Battery Tab Terminal Structure for Stress-Relieved Module Stacking
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Solution Overview
Problem
When multiple batteries are stacked, stress is generated at the joint portion of the current collector terminal and current collector tabs, which can deteriorate bondability and cause damage.
Innovation Solution
A battery design featuring current collector tabs with a laminated connection portion and a thick current collector terminal with protruding portions, where the tabs are housed in a laminate film, reducing stress at the joint by dispersing it through a curved structure and strategic overlap of protruding portions in a battery module.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple batteries are stacked and adjacent current collector terminals are joined together, then battery module assembly is achieved, but stress is generated at the joint portion of the current collector terminal and current collector tabs which deteriorates bondability and may cause damage
Solution Approach 1:
The current collector terminal is divided into a base portion and a protruding portion. The protruding portion extends from the base portion to an opposite side from the electrode body, allowing the terminal to be joined at the base portion while the protruding portion provides stress relief space, preventing stress concentration at the joint between the terminal and tabs.
Solution Approach 2:
The intermediate portion of the current collector tabs includes a curved structure where the tab is curved such that parts of the intermediate portion face each other. This curved structure disperses stress generated during battery stacking, preventing stress concentration at the joint portion between the current collector terminal and tabs.
2Ease of manufacture
If current collector tabs are directly connected to current collector terminal without curved structure, then manufacturing is simpler, but stress concentration occurs at the joint portion causing damage
Solution Approach 1:
The intermediate portion of the current collector tabs includes a curved structure where the tab is curved such that parts of the intermediate portion face each other. This curved structure disperses stress generated during battery stacking, preventing stress concentration at the joint portion between the current collector terminal and tabs.
Solution Approach 2:
The current collector tabs include a laminated connection portion where the connection portions of multiple tabs are laminated in the thickness direction. The main surface of the laminated connection portion is joined to the inner surface of the current collector terminal, distributing the connection across multiple layers and reducing stress concentration.
Data Source
AI summary
In a battery, each current collector tab includes a root portion, a connection portion, and an intermediate portion. Current collector tabs include a laminated connection portion in which the connection portions are laminated. A current collector terminal includes an inner surface facing a side surface portion of an electrode body, and a side surface disposed along an outer edge of the inner surface. A laminate film is disposed on the side surface. A main surface of the laminated connection portion is joined to the inner surface. In a plan view in an electrode body laminating direction, the current collector terminal includes a base portion including a first end portion corresponding to the position of the inner surface and a second end portion opposite to the first end portion, and a protruding portion protruding from the base portion to an opposite side of the base portion from the electrode body.