Deformed Electrochemical Cell Can for Uniform Stack Pressure
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Solution Overview
Problem
Some electrochemical cells within batteries exhibit a significantly shorter lifespan compared to others, leading to anomalies and complications in battery performance.
Innovation Solution
The electrochemical cell design includes a can with locally deformed portions on its faces, creating a more uniform pressure profile on the stack, which enhances the cell's lifespan and prevents anomalies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the can faces are left flat and undeformed, then the manufacturing process is simple, but the pressure profile on the stack becomes non-uniform leading to cell anomalies and reduced lifespan
Solution Approach 1:
The patent applies local deformation to specific regions of the can faces (the portions facing the stack) while leaving other regions relatively flat. This localized modification creates the necessary pressure uniformity without requiring complete redesign of the entire can structure, thus improving reliability while limiting complexity increase
Solution Approach 2:
The can faces are pre-deformed during manufacturing before the cell is assembled and sealed. This preliminary action ensures that when the cell is filled and sealed, the deformation is already in place to provide uniform pressure distribution, preventing anomalies before they can occur during cell operation
2Reliability
If the can faces are deformed to create uniform pressure, then the pressure profile becomes uniform improving cell lifespan, but the manufacturing process becomes more complex
Solution Approach 1:
The patent modifies the geometric parameters of the can faces by introducing controlled deformations with specific characteristics (depth between 3% and 6% of the stack width, convexity turned towards the interior volume). These parameter changes are optimized to achieve the desired pressure uniformity while being compatible with existing manufacturing capabilities
Solution Approach 2:
The deformation of the can faces introduces curvature to otherwise flat surfaces. This curvature is designed to redirect and distribute the sealing pressure more uniformly across the stack, transforming the pressure distribution pattern without requiring complex manufacturing equipment
3Reliability
If no deformation is applied to the can faces, then the manufacturing process is straightforward, but some cells exhibit significantly lower lifespan compared to others
Solution Approach 1:
The deformation is applied locally to the portions of the can faces that directly contact or face the stack, while the rest of the can structure remains relatively simple. This localized approach ensures lifespan consistency without requiring complex modifications throughout the entire can design
Solution Approach 2:
The can face deformation creates an asymmetric geometry where the portions facing the stack have a different profile (convex deformation) compared to the outer portions of the can. This asymmetric design is specifically tailored to correct the pressure distribution issue that causes lifespan variability among cells
Data Source
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AI summary
An electrochemical cell (12) comprising: - a can (14) comprising at least two can faces (24), - a cover (16) fixed to the can (14), the can (14) and the cover (16) defining an interior volume (18), - a stack (22) extending between the two can faces (24) in a first transverse direction (T1), the interior volume (18) comprising a region (26) extending between the stack (22) and the cover (16) in a second transverse direction (T2). Each of the two can faces (24) comprises a first portion (32) facing the stack (22) and defining a plane (P1, P2), and a second portion (34) facing the region (26.) and presenting a local deformation (40) in the first transverse direction (T1) towards the interior volume (18) with respect to the planes (P1, P2).