Battery Pack Lid Deformation for Pressure Relief
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Solution Overview
Problem
Existing battery packs face pressure buildup issues due to gas discharge from battery cells, which can damage the frame, and existing solutions fail to effectively manage pressure while maintaining hermetic sealing.
Innovation Solution
A battery pack design featuring a case with a through hole and a lid that deforms to relieve pressure, using a seal and spacers to regulate compression and maintain hermetic sealing, preventing excessive pressure from damaging the frame.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the lid is tightly fixed to the through hole surrounding portion by a bolt to hermetically seal the case, then hermetic sealing is improved, but the compression ratio of the seal may be insufficient or excessive causing insufficient sealing or seal damage
Solution Approach 1:
A spacer is introduced as an intermediary component between the lid and the through hole surrounding portion. This spacer acts as a mediator that controls the compression force applied to the seal, preventing both insufficient compression (which would compromise sealing) and excessive compression (which would damage the seal). The spacer translates the bolt's tightening force into a controlled, regulated compression on the seal.
Solution Approach 2:
The spacer enables precise control of the seal compression parameter by physically limiting the distance the lid can move toward the through hole surrounding portion. This parameter control ensures the seal is compressed to the optimal degree for hermetic sealing without exceeding material limits, transforming an uncontrolled variable into a regulated one.
2Stress or pressure
If gas is discharged from the battery cell into the frame to relieve internal pressure, then pressure relief is improved, but the pressure in the frame increases which may damage the frame
Solution Approach 1:
The through hole in the frame allows gas to be extracted or removed from the sealed case interior and discharged to the external environment, bypassing the frame structure. This extraction path prevents gas accumulation that would otherwise build pressure within the frame, eliminating the harmful effect of frame damage while maintaining effective pressure relief.
3Reliability
If the seal is excessively compressed to ensure hermetic sealing, then hermetic sealing is improved, but the seal may be damaged
Solution Approach 1:
The spacer serves as a protective intermediary that stands between the lid (applying compressive force) and the seal. It regulates the interaction by limiting the maximum compression distance, ensuring the seal receives sufficient compression for hermetic sealing while preventing compression beyond the seal's structural limits, thus preserving seal integrity.
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
The solution effectively relieves internal pressure without compromising hermetic sealing, regulating seal compression to prevent damage and ensuring reliable operation.
Implementation Method 1
When internal pressure of the case rises, a portion of the lid is deformed in a direction in which the portion is separated from the through hole surrounding portion to relieve the internal pressure
Implementation Method 2
A seal is located between the lid and the through hole surrounding portion to hermetically seal the case. When the tightening force of the bolt compresses the seal, the above structure hermetically seals the case
Data Source
AI summary
This battery pack is provided with a housing, a case, a battery cell, a sealing material and a spacer. The case includes a lid member fixed to the housing so as to close a through-hole in the housing. The lid member is bolted to a through-hole peripheral part of the housing. When the internal pressure of the case rises, part of the lid member deforms in a direction away from the through-hole peripheral part, releasing the internal pressure of the case. The battery cell is accommodated inside of the case. The sealing material is arranged between the lid member and the through-hole peripheral part so as to ensure the air-tightness of the case. The spacer is arranged between the lid member and the through-hole peripheral part so as to maintain the interval between the lid member and the through-hole peripheral part.