Battery Current Collector Asymmetric Shielded Portion Design
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Solution Overview
Problem
Conventional battery designs face issues with mechanical connection strength, durability against thermal cycles, and susceptibility to peeling between current collectors and solid electrolyte layers, particularly due to exposed electrode extraction parts and differences in thermal expansion coefficients.
Innovation Solution
A battery configuration featuring cells electrically connected in parallel with a current collector structure that includes exposed and shielded portions, where the shielded portion is larger, and a solid electrolyte layer, along with a dummy current collector to reduce pressure variations and enhance adhesion, improves joining strength and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the current collector has a large exposed portion for electrode extraction, then ease of operation is improved, but mechanical strength and reliability deteriorate due to peeling and thermal stress
Solution Approach 1:
The current collector is designed with non-uniform exposed portions: a first exposed portion at the electrode extraction end and a second exposed portion at the opposite end, where the area of the second exposed portion is larger than the first. This local quality differentiation allows the smaller first exposed portion to suffice for electrode extraction while the larger second exposed portion provides enhanced mechanical support and thermal stress resistance, resolving the contradiction between ease of operation and reliability.
2Ease of operation
If the exposed portion area is increased for better electrode extraction, then ease of operation is improved, but the battery occupies more space increasing volume
Solution Approach 1:
The current collector features asymmetric exposed portions where the first exposed portion (for electrode extraction) is minimized in area, while the second exposed portion at the opposite end is enlarged. This allows the battery to maintain compact volume while ensuring adequate electrode extraction capability through the optimized first exposed portion, resolving the contradiction between ease of operation and volume minimization.
3Strength
If the current collector and solid electrolyte layer are firmly joined, then mechanical strength is improved, but peeling occurs during thermal cycles due to thermal expansion differences
Solution Approach 1:
The patent modifies the geometric parameters of the current collector by creating asymmetric exposed portions with different areas. The larger second exposed portion at the opposite end from the electrode extraction end acts as a stress compensation zone, absorbing thermal expansion differences between the current collector and solid electrolyte layer during thermal cycles, thereby preventing peeling while maintaining strong joining.
4Device complexity
If the current collector structure is simplified, then device complexity is reduced, but shock resistance deteriorates
Solution Approach 1:
The current collector employs an asymmetric structure with exposed portions of different areas at opposite ends, rather than a symmetric or uniform design. The larger second exposed portion provides enhanced mechanical support and shock absorption capability, improving shock resistance while maintaining relatively simple fabrication processes and structure.
Data Source
AI summary
A battery according to the present disclosure includes a plurality of cells that are electrically connected in parallel. Each of the plurality of cells includes a positive electrode layer, a negative electrode layer, a current collector that is in contact with the positive electrode layer or the negative electrode layer, and an electrolyte layer disposed between the positive electrode layer and the negative electrode layer. A side surface of the current collector includes an exposed portion exposed from the electrolyte layer and a shielded portion shielded by the electrolyte layer, and an area of the shielded portion is larger than an area of the exposed portion.