Flat Battery Cells With Structural Frame
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Pouch-type lithium-ion and lithium-polymer battery cells face issues with swelling, which can crack the foil envelope and lead to leakage, and are limited in thickness, restricting battery capacity and safe gas management during pressure changes.
Innovation Solution
A frame with a predetermined breaking point and lashing lugs is introduced, allowing for increased thickness, safe electrolyte injection, and controlled gas release, while maintaining hydrogen-tightness and structural resilience.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the pouch volume is enlarged to increase battery capacity, then the battery capacity increases, but the thickness limitation of aluminum foils (about 8 mm) disrupts the pouch structure
Solution Approach 1:
The pouch is divided into multiple layers (first pouch layer and second pouch layer) that can be stacked together. This segmentation allows the battery to achieve greater thickness and capacity without relying on a single thick aluminum foil, thereby avoiding structural disruption while enabling increased battery capacity through stacked configurations
Solution Approach 2:
The invention transitions from a single-layer pouch structure to a multi-layer stacked structure, adding the vertical stacking dimension. This allows the battery to increase capacity not just by expanding in-plane dimensions but by stacking multiple thinner pouch layers vertically, overcoming the 8 mm thickness limitation of individual aluminum foils
2Reliability
If manufacturers add excess film to create a gas bag to prevent swelling, then swelling prevention improves, but it becomes difficult to guide gases to safe locations and potential leakages occur
Solution Approach 1:
The pouch structure incorporates specific local features including rupture discs positioned at predetermined locations and designated gas venting channels. Instead of uniformly adding excess film throughout, the solution applies localized structural modifications that enable controlled gas management at specific points, maintaining swelling prevention while providing defined pathways for gas release
Solution Approach 2:
The invention introduces intermediary structures such as rupture discs and gas venting channels that act as mediators between the internal cell pressure and the external environment. These intermediaries provide controlled interfaces for gas release, preventing uncontrolled cracking and leakage while managing the harmful gas by directing it through designated pathways
3Manufacturing precision
If an injection lance is used for filling the cell with electrolyte, then the correct amount of electrolyte can be metered, but disruptions in the pouch structure occur creating potential leakages
Solution Approach 1:
The pouch structure is prepared in advance with pre-formed injection channels and reinforced areas at the injection sites. These preliminary structural features are built into the pouch during manufacturing, allowing the injection lance to access pre-designated pathways that minimize structural disruption and prevent leakage while enabling precise electrolyte metering
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
The present invention relates to lithium ion or lithium-polymer battery cells, and to lithium ion or lithium-polymer battery packs for use in automotives or portable power tools, garden tools and home appliances. The battery cell or battery cell precursor comprises a frame of a hydrogen-tight material such as aluminum, an aluminum composite or steel, the frame exhibiting an upper side and a lower side; two or more sheets made of a hydrogen-tight material, such as aluminum, an aluminum-polymer-composite or steel, wherein one or more of the two or more sheets being affixed onto the upper side of the frame and one or more other of the two or more sheets being affixed onto the lower side of the frame; wherein the frame together with the two or more sheets being affixed to the frame to form an inner hollow space comprising an electrode assembly of one or more anodes, one or more cathodes and one or more separators interposed between anode and cathodes; and wherein one or more positive and one or more negative electrode terminals protrude from the inner hollow space to an outside of the battery cell. The presence of a frame hitherto for unknown allows the production of battery cells having an increased thickness, and connected therewith higher capacity versus the common pouch cells wherein pouch ends are directly connected to each other. Further, the frame allows for the presence of various functions at a defined location.