Wound Battery Cell Tail Structure for Short-Circuit Prevention
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Solution Overview
Problem
The uncovered aluminum foil at the tail of the battery cell occupies volume, reducing energy density and increases the risk of short circuits, leading to thermal runaway and fire.
Innovation Solution
A battery cell structure with an outermost electrode plate having a current collector with an active layer on one side, using insulating adhesive on the uncovered foil region and a thermal expansion material in the coating to prevent short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If uncovered aluminum foil is left at the tail of the battery cell, then the structure is simple and manufacturing is easy, but the energy density is reduced due to occupied volume and short circuit risk increases
Solution Approach 1:
The patent removes the uncovered aluminum foil from the tail end of the battery cell, extracting the problematic element that causes short circuits. Instead of leaving the foil exposed, the invention applies insulating adhesive to cover only the necessary portions, eliminating the safety hazard while maintaining structural integrity.
Solution Approach 2:
The patent applies insulating adhesive locally only where needed - specifically on the covered aluminum foil regions at the tail end - rather than covering the entire foil or using uniform protection throughout. This localized approach prevents short circuits at critical areas while minimizing material usage and maintaining energy density.
2Reliability
If green adhesive is attached to the uncovered aluminum foil and edge of coating, then short circuit risk is reduced, but the energy density is reduced due to occupied volume
Solution Approach 1:
The patent applies insulating adhesive only to specific local areas - the covered aluminum foil regions at the tail end - rather than applying adhesive uniformly across all surfaces. This localized application provides short circuit prevention exactly where needed while minimizing the volume occupied by adhesive material, thereby preserving energy density.
Solution Approach 2:
The patent extracts and removes the uncovered aluminum foil that would require adhesive coverage, eliminating the need for extensive adhesive application. By removing the exposed foil entirely and applying adhesive only to necessary covered regions, the invention reduces both short circuit risk and adhesive material volume.
3Loss of substance
If uncovered aluminum foil is present at the battery cell tail, then material consumption is reduced, but thermal runaway risk increases due to short circuit susceptibility
Solution Approach 1:
The patent removes the uncovered aluminum foil from the battery cell tail, extracting the element that creates thermal runaway risk through short circuits. By eliminating the exposed foil that could contact the anode, the invention prevents the chain reaction that leads to thermal runaway while minimizing material usage.
Solution Approach 2:
The patent applies insulating adhesive in advance to covered aluminum foil regions before any short circuit could occur. This preliminary protective action prevents the potential contact between cathode foil and anode that would initiate thermal runaway, addressing the harmful factor before it can manifest.
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
Improves energy density and safety by preventing short circuits and reducing material consumption while minimizing thermal runaway risks.
Implementation Method 1
the first coating comprises a thermal expansion material
Data Source
AI summary
A battery cell includes a first electrode plate, a second electrode plate, and an insulating adhesive. The first electrode plate includes a first current collector, a first coating, and a first active layer, the first coating is disposed between the first current collector and the first active layer and includes a thermal expansion material. The first electrode plate and the second electrode plate are wound at intervals, the first electrode plate is the outermost electrode plate of the battery cell and further includes a first end which is a winding ending end, a surface of the first current collector at the first end facing toward the center of the battery cell is provided with the first active layer. The insulating adhesive includes a first sub-insulating adhesive disposed on a surface of the first current collector on the outermost side of the battery cell facing away from the first active layer.