Single Pouch Battery Cell Layout to Limit Defect Propagation
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Solution Overview
Problem
Conventional battery manufacturing faces issues such as defect propagation, fire hazard due to flammable electrolyte, and metal contamination during welding, leading to reduced manufacturing yield and safety risks.
Innovation Solution
The use of single pouch battery cells, where anode, cathode, and separator are contained within a pouch, mitigates defect propagation and reduces fire hazard by isolating electrodes from welding sparks and metal contamination, while employing thinner current collectors for improved handling and electrical conduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If multiple stacks are connected in parallel within a single pouch to increase capacity, then the battery capacity increases, but the risk of defect propagation and fire hazard increases
Solution Approach 1:
The patent divides the battery system into multiple independent pouch cells, each containing a single stack rather than multiple stacks in one pouch. This segmentation isolates potential defects to individual cells, preventing propagation across the entire battery while still achieving high capacity through parallel connection of multiple independent cells. Each pouch acts as an independent containment unit with its own electrolyte volume, physically separating failure modes.
2Power
If multiple battery cells are joined together through welding of tabs and bus-bars to form modules, then the power and capacity needs are met, but metal contamination and fire hazard from welding sparks increase
Solution Approach 1:
The patent replaces the welding process with a mechanical compression system. Conductive plates are pressed against the tabs of multiple pouch cells using compression force, creating electrical connections without any welding sparks or metal contamination. This mechanical substitution eliminates the harmful effects of welding while maintaining the necessary electrical connectivity for high power output.
3Strength
If thick current collectors are used in conventional battery cells, then structural strength is maintained, but handling difficulty and electrical resistance increase
Solution Approach 1:
The patent changes the thickness parameter of the current collector to an optimized range (5-20 micrometers) that balances mechanical strength and electrical conductivity. By using thinner current collectors within this optimized range, the patent improves handling ease and reduces electrical resistance while maintaining sufficient structural strength through the overall cell design and compression forces applied during operation.
4Quantity of substance
If a large number of stacks are placed in one pouch, then the battery capacity increases, but the amount of electrolyte required increases proportionally, increasing fire hazard
Solution Approach 1:
The patent segments the electrolyte into multiple isolated portions, each contained within its own pouch cell. Instead of one large pouch containing all stacks and electrolyte, multiple smaller pouches each contain a single stack and a proportional amount of electrolyte. This segmentation reduces the fire hazard in each individual cell while achieving the same total capacity through parallel connection of multiple cells.
Data Source
AI summary
Apparatus, systems, and methods described herein relate to the manufacture and use of single pouch battery cells. In some embodiments, an electrochemical cell includes a first current collector coupled to a first portion of a pouch, the first current collector having a first electrode material disposed thereon, a second current collector coupled to a second portion of the pouch, the second current collector having a second electrode material disposed thereon, and a separator disposed between the first electrode material and the second electrode material. The first portion of the pouch is coupled to the second portion of the pouch to enclose the electrochemical cell.