Pouch Battery Cell Cover Separator to Prevent Gas-Driven Electrode Separation
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Solution Overview
Problem
Existing battery cell structures face issues with position-specific height deviations and separation of electrode components due to gas penetration and electrolyte depletion, leading to potential separation of electrode plates and separators.
Innovation Solution
A battery cell design featuring a cover separator that wraps the electrode assembly, comprising a pair of cover separators tightly contacting the electrode assembly's surfaces, including through-holes for electrode tabs, and connected via an adhesive or lamination, ensuring uniform coverage and preventing gas penetration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If tapes are used to fix the electrode assembly, then the electrode assembly can be fixed in position, but position-specific height deviations occur and gas penetration causes separation of electrode components
Solution Approach 1:
The harmful tapes are completely removed from the electrode assembly structure. Instead of using tapes for fixation, the invention extracts this function by using the cover separator that wraps around the electrode assembly, eliminating the source of chemical reactions with electrolyte and subsequent reliability issues
Solution Approach 2:
A cover separator made of flexible thin film material (such as polyolefin) is introduced to wrap around the electrode assembly. This flexible shell provides both mechanical fixation to prevent height deviations and chemical resistance to prevent separation, replacing the harmful tape structure
2Stability of the object's composition
If tapes are attached to wrap around the electrode assembly, then fixation is achieved, but adhesive layer reacts with electrolyte causing browning and depletion
Solution Approach 1:
The adhesive layer that causes chemical reactions with electrolyte is completely extracted and removed from the structure. The fixation function is transferred to the cover separator which provides mechanical wrapping without chemical interaction
Solution Approach 2:
The invention replaces the long-lived but chemically reactive tape with a disposable-style cover separator that is chemically inert. The cover separator is designed to be replaced or is inherently resistant, preventing cumulative damage from chemical reactions
3Stress or pressure
If gas is captured in the terrace portion and reaches critical point, then pressure builds up, but gas penetrates into the cell assembly causing separation
Solution Approach 1:
The cover separator acts as a flexible protective shell that conforms to the electrode assembly shape and provides continuous coverage. This flexible barrier prevents gas penetration while accommodating pressure changes, maintaining reliability under stress conditions
Solution Approach 2:
The cover separator provides beforehand protection by creating a barrier against gas penetration before gas can cause separation. It cushions the electrode assembly against the harmful effects of gas pressure buildup in advance
Data Source
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AI summary
Disclosed are a battery cell with an improved structure and a battery module including the same, and more particularly a battery cell including an electrode assembly having an electrode tab protruding therefrom, the electrode assembly including a positive electrode, a separator, and a negative electrode, a pair of cover separators located so as to wrap the electrode assembly, the pair of cover separators including a first cover separator and a second cover separator, a pouch case configured to receive the electrode assembly and the pair of cover separators, an electrode lead having one side connected to the electrode tab and an other side protruding outward from the pouch case, and an insulating film located between the pouch case and the electrode lead and a battery module including the same.