US20240429495A1 claims a structure that arranges the stacked layers inside a prismatic battery can in an inverted-U shape.
Patent Bibliographic Information
US20240429495A1 (“Prismatic Inverted-U Battery Stack Geometry”), Applicant: General Motors, Original Filing Date: 2023-06-23, Publication Date: 2024-12-26 (Publication No. 20240429495, confirmed via USPTO/Justia Patents, Google Patents). It claims a structure in which the stacked layers inside a prismatic battery can are folded and arranged in an inverted-U shape.
Per the Google Patents published document, Claim 1 specifies an orthotropic structure where the stacked layers’ in-plane thermal conductivity exceeds the transverse thermal conductivity, and dependent claims 2–7 limit this conductivity ratio to greater than 10.0, the upper-region height to 10–20% of the total, and the stack aspect ratio to 1.5–3.0 (source: Google Patents published application). The specification states that the inverted-U structure achieves a thermal-response delay exceeding 1,350 seconds and a peak temperature below 155°C even under a thermal-runaway event in an adjacent can (same source). The stacked-layer materials are specified as a copper current collector, graphite/silicon/tin-based anode, polyethylene/polypropylene microporous separator, lithium-cobalt/manganese/iron-phosphate cathode, and aluminum current collector (same source).
Patent Claim Elements vs. Target Equipment Comparison (Claim Chart)
| Claim Element | Patent Disclosure | Corresponding Structure in Typical Prismatic Cell Stacking/Winding Equipment | Correspondence |
|---|---|---|---|
| Multilayer stacked layers inside prismatic can | Continuous sheet arranged folded into inverted-U shape | Zigzag stacking or winding-then-pressing method used in parallel | Partial correspondence (differing stack geometry) |
| Upper horizontal heat-transfer path | Enhanced horizontal-direction heat dissipation at can top | Top is typically used as space for electrode tab extraction | Different structure (design-around potential) |
| Lower vertical heat-transfer path | Enhanced vertical-direction heat dissipation near can bottom | Bottom cold-plate contact method is common | Partial correspondence |
| Folding process | Folding process shaping the sheet into an inverted-U | Similar function to the folding unit in zigzag stacking equipment | Partial correspondence (forming trajectory may differ) |
Practical Significance
The inverted-U stacking geometry is an idea for separating the heat-dissipation paths at the top and bottom of the can, and it is difficult to directly use the folding-unit trajectory of existing zigzag stacking equipment as-is. Redesigning the folding head’s reciprocating trajectory to match inverted-U forming leaves room to design around part of this claim element (this is not a conclusion on infringement, and claim scope interpretation requires separate review), but the design concept itself of separating the upper and lower heat-transfer paths is worth referencing when re-reviewing pack cold-plate placement. To give the can top a heat-dissipation function, interference with the electrode-tab extraction structure that occupies the top space must also be reviewed.
The numeric limitations of a conductivity ratio exceeding 10x and an upper-region height of 10–20% imply that actual stacking equipment would need to manage compression pressure or stack pitch differently between the upper and lower regions. Conventional zigzag stacking equipment often applies uniform compression pressure across the entire stack, so implementing this patent’s claims as-is could require an additional zone-variable compression-pressure control capability (estimated; whether commercial equipment currently offers variable compression is undisclosed).
Shop-notes: Options for implementing zone-based thermal-conductivity anisotropy include a lower-cost approach that only partially varies the stacked layer’s orientation (grain direction), versus a higher-cost approach that applies different materials to the upper and lower regions (e.g., a high-thermal-conductivity composite foil on top, standard aluminum foil on the bottom). The former has a cost advantage with no material change but requires demanding orientation-precision control, while the latter adds material cost but makes it easier to reliably reproduce the 10x conductivity-ratio requirement — separate from any design-around strategy, the latter may be preferable for building a genuinely reliable thermal-management structure (estimated).
One-Line Summary: The inverted-U stack’s core is separating the can’s upper/lower heat-dissipation paths, and redesigning the folding trajectory leaves room to design around part of the claim (final judgment on patent validity requires separate review).
Design Reflection Checklist
- Confirm whether zone-based (upper/lower) variable compression-pressure control is available on the stacking line
- Review own designs against the numeric limitations of claims 2–7 (conductivity ratio >10x, aspect ratio 1.5–3.0) for design-around purposes (final infringement determination requires separate legal review)
- Pre-review interference between an upper thermal-dissipation structure and the electrode-tab extraction space