Battery Cell Pressure Relief Structure for Housing Deformation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Battery cell housings deform under expansion, causing damage to pressure relief parts due to tensile forces, leading to reduced reliability and normal operation.
Innovation Solution
The battery cell design includes a pressure relief part with a body part between a weak part and a first wall part, where the body part's thickness is less than the wall part's, reducing the tensile force on the weak part and enhancing deformation resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pressure relief part is disposed on the first wall part, then the pressure relief function is achieved, but the tensile force from housing deformation causes damage to the pressure relief part
Solution Approach 1:
The pressure relief part is divided into three segments: the first wall part (D1), the body part (D2), and the weak part (D3). This segmentation allows each part to have different thickness characteristics, enabling the structure to both withstand tensile forces during normal use and fail safely when pressure relief is needed.
Solution Approach 2:
Different parts of the pressure relief structure have different local qualities in terms of thickness. The first wall part has maximum thickness (D1) for strength, the body part has intermediate thickness (D2) for buffering, and the weak part has minimum thickness (D3) for controlled failure. This local quality differentiation resolves the contradiction between needing strength to resist tensile forces and needing weakness to enable pressure relief.
2Reliability
If the weak part thickness is reduced to enable smooth opening during thermal runaway, then the pressure relief function is improved, but the risk of fracture during normal use increases
Solution Approach 1:
The body part serves as an intermediary between the first wall part and the weak part. With thickness D2 satisfying D3 < D2 < D1, the body part buffers the tensile forces transmitted from the wall to the weak part, reducing the stress concentration on the weak part while still allowing it to fail when pressure exceeds the relief threshold.
Solution Approach 2:
The body part provides beforehand cushioning by absorbing and distributing tensile forces during normal battery operation. This cushioning effect protects the weak part from premature fracture due to housing deformation, while maintaining the weak part's ability to open when thermal runaway occurs and internal pressure exceeds the relief threshold.
Data Source
AI summary
A battery cell, a battery, and an electrical apparatus are disclosed. The battery cell includes an electrode assembly having a positive electrode plate and a negative electrode plate that define a flat area. A housing accommodates the electrode assembly and includes a first wall portion and two second wall portions disposed on either side of the flat area. A pressure relief portion is arranged on the first wall portion and includes a weak portion and a main body portion, with the main body portion positioned between the weak portion and the first wall portion. The maximum thickness of the first wall portion is D1, the minimum thickness of the main body portion is D2, and the maximum thickness of the weak portion is D3, where D3<D2<D1. This structure provides controlled pressure relief while maintaining housing integrity.