Insulation Bag for Secondary Battery Corrosion Prevention
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Solution Overview
Problem
Secondary batteries face challenges in maintaining stability and durability due to insulation tape non-uniformity, leading to potential corrosion and electrical shorts, especially when the electrode assembly is not perfectly insulated from the case.
Innovation Solution
A secondary battery design incorporating an insulation bag made of materials like polyethylene, polypropylene, or polyethylene terephthalate, hermetically sealing the electrolyte and coupled to the cap plate using thermal compression or chemical bonding, with an air insulation layer between the bag and the case to prevent electrolyte contact with the case.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If insulation tape is used to surround the electrode assembly, then the electrode assembly is insulated from the case, but the insulation is non-uniform and imperfect, leading to current leakage and corrosion
Solution Approach 1:
The patent replaces rigid insulation tape with a flexible insulation bag made of thin film material that can conformally wrap around the electrode assembly. This flexible bag provides uniform and complete insulation coverage, eliminating the non-uniformity and gaps inherent in tape-based insulation while maintaining ease of application.
Solution Approach 2:
The insulation bag acts as an intermediary component between the electrode assembly and the case, providing a hermetic barrier that prevents direct contact and potential corrosion. This intermediate layer ensures complete electrical isolation while allowing the electrode assembly to be securely positioned within the case.
2Device complexity
If the electrode assembly is inserted directly into the case, then the battery structure is simple, but the electrode assembly may contact the case causing corrosion and safety issues
Solution Approach 1:
The insulation bag serves as a flexible shell that encloses the electrode assembly, preventing direct contact with the case while adding minimal structural complexity. The thin film material provides effective insulation without significantly increasing the overall battery size or manufacturing complexity.
Solution Approach 2:
The insulation bag is nested around the electrode assembly, which is itself nested within the case. This nested structure allows the insulation bag to be integrated into the existing battery architecture without requiring additional space or complex assembly procedures, maintaining simplicity while improving reliability.
3Reliability
If insulation tape is applied to the electrode assembly, then some insulation is provided, but additional components and assembly steps are required
Solution Approach 1:
The insulation bag combines multiple functions into a single component: it provides electrical insulation, protects the electrode assembly, and can serve as a containment structure for the electrolyte. This merging of functions reduces the number of separate components needed while maintaining or improving insulation effectiveness.
Solution Approach 2:
The flexible insulation bag can be designed as a single integrated component that replaces multiple insulation tape layers and additional protective elements. The thin film construction provides effective insulation with minimal material usage, reducing overall component complexity while ensuring reliable insulation.
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
This design enhances the stability and durability of the secondary battery by preventing electrical shorts and corrosion, ensuring reliable operation and maintaining battery capacity without the need for additional insulation tape.
Implementation Method 1
The insulation bag may be coupled to a bottom surface of the cap plate by at least one of thermal compression, chemical bonding and use of an adhesion member.
Implementation Method 2
The insulation bag may be coupled to a bottom surface of the cap plate by at least one of thermal compression, chemical bonding and use of an adhesion member.
Implementation Method 3
The secondary battery may further include an insulation layer between an inner wall of the case and the insulation bag. The insulation layer may be an air layer.
Data Source
AI summary
A secondary battery having reinforced stability and durability is provided. The secondary battery includes a case having an opening; an electrode assembly in the case with an electrolyte, a cap plate sealing the opening of the case, a terminal assembly electrically connected to the electrode assembly and protruding through the cap plate, and an insulation bag between the electrode assembly and the case to receive the electrode assembly and to hermetically seal the electrolyte.