Secondary Battery Electrode Plate Protrusion Protection
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Solution Overview
Problem
The existing secondary battery electrode plates face issues with current passing performance and safety due to deformation and cracking of protrusion portions during the rolling process, leading to potential short circuits and reduced energy density.
Innovation Solution
Incorporating a first protective layer with greater hardness than the conductive layer, positioned on the protrusion portion of the electrode plate, which supports and protects the protrusion from deformation, and a conductive structure with extending portions to enhance current guiding and prevent short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the active material layer is applied to the conductive layer and then rolled to make the active material layer thinner, then the energy density is increased, but the protrusion portion of the conductive layer is likely to be bent and crack due to deformation mismatch, degrading current passing performance
Solution Approach 1:
The patent applies a protective layer to the protrusion portion of the conductive layer before the rolling process. This preliminary protective measure prevents the protrusion portion from cracking during subsequent rolling operations, ensuring current passing performance is maintained while still achieving the desired thinning of the active material layer to increase energy density.
Solution Approach 2:
The protective layer acts as a cushioning element applied in advance to the protrusion portion. This cushioning layer absorbs and distributes the stress during rolling, preventing direct transmission of deformation forces to the conductive layer that would cause cracking, thus protecting current passing performance while enabling energy density improvement through rolling.
2Reliability
If a multilayer current collector structure is adopted to improve safety performance, then the safety performance is improved, but the device complexity increases
Solution Approach 1:
Instead of making the entire current collector structure complex, the patent applies the protective layer locally only to the protrusion portion where it is most needed for safety. This localized approach improves safety performance at the critical current collection point without unnecessarily complicating the overall current collector structure.
Solution Approach 2:
The patent creates a composite structure by combining the conductive layer with a protective layer material that has complementary properties. This composite approach enhances safety performance by adding protective functionality to the conductive layer, while the layered composite structure remains manageable in complexity.
Data Source
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AI summary
The present disclosure provides a secondary battery and an electrode plate. The electrode plate includes a current collector, an active material layer, and a first protective layer. The current collector includes an insulating layer and a conductive layer disposed on the insulating layer. The conductive layer has a main body portion covered by the active material layer and a protrusion portion uncovered by the active material layer. The first protective layer is disposed on a side of the protrusion portion facing away from the insulating layer. The electrode plate further includes a conductive structure, which has a connecting portion fixed on the main body portion, and a first extending portion exceeding an end of the protrusion portion away from the main body portion. The first protective layer is disposed on a side of the connecting portion close to the active material layer along a height direction.