Battery Cell Housing Structure for Pressure Relief Rupture Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The pressure relief parts on battery cells are prone to rupture due to the expansion and deformation of the electrode assembly, leading to reduced reliability and increased risk of liquid leakage.
Innovation Solution
The battery cell design includes a first wall part with a greater thickness than the second wall part, with a pressure relief part integrated into the first wall part, enhancing the strength of the first wall part and reducing the risk of rupture, while allowing for efficient manufacturing through stamping processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pressure relief part is disposed on the housing, then the battery cell can release pressure when needed, but the pressure relief part is prone to rupture due to electrode assembly expansion and deformation
Solution Approach 1:
The patent applies local quality by making the first wall part (where the pressure relief part is disposed) thicker than the second wall part. This localized thickness enhancement provides additional structural support and strength specifically at the pressure relief part, reducing its susceptibility to rupture during electrode assembly expansion while maintaining overall housing functionality.
2Strength
If the thickness of the first wall part is increased to enhance strength, then the reliability improves, but the manufacturing complexity increases
Solution Approach 1:
The patent employs parameter changes by specifying different thickness values for different wall parts (E1 for the first wall part, D1 for the second wall part, where E1 > D1). This parameter differentiation allows the first wall part to have enhanced strength where needed while keeping other parts simpler, and the patent explicitly states that the housing can be manufactured by stamping a plate with uniform thickness equal to E1, making the manufacturing process feasible.
3Reliability
If the thickness dimension E1 is increased to reduce rupture probability, then the reliability improves, but the volumetric energy density decreases
Solution Approach 1:
The patent applies local quality by increasing the thickness only of the first wall part (where the pressure relief part is located) while keeping the second wall parts thinner. This localized approach provides the necessary structural support and reliability at the critical pressure relief location without significantly increasing the overall housing volume, thereby minimizing the impact on volumetric energy density.
Solution Approach 2:
The patent uses partial action by enhancing the thickness only where specifically needed (the first wall part with the pressure relief part) rather than uniformly increasing the thickness of the entire housing. This partial enhancement achieves the reliability improvement at the critical location while avoiding unnecessary material usage and volume increase elsewhere.
Data Source
AI summary
A battery cell comprises: an electrode assembly, at least one positive electrode sheet and at least one negative electrode sheet, wherein the positive electrode sheet and the negative electrode sheet are stacked to form a straight area, and at least part of the positive electrode sheet and at least part of the negative electrode sheet are stacked in a first direction in the straight area; and a casing comprising a first wall portion provided with a pressure relief portion and two second wall portions, the two second wall portions being respectively located on two sides of the straight area in the first direction, and the first wall portion being located on a side of the electrode assembly in a second direction. The thickness of the first wall portion in the second direction is greater than the thickness of the second wall portions in the first direction.