Electrode Assembly Insulating Film to Prevent Tab-Housing Contact
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Solution Overview
Problem
In prior cylindrical secondary batteries, the flattened tab part can overlap with the housing, compromising safety performance due to potential contact with the battery's top cover.
Innovation Solution
An electrode assembly design featuring a first insulating film with a connection part and an extension part, where the extension part includes a non-adhesive area to prevent the electrode terminal from lifting and contacting the battery housing, enhanced by a second insulating film for additional insulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the tab part is flattened to improve electrical connection, then electrical conductivity is improved, but the tab part may overlap with the housing which compromises safety performance
Solution Approach 1:
An insulating film is introduced as an intermediary element between the electrode assembly (including the flattened tab part) and the battery housing. This insulating film prevents direct contact between the conductive tab part and the housing, eliminating the short circuit hazard while allowing the tab part to maintain its flattened configuration for good electrical connection.
Solution Approach 2:
A flexible insulating film is used to wrap around the electrode assembly, providing continuous insulation coverage. The thin film structure conforms to the shape of the electrode assembly including the flattened tab part, ensuring that the insulating protection is maintained without interfering with the electrical function or requiring complex rigid structures.
2Reliability
If the insulating film extends beyond the electrode terminal part to ensure insulation, then insulation performance is improved, but the film may cause the electrode terminal to lift and contact the top cover, creating safety issues
Solution Approach 1:
The insulating film is designed with different functional zones: a first insulating film that extends beyond the electrode terminal part to provide insulation coverage, and a second insulating film that is positioned to prevent the terminal from lifting. This local differentiation of film properties and positions ensures both insulation performance and prevention of terminal displacement without causing safety issues.
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
Improves safety performance by preventing the electrode terminal from overlapping with the battery housing, ensuring stable insulation and reducing the risk of short circuits.
Implementation Method 1
the connection part being provided with an adhesive area for connecting with the electrode terminal part
Implementation Method 2
the first insulating film for being wound around the electrode unit... ensure mutual insulation between the electrode assembly and the housing of the secondary battery
Data Source
AI summary
Embodiments of the present disclosure relates to an electrode assembly, a secondary battery, a battery pack and a device. The electrode assembly includes: an electrode unit including an electrode body and an electrode terminal part electrically connected with the electrode body; and a first insulating film for being wound around the electrode unit, the first insulating film including a connection part and an extension part connected with each other, the connection part being provided with an adhesive area for connecting with the electrode terminal part, the extension part being a part of the first insulating film extending beyond an end face of the electrode terminal part, and at least part of the extension part being provided as a non-adhesive area.