at welding points due to thermal expansion differences between polybutylene terephthalate (PBT) side plates and copper conductive members, leading to increased weight and cost, particularly when metal plates are used to suppress deformation.
Innovation Solution
The module incorporates bus bars with elastically deformable bending parts that connect adjacent battery cells, allowing for thermal expansion compensation without the need for a metal case, thereby reducing stress and weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If metal plates are used to suppress deformation, then structural stability is improved, but weight and cost increase
Solution Approach 1:
The patent applies this principle by using a resin material housing instead of rigid metal plates. The resin housing provides sufficient structural stability while being lighter and more cost-effective. The housing maintains its shape and provides stable support for the battery cells without requiring heavy metal reinforcement.
Solution Approach 2:
The patent changes the material parameter from metal to resin, which has different mechanical and thermal properties. This parameter change allows the housing to achieve the required structural stability with reduced weight and cost, while also providing better thermal expansion compatibility with the battery components.
2Stability of the object's composition
If metal plates are used to suppress deformation, then structural stability is improved, but cost increases
Solution Approach 1:
The patent replaces expensive metal plates with a resin material housing that achieves the required structural stability at lower cost. The resin housing can be manufactured using molding processes, which are generally more cost-effective than metal fabrication processes.
Solution Approach 2:
The patent uses composite material construction with resin as the primary material and incorporates reinforcement structures (such as ribs or strengthened sections) to achieve the required structural stability without using solid metal plates, thereby reducing cost while maintaining performance.
3Reliability
If PBT side plates and copper conductive members are used, then electrical connection is achieved, but stress generation occurs due to thermal expansion differences
Solution Approach 1:
The patent changes the housing material parameter from PBT to a resin material with thermal expansion characteristics closer to copper. This parameter change reduces the thermal expansion difference between the housing and copper conductive members, thereby minimizing stress generation at welding points during temperature variations.
Solution Approach 2:
The patent selects a resin material whose thermal expansion properties are more homogeneous or compatible with copper compared to PBT. This reduces the heterogeneity in thermal behavior between different materials in the assembly, preventing differential expansion and contraction that causes stress.
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 effectively relaxes stress at welding points, reduces material costs, and maintains electrical performance by using copper bus bars with PBT holding cases, achieving efficient thermal expansion management without additional metal enclosures.
Implementation Method 1
a bending part (458) that is elastically deformable
Implementation Method 2
stress in a welding point generated due to thermal change
Data Source
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AI summary
An electricity storage module in which a plurality of battery cells are electrically connected via conductive members, wherein: each of the conductive members has a pair of electrode connecting parts that are welded to respective electrode terminals of a pair of adjacent battery cells, a base part that is connected to the pair of electrode connecting parts via a pair of elastically deformable parts, and a voltage detecting terminal that is connected to the base part and detects a terminal voltage of a battery cell.