Bipolar Electrode Sealing Structure for Moisture-Resistant Power Storage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power storage devices face performance degradation due to moisture transmission, which affects their efficiency and reliability.
Innovation Solution
A power storage device design featuring an electrode stack with bipolar electrodes, a separator, and a resin sealing portion that includes a first resin portion, a second resin portion, and an end surface welded portion, where the water vapor transmission rate of the end surface welded portion is lower than that of the adhesive portions, effectively suppressing moisture transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a resin with high adhesion to the current collector is used for the first adhesive portion and second adhesive portion, then the sealing property is improved, but the water vapour transmission rate increases
Solution Approach 1:
The patent applies different resin properties to different parts of the sealing portion. The first adhesive portion and second adhesive portion use resin with high adhesion to the current collector, while the end surface welded portion uses resin with low water vapour transmission rate. This local differentiation of material properties resolves the contradiction by allowing each part to optimize for its specific function.
Solution Approach 2:
The sealing portion is constructed as a composite structure combining multiple resin portions with different characteristics. The adhesive portions provide strong bonding to the current collector, while the end surface welded portion provides moisture barrier functionality. This composite approach allows simultaneous achievement of high adhesion and low water vapour transmission.
2Reliability
If the end surface welded portion has low water vapour transmission rate to suppress moisture transmission, then battery performance is maintained, but the sealing structure becomes more complex
Solution Approach 1:
The sealing portion is segmented into three distinct parts: first adhesive portion, second adhesive portion, and end surface welded portion. Each segment has a specific function and can be optimized independently. This segmentation allows the structure to achieve low water vapour transmission rate while maintaining manufacturability through modular design.
Solution Approach 2:
The end surface welded portion serves multiple functions: it seals the end surface of the battery, provides a moisture barrier with low water vapour transmission rate, and structurally integrates the first and second resin portions. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in device complexity.
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 proposed design effectively suppresses moisture transmission into the battery, thereby maintaining battery performance and preventing degradation caused by moisture ingress.
Implementation Method 1
a water vapour transmission rate of the end surface welded portion is less than a water vapour transmission rate of the first adhesive portion and a water vapour transmission rate of the second adhesive portion
Data Source
AI summary
A power storage device includes an electrode stack including a plurality of electrodes, a separator, and a resin sealing portion. The plurality of electrodes include a bipolar electrode. The bipolar electrode includes a current collector, a positive electrode active material layer, and a negative electrode active material layer. The sealing portion includes a first adhesive portion adhered to the current collector, a second adhesive portion adhered to the current collector, a first reinforcing portion bonded to the first adhesive portion, a second reinforcing portion bonded to the second adhesive portion, and an end surface welded portion. A water vapour transmission rate of the end surface welded portion is less than a water vapour transmission rate of the first adhesive portion and a water vapour transmission rate of the second adhesive portion.