Power Storage Module Sealing Body with Differential Resin Shrinkage
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Solution Overview
Problem
The existing power storage modules experience electrolytic solution leakage due to the alkali creep phenomenon, where the solution seeps through the sealing body and electrode plate, leading to potential corrosion and short-circuiting issues.
Innovation Solution
A power storage module design featuring a sealing body with a first resin portion welded to the edge of the bipolar electrode and a second resin portion surrounding it, where the first resin portion has a lower mold shrinkage factor, melt viscosity, and melting point than the second resin portion, reducing the likelihood of gap formation and subsequent leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sealing body is provided to seal the electrode plate, then electrolytic solution leakage is prevented, but gap formation due to mold shrinkage creates leakage passages
Solution Approach 1:
The sealing body is designed with different resin portions having different mold shrinkage factors at different locations. The first resin portion in contact with the electrode plate has a lower mold shrinkage factor to minimize gap formation, while the second resin portion has a higher mold shrinkage factor to ensure proper sealing. This local differentiation of material properties resolves the contradiction between preventing leakage and avoiding gap formation.
Solution Approach 2:
The sealing body is constructed as a composite structure comprising multiple resin portions with different shrinkage characteristics. By combining materials with different mold shrinkage factors in a single sealing body, the invention achieves both tight sealing contact with the electrode plate and effective leakage prevention, resolving the contradiction between sealing performance and gap formation.
2Manufacturing precision
If the first resin portion has high fluidity (low melt viscosity), then it fills gaps effectively, but it may not provide sufficient structural support
Solution Approach 1:
Different resin portions are assigned different melt viscosities based on their functional requirements. The first resin portion has lower melt viscosity for effective gap filling and conformal contact with the electrode plate, while the second resin portion has higher melt viscosity to provide structural support. This spatial differentiation of material properties resolves the contradiction between gap filling and structural support.
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
The design effectively suppresses electrolytic solution leakage, enhances the module's reliability by preventing corrosion and short-circuiting, and improves impact resistance through the use of modified polyphenylene ether for the second resin portion.
Implementation Method 1
When the first resin portion is welded to the edge portion of the bipolar electrode, the state of the first resin portion changes from a melted state to a solidified state such that the first resin portion is solidified and shrinks
Implementation Method 2
the state of the first resin portion changes from a melted state to a solidified state such that the first resin portion is solidified and shrinks
Data Source
AI summary
A power storage module includes an electrode laminate in which bipolar electrodes are laminated and a sealing body formed of a resin. The bipolar electrode includes an electrode plate, a positive electrode provided on one surface of the electrode plate, and a negative electrode provided on another surface of the electrode plate. The sealing body is provided on a side surface of the electrode laminate to surround an edge portion of the bipolar electrode. The sealing body includes a first resin portion and a second resin portion. The first resin portion is welded to the edge portion of the bipolar electrode. The second resin portion surrounds the first resin portion from an outer side along the side surface. A mold shrinkage factor of the first resin portion is lower than a mold shrinkage factor of the second resin portion.