Prismatic Battery Cell Foil Thickness Layout for Lower Resistance
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Solution Overview
Problem
Prismatic battery cells experience heat generation and potential short circuits due to current bottlenecks, leading to decreased capacity and lifespan, as the uncoated portions of the electrode assembly increase resistance when current passes through.
Innovation Solution
The battery cell design incorporates a foil with varying thickness regions, including a protruding uncoated region with a greater thickness, which reduces resistance and heat generation by allowing current to flow more freely, and the active material is applied uniformly but with varying thicknesses to optimize contact areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the uncoated portion of the electrode assembly is made thinner to reduce resistance, then electrical conductivity improves, but mechanical strength and safety decrease
Solution Approach 1:
The foil is designed with varying thickness across different regions: a first region with uniform thickness, a second region with gradually increasing thickness, and a third protruding region with greatest thickness. This local quality variation allows the uncoated portion to provide both electrical conductivity (thinner regions) and mechanical strength (thicker regions), resolving the contradiction between conductivity and strength requirements.
2Temperature
If the uncoated portion protrudes more to reduce current bottleneck, then heat generation decreases, but structural complexity increases
Solution Approach 1:
The invention changes the thickness parameter of the foil continuously across different regions rather than using a uniform thickness. The second region has gradually increasing thickness and the third region has greatest thickness, creating a smooth parameter transition that reduces current bottleneck and heat generation while maintaining relatively simple manufacturing processes.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design effectively reduces resistance and heat generation, enhancing the battery cell's capacity and lifespan by minimizing current crowding and discontinuity, thereby improving safety and performance.
Implementation Method 1
when current passes through the protruding uncoated portion, resistance may increase and heat generation may occur due to a current bottleneck
Implementation Method 2
Heat may be generated in prismatic battery cells due to charging or discharging of battery cells
Data Source
AI summary
A battery cell including an electrode assembly including an active material and a foil and a can accommodating the electrode assembly is provided. The foil may include a first region covered with the active material and having a first thickness, a second region covered with the active material and extending from the first region, and a third region protruding from the second region, The third region may have a third thickness, greater than the first thickness, and the second region may have a second thickness, greater than the first thickness and less than the third thickness.