Stacked Button Cell Electrode Layout to Prevent Tab Short Circuits
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Solution Overview
Problem
Conventional button cells have reduced battery capacity and increased electrode assembly resistance due to the jelly-roll winding design, which also leads to damage and short circuits between electrode tabs of different polarities.
Innovation Solution
A button cell design featuring a stacked electrode assembly with first and second electrodes separated by insulating separators, where first and second electrode tabs are spaced apart along the circular border and connected at the center, preventing short circuits and optimizing the volume ratio for improved capacity and reduced resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the electrode assembly is wound in a jelly-roll shape, then the battery can be manufactured with conventional processes, but the volume ratio occupied by the electrode assembly is reduced, resulting in deteriorated battery capacity
Solution Approach 1:
The patent inverts the conventional jelly-roll winding approach by using a stacked configuration where electrodes and separators are layered alternately in a planar arrangement. This inversion allows the electrode assembly to occupy a larger volume ratio within the button cell, thereby improving battery capacity while remaining manufacturable through stacking processes.
Solution Approach 2:
The patent transitions from the conventional three-dimensional jelly-roll winding to a two-dimensional stacked arrangement. By changing the structural dimensionality, the electrode assembly achieves better space utilization and higher volume ratio, leading to improved battery capacity without compromising manufacturability.
2Device complexity
If the electrode assembly is wound in a jelly-roll shape, then the battery structure is simplified, but the resistance of the electrode assembly is increased and damage occurs to the electrode assembly
Solution Approach 1:
The patent inverts the conventional jelly-roll winding structure to a stacked configuration. This inversion eliminates the resistance and damage issues associated with winding while maintaining relatively simple structural complexity through the layered arrangement of electrodes and separators.
3Reliability
If electrode tabs are attached separately to the wound electrode assembly, then the electrical connection is established, but short circuits between electrode tabs with different polarities occur
Solution Approach 1:
The patent merges the electrode tabs of the same polarity together in the stacked configuration. By combining multiple electrode tabs into unified connection points, the design ensures proper electrical connection while preventing short circuits between tabs of different polarities, as the stacked structure naturally separates positive and negative terminals.
Data Source
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AI summary
A button cell includes a button-shaped electrode assembly including a plurality of first electrodes, a plurality of second electrodes, and a plurality of separators positioned between the plurality of first electrodes and the plurality of second electrodes, with the plurality of first electrodes, the plurality of second electrodes, and the plurality of separators being stacked in one direction. A first case and a second case are combined to house the electrode assembly; and a bonding portion insulating and bonds the first case and the second case. The electrode assembly further includes a plurality of first electrode tabs spaced apart from each other along a first part of a circular border of the electrode assembly, with each of the first electrode tabs extending from the plurality of first electrodes, each of the plurality of first electrode tabs extending to a center of a first surface of the electrode assembly, and the electrode tabs being connected to each other at the center of the first surface of the electrode assembly. A plurality of second electrode tabs are spaced apart from each other along a second part of the circular border of the electrode assembly from the plurality of second electrodes, extending to the center of the second surface of the electrode assembly, and connected to each other at the center of the second surface of the electrode assembly.