Electrode Assembly Ceramic Layer Winding End Short-Circuit Prevention
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Solution Overview
Problem
Existing lithium-ion battery separators are prone to internal short-circuits due to heat generation, which can lead to fires or explosions, and current ceramic separators increase material costs and battery volume while reducing mass-to-battery capacity.
Innovation Solution
Incorporating a ceramic layer along a specific length of the electrode assembly, extending from the winding end to the outer ring, to prevent short-circuits and enhance safety, while maintaining or improving mass-to-battery capacity and reducing manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a ceramic separator is used to prevent internal short-circuits, then safety is improved, but material cost and battery volume increase while mass-to-battery capacity decreases
Solution Approach 1:
The patent applies local quality by positioning the ceramic layer specifically at the winding end outer ring of the electrode assembly rather than using a ceramic separator throughout. This localized application provides safety enhancement precisely where short-circuit risks are highest (at the winding end) while minimizing the quantity of ceramic material used, thereby maintaining mass-to-battery capacity.
Solution Approach 2:
The patent segments the protective function by separating the ceramic layer from the bulk separator material. Instead of using a complete ceramic separator, only a portion (the winding end outer ring area) is treated with ceramic coating, while the rest of the separator maintains its original composition. This segmentation reduces overall material usage and cost while providing targeted safety protection.
2Reliability
If a ceramic layer is added to prevent short-circuits, then reliability is improved, but device complexity increases
Solution Approach 1:
The patent merges the ceramic protective layer with the existing separator structure at the winding end area. Rather than adding a separate ceramic separator component, the ceramic material is applied as a coating or integrated layer on the separator at the critical winding end region, combining the protective function with the existing separator to avoid increasing structural complexity.
3Reliability
If a ceramic separator is used throughout, then safety against high-temperature short-circuits is improved, but manufacturing cost increases
Solution Approach 1:
The patent applies local quality by restricting ceramic material application to the winding end outer ring area where short-circuit risks are concentrated during manufacturing and operation. This localized approach reduces the total quantity of expensive ceramic material required compared to using a full ceramic separator, thereby lowering manufacturing cost while maintaining safety effectiveness at the critical location.
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 ceramic layer effectively prevents internal short-circuits during high-temperature events, such as the nail test, without causing explosions, and reduces the risk of overheating, while allowing for a more cost-effective and efficient secondary battery design.
Implementation Method 1
the sheet-type separator to contract. When the sheet-type separator contracts, due to the generated heat, the positive electrode plate contacts the negative electrode plate, where the contraction occurs
Implementation Method 2
the separator absorbs an electrolyte needed for a battery reaction, and has high ion conductivity
Data Source
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AI summary
An electrode assembly comprises: a positive electrode plate including a positive electrode active material applied to a positive electrode collector, a negative electrode plate including a negative electrode active material applied to a negative electrode collector, a separator disposed between the positive electrode plate and the negative electrode plate, and a ceramic layer disposed on a portion of the positive or negative electrode plate, adjacent to an outer surface of the electrode assembly. The positive electrode plate, the negative electrode plate, ceramic layer, and the separator are wound together. The ceramic layer prevents a short-circuit between the positive electrode plate and the negative electrode plate, and extends along between about 40% and 90% of the length of the positive or negative electrode plate, from a winding end thereof. There is also disclosed a secondary battery including the electrode assembly.