Battery Electrode Binder and Carbon Coating for Stronger Adhesion
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Solution Overview
Problem
Existing electrodes lack sufficient peel strength between the active material layer and the current collector, limiting their performance in batteries.
Innovation Solution
An electrode design featuring a block copolymer binder with a weight average molecular weight of 170,000 or more, containing aromatic rings, and a conductive carbon coating layer on the current collector, enhancing adhesion and peel strength through interactions between the aromatic rings and conductive carbon.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional binders are used in the active material layer, then the electrode structure is simple and easy to manufacture, but the peel strength between the active material layer and the current collector is insufficient
Solution Approach 1:
The patent changes the molecular weight parameter of the block copolymer binder to 170,000 or more, which is significantly higher than conventional binders. This parameter change enhances the binder's adhesion capability and peel strength without requiring complex structural modifications to the overall electrode design
Solution Approach 2:
The patent uses a block copolymer consisting of multiple blocks (first block with aromatic rings, second block, and third block with aromatic rings) as a composite molecular structure. This composite polymer structure provides both strong adhesion to the current collector and good binding capability for active material particles, resolving the contradiction between strength and complexity
2Strength
If a conductive carbon coating layer is added to the current collector, then the peel strength and adhesion are improved, but the manufacturing process becomes more complex
Solution Approach 1:
The conductive carbon coating layer is applied in advance to the current collector surface before the active material layer is formed. This preliminary action ensures that the adhesion enhancement and conductivity improvement are already in place before electrode assembly, simplifying the overall manufacturing process despite the additional coating step
Solution Approach 2:
The conductive carbon coating layer serves multiple functions simultaneously: it enhances adhesion between the current collector and active material layer, provides electrical conductivity, and prevents corrosion of the current collector substrate. This multi-functionality reduces the need for separate components, offsetting the added manufacturing complexity
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
Significantly improves the peel strength between the active material layer and the current collector, leading to enhanced battery output and durability.
Implementation Method 1
the aromatic ring included in the block copolymer of the binder in the active material layer and the conductive carbon in the coating layer interact with each other. This interaction improves the adhesion between the active material layer and the current collector
Implementation Method 2
the aromatic ring included in the block copolymer of the binder in the active material layer and the conductive carbon in the coating layer interact with each other
Data Source
AI summary
An electrode includes an active material layer that includes an active material, a solid electrolyte, and a binder and a current collector that includes a substrate and a coating layer coating the substrate and being in contact with the active material layer. The binder includes a block copolymer that includes two first blocks constituted of a repeating unit having an aromatic ring and a second block located between the two first blocks. The weight average molecular weight of the block copolymer is 170,000 or more. The coating layer includes conductive carbon.