Secondary Battery Safety Valve Venting Through an Insulating Member
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing secondary batteries face issues where insulating members obstruct the flow of gas to the safety valve, preventing proper operation when gas pressure or temperature rises to a predetermined value, as seen in prior art configurations.
Innovation Solution
A sealed secondary battery design with a safety valve that includes a valve-part supporting portion with gas-passage forming portions on the case inner surface, allowing gas to flow through an insulating member and ensuring proper valve operation by forming passages between the insulating member and the valve-part supporting portion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an insulating member is interposed between the electrode body and the battery case to enhance electrical insulation, then electrical insulation between the electrode body and the battery case is improved, but the insulating member obstructs the flow of gas to the safety valve
Solution Approach 1:
The insulating member is divided into a body portion and a protruding portion that extends toward the safety valve. The protruding portion is specifically shaped to avoid blocking the gas passage, allowing gas to flow between the insulating member and the valve-part supporting portion while maintaining electrical insulation coverage.
Solution Approach 2:
A gas passage is formed between the insulating member and the valve-part supporting portion, acting as an intermediary channel that allows gas to bypass the insulating member and reach the safety valve. This intermediate space resolves the conflict between insulation coverage and gas flow requirements.
2Reliability
If the insulating member extends toward the lid member to provide comprehensive insulation coverage, then electrical insulation is enhanced, but the safety valve cannot operate properly when gas pressure rises
Solution Approach 1:
The insulating member has different structural characteristics in different regions: the body portion provides comprehensive insulation coverage, while the protruding portion is specifically designed with a shape that allows gas passage. This local differentiation enables the insulating member to simultaneously provide extensive coverage and maintain safety valve operability.
3Device complexity
If the safety valve is positioned to face the insulating member for compact design, then device complexity is reduced, but gas flow to the valve is blocked
Solution Approach 1:
The gas passage is formed in the radial dimension between the insulating member and the valve-part supporting portion, rather than requiring the valve to be positioned in a different axial location. This dimensional approach allows the valve to face the insulating member while gas flows through the radial gap, maintaining compact design without blockage.
Data Source
AI summary
A sealed secondary battery includes a battery case, an electrode body hermetically housed in the battery case, an insulating member interposed between the battery case and the electrode body, and a safety valve provided in the battery case at a position facing the insulating member to release gas out of the battery case when gas pressure or temperature in the battery case rises to a predetermined value or higher. The safety valve includes an openable valve part and a valve-part supporting portion annularly supporting the outer circumferential portion of the valve part and connected to the battery case. A case inner surface of the valve-part supporting portion, located inside relative to the valve part, is provided with a gas-passage forming portion that forms a gas passage communicating toward the valve part between the insulating member pushed toward the valve part by the gas and the valve-part supporting portion.