Honeycomb Negative Electrode Layout for Battery Cycle Endurance
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Solution Overview
Problem
Existing three-dimensional electrode structures for batteries face challenges in enhancing cycle endurance, particularly due to internal stress and potential short circuits caused by volume changes during charge and discharge cycles.
Innovation Solution
The battery design incorporates a honeycomb core negative electrode with a higher filling factor of the separator in the inner circumferential part compared to the central part, which acts as a stress-relieving component, reducing the likelihood of short circuits and improving cycle endurance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a three-dimensional electrode structure with honeycomb core is used, then energy density is enhanced, but cycle endurance deteriorates due to internal stress and potential short circuits
Solution Approach 1:
The separator is designed with non-uniform thickness, featuring a first thickness in the central part of the hollow cells and a second thickness in the inner circumferential part. This local quality variation allows the separator to provide enhanced stress relief at the circumferential wall region while maintaining adequate separation throughout, directly resolving the contradiction between energy density and cycle endurance by addressing the specific stress concentration problem without compromising overall battery performance
2Reliability
If the separator thickness is increased to prevent short circuits, then reliability improves, but energy density deteriorates due to reduced active material space
Solution Approach 1:
The separator thickness is optimized locally rather than uniformly increased. The first thickness in the central part and the second thickness in the inner circumferential part are specifically designed to provide adequate separation and stress relief only where needed near the circumferential wall, preventing short circuits while minimizing the overall volume occupied by the separator, thus preserving energy density
3Stability of the object's composition
If the honeycomb core structure is made more rigid to maintain shape, then structural stability improves, but internal stress increases causing separator damage
Solution Approach 1:
The separator's non-uniform thickness design allows it to locally accommodate the expansion and contraction of the honeycomb core at the circumferential wall region. The increased second thickness in the inner circumferential part provides a buffer zone that can absorb dimensional changes, reducing internal stress transmission to the separator while the overall honeycomb structure maintains its structural stability through the partition framework
Data Source
AI summary
The negative electrode forms a honeycomb core. The honeycomb core includes a first face, a second face, a partition, and a circumferential wall. The second face faces the first face. The partition is formed between the first face and the second face. In a cross section parallel to the first face, the partition separates a plurality of hollow cells. The separator includes a first layer. The first layer covers at least part of the partition. The cross section parallel to the first face includes a central part and an inner circumferential part. The central part is surrounded by the inner circumferential part. In the central part, the hollow cells have a first average filling factor. In the inner circumferential part, the hollow cells have a second average filling factor. The second average filling factor is 2.1 times or more the first average filling factor.