Secondary Battery Electrode Tab Stacking Ratio for Capacity
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Solution Overview
Problem
The existing secondary batteries face challenges in increasing capacity while maintaining sufficient output and reducing the size of the current collecting portion, particularly due to the limitations in the configuration of electrode tabs and their distribution within the wound electrode body.
Innovation Solution
The secondary battery employs a flat wound electrode body with a specific ratio of stacked electrode tabs to electrode layers, where the number of stacked layers of electrode tabs is set between 0.3 to 0.7, and the tabs are bent and connected to a current collecting member, optimizing the size and distribution to enhance capacity and reduce uneven current density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the number of stacked layers of electrode tabs is increased to maintain sufficient output, then the output of the secondary battery is improved, but the size of the current collecting portion increases, reducing the available space for the electrode body
Solution Approach 1:
The patent applies parameter changes by optimizing the ratio N1A/N1B (number of stacked layers of electrode tabs to number of stacked layers of electrode) to be 0.3 to 0.7, and setting the number of electrode tabs to 10 or more. This specific parameter configuration allows sufficient current collection while minimizing the space occupied by the current collecting portion, thereby increasing the electrode body size and battery capacity.
2Quantity of substance
If the size of the electrode body is increased to raise battery capacity, then the capacity of the secondary battery is improved, but the space available for the current collecting portion decreases
Solution Approach 1:
The patent resolves this contradiction by changing the parameters of electrode tab configuration: setting the number of electrode tabs to 10 or more and the ratio N1A/N1B to 0.3 to 0.7. This optimization reduces the space requirement for current collection, allowing the electrode body size to be increased and thus improving battery capacity.
3Device complexity
If electrode tabs are concentrated at one location to simplify connection, then the device complexity is reduced, but uneven current density distribution occurs, worsening reliability
Solution Approach 1:
The patent applies segmentation by distributing multiple electrode tabs (10 or more) across the electrode structure rather than concentrating them at a single location. This segmentation of current collection points ensures more uniform current density distribution throughout the electrode body, improving reliability while maintaining manageable connection complexity through systematic arrangement.
Data Source
AI summary
Provided is a technique increasing the capacity of secondary batteries. According to the technique disclosed herein, there is provided a secondary battery having a flat wound electrode body in which a first electrode and a second electrode different from the first electrode are laminated and wound with a separator interposed therebetween, and a first current collecting member. The wound electrode body has a plurality of first electrode tabs. Ten or more first electrode tabs are provided and stacked. In a thickness direction of the wound electrode body, a ratio (N1A/N1B) of the number N1A of stacked layers of the first electrode tabs and the number N1B of stacked layers of the first electrode satisfies 0.3 to 0.7. The plurality of first electrode tabs are bent and connected to the first electrode current collecting member.