Bipolar Stack Insulating Frame Layout to Prevent Air Traps
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Solution Overview
Problem
Bipolar stacked batteries face issues with air trapping during formation, leading to potential electrical shorts and uneven current distribution, which can cause premature degradation and reduced voltage output.
Innovation Solution
Incorporating an electrically and ionically insulating frame between battery cells that does not fully seal the edges, ensuring the insulating frame is positioned to prevent air entrapment and maintain structural integrity, with specific area and thickness ratios to avoid deformation and shorts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an insulating frame is used to prevent electrical shorts, then reliability is improved, but air trapping occurs during formation leading to delamination and bubble formation
Solution Approach 1:
The insulating frame is designed with differentiated local properties: it provides complete insulation at critical edges where electrical shorts are most likely to occur, while maintaining controlled openness in specific regions to allow air escape during battery formation. This localized quality differentiation resolves the contradiction between ensuring electrical isolation and preventing air trapping.
Solution Approach 2:
The insulating frame acts as an intermediary structure between the current collector and external environment, mediating between the need for electrical isolation and the need for air permeability during formation. The frame's specific geometric design allows it to fulfill both functions simultaneously by providing insulation where needed while maintaining air pathways.
2Reliability
If the insulating frame completely seals the battery cell edges, then electrical insulation is improved, but air cannot escape during formation causing delamination
Solution Approach 1:
Instead of complete sealing, the insulating frame implements partial sealing that provides sufficient electrical insulation while deliberately leaving air escape pathways open. This partial action approach prevents the harmful effect of air trapping while maintaining the necessary electrical isolation function.
3Power
If joint parts are used to connect batteries in series, then voltage output is improved, but volumetric loss and additional resistance occur reducing power density
Solution Approach 1:
The bipolar battery design merges multiple battery units into a stacked configuration where current collectors serve dual functions as both electrical conductors and structural support elements. This merging eliminates the need for separate joint parts, thereby maintaining voltage output while reducing volumetric loss and minimizing additional resistance.
Solution Approach 2:
The current collector in the bipolar battery design performs multiple functions simultaneously: it serves as an electrical conductor for current transport, a structural support element for mechanical stability, and a thermal management component. This multi-functionality replaces traditional single-function joint parts, improving power density by eliminating redundant components.
4Ease of manufacture
If current collectors from different layers come into contact, then manufacturing simplicity is improved, but electrical short circuits occur reducing voltage
Solution Approach 1:
The insulating frame segments the battery cell into distinct stacked layers, creating physical boundaries between current collectors from different layers. This segmentation maintains manufacturing simplicity by allowing straightforward stacking while preventing direct contact between current collectors that would cause electrical shorts, thereby preserving voltage output.
Data Source
Figure 1A~1B
Figure 2~3
Figure 4
AI summary
A bipolar stacked battery that prevents air from becoming trapped during formation of the bipolar stacked battery has a plurality of stacked battery cells. An electrically and ionically insulating frame is formed between each of the plurality of stacked battery cells.