Electrode Assembly Active Material Layer Distribution
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Solution Overview
Problem
Existing secondary battery electrode assemblies face challenges in optimizing the distribution and thickness of active material layers, which affects the energy density and space utilization efficiency, leading to suboptimal performance and capacity.
Innovation Solution
The electrode assembly features a configuration where the first and second electrode active material layers are strategically formed on specific surfaces and regions of the current collectors, with the second electrode active material layer initially coated on one surface before the first winding turn and expanded to both surfaces after the second winding turn, and the first electrode active material layer coated on both surfaces after the first winding turn, with the layers facing each other in the mandrel portion to enhance capacity and reduce thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the second electrode active material layer is coated on both surfaces from the beginning, then the capacity is increased, but the thickness and space utilization in the mandrel portion deteriorate
Solution Approach 1:
The electrode assembly is divided into different regions (mandrel portion and non-mandrel portion) with different active material layer configurations. The mandrel portion has reduced thickness by having the second electrode active material layer only on one surface, while other regions maintain both surfaces coated to ensure sufficient capacity.
Solution Approach 2:
Different regions of the electrode assembly have different quality characteristics. The mandrel portion uses a thinner configuration (second electrode active material layer on one surface only) to reduce thickness, while other portions use the full configuration (second electrode active material layer on both surfaces) to maintain capacity.
2Ease of manufacture
If the active material layers are uniformly distributed, then the manufacturing process is simplified, but the energy density and space utilization efficiency deteriorate
Solution Approach 1:
The active material layers are distributed non-uniformly according to the functional requirements of different regions. The mandrel portion has a specific configuration (second electrode active material layer on one surface only) to optimize space utilization, while other regions have different configurations to optimize capacity.
Solution Approach 2:
The electrode assembly is segmented into regions with different active material layer configurations. This segmentation allows each region to be optimized for its specific function (space utilization in mandrel portion, capacity in other portions) while maintaining a relatively simple manufacturing process.
3Volume of stationary object
If the electrode assembly thickness is reduced in the mandrel portion, then the space utilization efficiency is improved, but the capacity is reduced
Solution Approach 1:
The mandrel portion is given a different quality (reduced thickness with second electrode active material layer on one surface only) to improve space utilization efficiency, while other portions maintain the full quality (both surfaces coated) to ensure sufficient capacity.
Solution Approach 2:
The electrode assembly is divided into the mandrel portion and other portions, allowing the mandrel portion to be optimized for space utilization with reduced thickness, while other portions are optimized for capacity with full active material layer coverage.
Data Source
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AI summary
An electrode assembly (100) includes a first electrode plate (110) including a first electrode current collector (111) and a first electrode active material layer (112) thereon, a second electrode plate (120) including a second electrode current collector (121) and a second electrode active material layer (122) thereon, a separator (130) between the first electrode plate (110) and the second electrode plate (120), a first electrode tab (140) coupled to the first electrode current collector (111), and a second electrode tab (150) coupled to the second electrode current collector (121), wherein a region of the first electrode current collector (111) including the first electrode tab (140) faces a wound first electrode plate (110), wherein a region of the second electrode current collector (121) including the second electrode tab (150) faces a wound second electrode plate (120), and wherein the second electrode active material layer (122) is only on one surface of the second electrode current collector (121) in a region preceding a first winding turn of the second electrode plate (120).