Single Pouch Battery Cell Architecture to Limit Defect Propagation
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Solution Overview
Problem
Conventional battery manufacturing faces issues such as defect propagation, fire hazards due to flammable electrolytes, and metal contamination during welding, which affect the safety and performance of lithium-ion battery cells.
Innovation Solution
The use of single pouch battery cells, where each cell is encapsulated in a pouch with an anode, cathode, and separator, reduces defect propagation and fire hazards by isolating electrochemical reactions and preventing metal contamination, while allowing for thinner current collectors for improved energy density and handling.
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 hazards increases
Solution Approach 1:
The invention divides the battery system into multiple independent pouch cells, each containing a limited number of stacks (e.g., 1-3 stacks per pouch). These pouches are then connected in parallel to achieve the desired total capacity. This segmentation isolates electrochemical reactions and prevents defect propagation between stacks, while maintaining high capacity through parallel connection of multiple smaller units.
2Reliability
If conventional welding is used to join battery tabs and bus-bars to form modules, then electrical connectivity is achieved, but metal contamination occurs
Solution Approach 1:
The invention replaces the welding process (thermal/mechanical system) with mechanical compression and conductive adhesive bonding. Pouches are compressed between conductive bus-bars using compression plates and fasteners, creating electrical connectivity without metal particulate contamination. This substitution eliminates the harmful effects of welding while maintaining reliable electrical connections.
3Strength
If thick current collectors are used in conventional battery cells, then structural strength is maintained, but energy density decreases
Solution Approach 1:
By dividing the battery into multiple smaller pouches, each containing fewer stacks, the mechanical load on each current collector is reduced. This allows the use of thinner current collectors in each pouch while maintaining sufficient structural strength. The overall battery maintains adequate strength through the distributed architecture of multiple pouches connected in parallel.
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.