Dual-Insulation Member for Rechargeable Battery Short Circuit Prevention
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Solution Overview
Problem
Rechargeable batteries with aluminum cases are prone to short circuits due to deformation under external forces, and synthetic resin films used for insulation can melt or deform, compromising electrical insulation.
Innovation Solution
A dual-insulation member system with a first and second insulation portion that projects from the first insulation portion, forming a stop for the cap plate and covering two sides of the electrode assembly, providing enhanced mechanical stability and insulation, even under deformation, and minimizing space to improve energy density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a synthetic resin film is installed between the case and the electrode assembly to prevent short circuits, then insulation performance is improved, but the film may melt or deform under heat and electrolyte exposure, compromising insulation reliability
Solution Approach 1:
The insulation member is constructed as a composite structure combining a synthetic resin film layer with an additional insulation layer (such as a porous layer or mesh structure). This composite design provides both chemical resistance to electrolyte and thermal stability, while maintaining electrical insulation properties. The multiple layers work together to prevent short circuits even when exposed to heat and electrolyte over time.
Solution Approach 2:
The patent modifies the physical and chemical parameters of the insulation member by selecting materials with specific glass transition temperatures, melting points, and chemical resistance properties. The insulation member is designed to maintain its mechanical and electrical properties across the operating temperature range and chemical environment, preventing degradation that would lead to short circuits.
2Ease of manufacture
If the case is made of aluminum for excellent formability and electrical conductivity, then manufacturing ease is improved, but the case deforms under external force causing short circuits between the electrode assembly and case
Solution Approach 1:
The insulation member serves as an intermediary element positioned between the aluminum case and the electrode assembly. This intermediate layer provides the necessary electrical insulation to prevent short circuits while allowing the aluminum case to maintain its superior formability and manufacturing advantages. The insulation member absorbs the mechanical stress and deformation, protecting the electrical components.
Solution Approach 2:
The insulation member is designed with a segmented or multi-layer structure that includes different functional layers: a primary insulation layer for electrical isolation, a mechanical support layer for structural integrity, and potentially a sealing layer. This segmentation allows each layer to optimize its specific function while working together to solve the contradiction between case formability and insulation reliability.
3Ease of manufacture
If the cap plate is adhered to the case with heat, then assembly is simplified, but the heat deforms the synthetic resin film reducing insulation performance
Solution Approach 1:
The insulation member is pre-installed and securely positioned between the case and electrode assembly before the cap plate adhesion process. This preliminary placement ensures that the insulation member is already in its correct position and orientation, protecting it from heat-induced deformation during the subsequent cap plate bonding process. The insulation member acts as a pre-established protective barrier.
Solution Approach 2:
The insulation member is designed with sufficient thickness and mechanical strength to withstand the heat and pressure applied during cap plate adhesion. This beforehand cushioning effect protects the synthetic resin film from deforming or melting during the assembly process, maintaining its insulation integrity even when exposed to thermal stress from the adhesive curing process.
Data Source
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AI summary
The invention relates to a rechargeable battery (100) with a case (26), an electrode assembly (10) in the case (26) and an insulation member (70) between the electrode assembly (10) and the case (26). In order to facilitate assembly and increase operation safety of the rechargeable battery (100), the insulation member (70) comprises a first insulation portion (71) and a second insulation portion (72) protruding from the first insulation portion (71).