Battery Electrode Protective Layer for Weld Dust Insulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In secondary battery electrode assemblies, the melt bonding process for current collectors can lead to the expansion of air or low-melting-point substances during welding, resulting in the scattering of molten metal as dust, which may cause internal short circuits due to winding deviations or contact between electrodes.
Innovation Solution
The electrode design includes a conductive adhesive layer, a mixture layer, and an insulating protective layer with a resin, where the protective layer is applied on exposed parts to prevent dust adherence and ensure insulation, reducing the risk of internal short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If melt bonding (resistance welding or laser beam welding) is used to bond lead wire or current collector to collector plate, then bonding strength is improved, but dust is generated due to volume expansion of molten metal causing internal short circuit
Solution Approach 1:
An insulating protective layer is introduced as an intermediary between the current collector and the electrode mixture layer. This protective layer serves as a barrier that prevents dust generated during melt bonding from adhering to the electrode, while still allowing the bonding process to proceed effectively. The protective layer is removed after bonding, having fulfilled its protective function during the welding process.
Solution Approach 2:
The insulating protective layer is applied in advance before the melt bonding process. This preliminary action ensures that the surface is protected from dust contamination before the harmful bonding process occurs, preventing dust adhesion rather than attempting to remove it afterward.
2Ease of manufacture
If dust remains attached to electrode during melt bonding, then manufacturing process is simplified, but internal short circuit occurs due to dust causing electrical connection between electrodes
Solution Approach 1:
The insulating protective layer acts as a temporary intermediary that allows the manufacturing process to proceed without complex dust removal steps, while simultaneously ensuring electrical insulation during the critical bonding phase. After bonding, the protective layer is removed, leaving a clean surface without requiring additional cleaning operations.
Solution Approach 2:
The protective layer converts the potentially harmful dust generation issue into a beneficial process feature. The dust that would normally cause short circuits is prevented from adhering to the electrode, and the protective layer itself can be easily removed after serving its protective purpose, turning a manufacturing challenge into a straightforward process step.
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
The proposed design effectively suppresses the occurrence of internal short circuits by preventing dust adherence and maintaining insulation between electrodes, even in cases of winding deviation or separator misalignment.
Implementation Method 1
an adhesive layer disposed on the core member and being conductive
Implementation Method 2
a protective layer containing a resin and being insulating
Data Source
AI summary
A positive electrode that is an example of an electrode for a secondary battery comprises: a positive electrode core material, a conductive adhesive layer disposed on the positive electrode core material, and a positive electrode mixture layer disposed on the adhesive layer, wherein: the positive electrode core material has, at one end in the short direction of the positive electrode core material, an exposed part on which the adhesive layer and the positive electrode mixture layer are not provided; an insulating protective layer containing a resin is disposed on the exposed part at the one end; and the protective layer is in contact with the end surface at one end of the adhesive layer and the positive electrode mixture layer in the short direction.