Non-Uniform Battery Pack Case for Cell Swelling Stability
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Solution Overview
Problem
Conventional battery pack cases have uniform thickness, which does not account for the varying swelling of battery cells, leading to potential changes in shape and weight inefficiencies.
Innovation Solution
A battery pack case with nonuniform thickness is designed, where parts facing the swelling surface of battery cells have a larger thickness for rigidity, while other parts have a smaller thickness to reduce weight and increase inner space utilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a battery pack case is manufactured with uniform thickness using a pressing method, then the manufacturing process is simple, but the weight increases and inner space utilization decreases
Solution Approach 1:
The battery pack case is designed with non-uniform thickness where different regions have different thickness values. Specifically, the top plate has a first thickness in regions facing battery cell swelling surfaces and a second thickness (greater than the first) in regions not facing swelling surfaces. This local differentiation allows weight reduction in non-critical areas while maintaining structural integrity where needed.
2Ease of manufacture
If a battery pack case is manufactured with uniform thickness, then manufacturing is easier, but the ability to prevent shape change due to battery swelling is reduced
Solution Approach 1:
The case structure implements different thicknesses at different locations to match the swelling characteristics of battery cells. The thicker regions are positioned at areas not subject to swelling pressure, providing structural support without adding unnecessary weight elsewhere. This localized thickness variation optimizes both shape stability and manufacturing efficiency.
3Productivity
If laser welding is used to couple the top plate to the U-frame, then precise tolerance management is necessary when gaps are generated, but this increases manufacturing complexity
Solution Approach 1:
The thickness parameters of the top plate are specifically designed to accommodate manufacturing tolerances and potential gaps during welding. By adjusting the thickness values and dimensional parameters, the design ensures proper fit and weldability even when slight gaps occur between the top plate and U-frame, reducing the stringency of tolerance requirements.
Data Source
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AI summary
The present invention relates to a battery pack case configured to receive a battery cell stack constituted by a plurality of stacked battery cells therein, the battery pack case including a first case configured to allow the battery cell stack to be mounted therein and a second case coupled to the first case, the second case being configured to cover the battery cell stack, wherein the first case includes a first flat panel portion and a first side portion, the second case includes a second flat panel portion and a second side portion, the thickness of the second flat panel portion of the second case is less than the thickness of the second side portion of the second case, and the first side portion is disposed so as to face a swelling surface of each of the battery cells, whereby it is possible to minimize change in volume of the battery pack case, and therefore it is possible to secure dimensional stability thereof.