Flexible Battery Packaging Structure for Bending Fatigue Life
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Solution Overview
Problem
Current flexible batteries face manufacturing inefficiencies due to complex winding processes, are prone to damage during bending, and have short bending fatigue life due to conventional encapsulation materials, leading to safety issues and performance degradation.
Innovation Solution
A battery design featuring a stacked electrode assembly with strip-shaped coating and empty foil areas, a rigid first packaging layer, and a second packaging layer that reduces stress concentration and accommodates deformation, along with a protective housing to enhance strength and safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If conventional aluminum plastic film encapsulation material is used, then the battery can be manufactured with standard materials, but the bending fatigue life is short affecting battery service life
Solution Approach 1:
The patent uses a composite packaging structure consisting of an aluminum plastic film packaging layer and a rubber packaging layer. The aluminum plastic film provides barrier properties while the rubber layer provides flexibility and stress absorption during bending, creating a composite material system that resolves the contradiction between standard manufacturing materials and extended bending fatigue life.
Solution Approach 2:
The patent changes the physical parameters of the packaging material by introducing a rubber layer with different mechanical properties (higher elasticity and stress tolerance) compared to conventional aluminum plastic film alone. This parameter change enables the packaging to withstand repeated bending cycles, extending the bending fatigue life while maintaining reliable battery service life.
2Strength
If the battery is made rigid to maintain structural integrity, then strength is improved, but the battery body is prone to damage during bending causing safety issues
Solution Approach 1:
The patent applies different material properties to different parts of the battery structure. The electrode plates and separator maintain their structural integrity, while the packaging layers (particularly the rubber layer) are designed with local flexibility to accommodate bending. This local quality differentiation allows the battery to maintain overall strength while resisting damage during bending operations.
3Quantity of substance
If multiple cells are connected in parallel to increase capacity, then the battery can serve intelligent wearable products, but the difficulty in synchronous winding increases leading to low production efficiency
Solution Approach 1:
The patent merges multiple electrode plates and separators into a single integrated electrode assembly structure. Instead of separately winding multiple cells and then connecting them in parallel (which causes synchronous winding difficulties), the invention combines them into one unified assembly that can be packaged as a single unit, thereby maintaining increased battery capacity while significantly improving production efficiency.
Data Source
AI summary
An electrode assembly includes a first electrode plate, a separator, and a second electrode plate that are disposed in a stack. The first electrode plate and the second electrode plate respectively have coating areas and empty foil areas arranged at intervals. Centers of the coating areas overlap each other to form a coating portion of the electrode assembly, and centers of the empty foil areas overlap each other to form a flexible portion of the electrode assembly. The first packaging layer coats the coating portion and the flexible portion of the electrode assembly, and the second packaging layer at least coats the first packaging layer on the flexible portion.