Secondary Battery Sealing Plate Projections for Impact Resistance
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Solution Overview
Problem
Existing secondary batteries for electric vehicles and hybrid vehicles face reliability issues due to weak connections between the positive electrode collector and the sealing plate, which can be damaged by impact or vibration.
Innovation Solution
A secondary battery design featuring a metal sealing plate with projections and openings/cut-outs, where the first electrode collector is welded to the sealing plate at these projections, enhancing the connection's strength and reliability, and a battery pack configuration that connects adjacent batteries with a bus bar to distribute load effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the positive electrode collector is connected to the sealing plate using conventional methods, then the number of components can be reduced, but the connection strength is insufficient and can be damaged by impact or vibration
Solution Approach 1:
The sealing plate is divided into multiple projections (first projection, second projection, third projection) that are distributed at different positions. Each projection forms a separate welded connection point with the electrode collector, distributing the mechanical stress and preventing single-point failure under impact or vibration.
Solution Approach 2:
The connection structure transitions from a conventional planar connection to a three-dimensional structure with projections extending from the sealing plate surface. The projections create multiple elevated connection points that provide both mechanical strength and resistance to rotational forces applied to the electrode collector.
2Strength
If the electrode collector is connected with multiple projections, then the connection strength against rotational force is improved, but the manufacturing complexity increases
Solution Approach 1:
Multiple functions are merged into the sealing plate structure: it serves as both the sealing element and the connection structure for the electrode collector. The projections are formed directly on the sealing plate, eliminating the need for separate connection components and reducing assembly steps while providing enhanced mechanical strength.
3Reliability
If the first projection is made larger to increase welded connection area, then the reliability improves, but the space available for other components decreases
Solution Approach 1:
The sealing plate features localized projections at specific positions rather than a uniform structure. The first projection is enlarged at its distal end to create a recess that increases the welded connection area, while the rest of the sealing plate maintains its original configuration to preserve space for other components and electrode placement.
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 enhanced connection between the sealing plate and electrode collector improves the battery's reliability against impact and vibration, while the bus bar configuration ensures secure inter-battery connections, resulting in a more robust and reliable battery pack.
Implementation Method 1
the first projection and an edge portion of the first opening are welded and connected to each other
Data Source
AI summary
A secondary battery including an electrode body that includes a positive electrode plate and a negative electrode plate, an outer body that houses the electrode body, a metal sealing plate that seals an opening of the outer body, a positive electrode collector electrically connected to the positive electrode plate and the sealing plate, a negative electrode external terminal connected to the negative electrode plate through a negative electrode collector. In the secondary battery, a first projection and a second projection are formed on a surface of the sealing plate on a battery inner side, the positive electrode collector includes a first opening and a cut-out, the first projection is disposed in the first opening, the first projection and an edge portion of the first opening is welded and connected to each other, and the second projection is disposed in the cut-out.