Battery Cell Cover Plate Venting for Controlled Pressure Relief
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Solution Overview
Problem
Existing cover plate assemblies in battery cells fail to effectively manage gas pressure relief, leading to premature explosion and safety hazards due to improper sizing of the pressure-relief structure, which can burst open prematurely or result in excessive gas overflow during thermal runaway.
Innovation Solution
A cover plate assembly with a support body featuring a groove designed according to the formula S=K×CT×V, where K is the gas production coefficient, C is the capacity, T is the pressure-relief time, and V is the pressure-relief speed, ensuring a balanced and controlled pressure relief by defining an effective pressure-relief area S, and incorporating a detachable pressure-relief member with a specific groove shape and connection mechanism to prevent premature failure and excessive gas overflow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pressure-relief structure is made larger to relieve gas pressure, then the pressure relief capability is improved, but the cell may explode prematurely due to excessive gas overflow
Solution Approach 1:
The patent applies parameter changes by precisely calculating and controlling the groove area S using the formula S=K×CT×V, where K is the gas production coefficient, C is the capacity, T is the pressure-relief time, and V is the pressure-relief speed. This quantitative approach transforms the pressure-relief structure from a qualitative design to a precisely controlled parameter-based design, ensuring the groove area is exactly sufficient to relieve pressure without causing excessive gas overflow.
2Strength
If the pressure-relief structure is made smaller to prevent premature explosion, then the structural integrity is improved, but the pressure relief effectiveness deteriorates during thermal runaway
Solution Approach 1:
The patent resolves this contradiction by using the formula S=K×CT×V to calculate the optimal groove area that precisely balances structural integrity and pressure relief effectiveness. The calculated area S ensures the groove is large enough to relieve pressure effectively during thermal runaway but not so large as to cause premature explosion, achieving both structural strength and reliability simultaneously.
3Speed
If the groove area is increased to improve pressure relief speed, then the pressure-relief time is reduced, but the gas production exceeds the relief capacity causing premature failure
Solution Approach 1:
The patent applies parameter changes by using the formula S=K×CT×V to establish the precise relationship between groove area S, pressure-relief speed V, and pressure-relief time T. This ensures the groove area is optimized to match the gas production rate K×C, achieving adequate pressure relief speed without causing premature failure due to gas accumulation.
4Object-generated harmful factors
If the groove area is decreased to prevent excessive gas overflow, then the safety is improved, but the pressure relief time increases leading to delayed response during thermal runaway
Solution Approach 1:
The patent resolves this contradiction by calculating the optimal groove area S using the formula S=K×CT×V, which balances gas overflow control with pressure relief time. The formula ensures the groove area is sufficient to relieve pressure within an appropriate time frame T while preventing excessive gas overflow, achieving both safety and timely response during thermal runaway events.
Data Source
AI summary
A cell includes a housing, an electrode core and a cover plate assembly. The electrode core is disposed within the housing, and the cover plate assembly is configured to close an opening of the housing. The cover plate assembly includes a support body, a groove is provided in the support body, and the area formed and enclosed by the inner ring of the groove is defined as S, where S satisfies: S=(K×C)/(T×V). K is a gas production coefficient of the electrode core, C is a capacity of the electrode core; T is pressure-relief time; and V is a pressure-relief speed.