Rechargeable Battery Electrode Terminal Fixing Mechanism
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Solution Overview
Problem
Rechargeable batteries face increased contact resistance due to loosening of the nut connecting the electrode terminal, which is exacerbated by vibration, temperature changes, and impacts, limiting the fastening force and stability of the electrical connection.
Innovation Solution
A rechargeable battery design featuring an auxiliary connection member with a flange portion and connection shaft, where the connection shaft penetrates the bus bar and is secured with a pressing member, and a fixing member inside the case to stabilize the electrode terminal, enhancing mechanical strength and reducing contact resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a nut is used to fasten the connection plate to the electrode terminal, then the electrical connection is established, but the contact resistance increases due to nut loosening under vibration and temperature changes
Solution Approach 1:
The connection structure is divided into multiple components: electrode terminal, connection plate, nut, and washer. This segmentation allows each component to perform its specific function - the washer distributes load, the nut provides adjustable fastening, and the connection plate ensures electrical contact, collectively solving the reliability-strength contradiction
Solution Approach 2:
The washer is pre-installed between the nut and connection plate before fastening. This preliminary action creates a load-distributing interface that maintains consistent contact pressure, preventing nut loosening under vibration and temperature changes while maintaining low contact resistance
2Reliability
If the nut is tightened strongly to reduce contact resistance, then the electrical connection improves, but the device complexity and assembly difficulty increase
Solution Approach 1:
The washer is designed to automatically distribute the fastening force from the nut across the connection plate surface. This self-service mechanism eliminates the need for complex adjustment procedures, maintaining low contact resistance through passive load distribution rather than active control, thus reducing assembly complexity
3Reliability
If copper or aluminum is used for the electrode terminal to ensure good electrical conductivity, then the electrical performance improves, but the mechanical strength decreases making the nut prone to loosening
Solution Approach 1:
The washer acts as an intermediary between the nut and the soft copper/aluminum connection plate. It transfers and distributes the fastening force from the nut, preventing direct stress concentration on the electrically conductive but mechanically weak terminal material, thus maintaining both electrical conductivity and mechanical stability
Solution Approach 2:
The connection structure uses a composite approach combining different materials: copper or aluminum for electrical conductivity in the terminal, and a harder material for the washer to provide mechanical support. This material combination allows each component to optimize for its primary function while working together to solve the conductivity-strength contradiction
Data Source
AI summary
A rechargeable battery includes an electrode group for producing electricity, a case for housing the electrode group, a cap plate combined with the case, an electrode terminal electrically coupled to the electrode group, and a fixing member disposed inside the case and combined to the support shaft portion. The electrode terminal includes a head portion disposed outside the case, and a support shaft portion protruding from the head portion and penetrating the cap plate. Contact resistance of the rechargeable battery can be reduced with this configuration. A battery module includes a plurality of rechargeable batteries and bus bars electrically connecting at least two of the rechargeable batteries, wherein each rechargeable battery includes a case with an internal space, a cap plate combined with the case, an electrode terminal including a head portion caught on the cap plate and a support shaft portion protruding from the head portion and penetrating the cap plate, and a fixing member disposed inside the case and combined to the support shaft portion.