Battery Electrode Binder Layer Porosity for Adhesion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The production of battery electrodes faces challenges with adhesion between the current collector and the active material layer due to convection during drying, leading to increased interfacial resistance and decreased battery performance.
Innovation Solution
A method involving the sequential lamination of a binder layer and an active material layer onto a current collector, where microbubbles are mixed into the binder solution to create pores that enhance adhesion and reduce interfacial resistance by forming an electrically conductive path.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a binder layer containing a binder is provided between a current collector and an active material layer to enhance adhesion, then adhesion between the current collector and active material layer is improved, but electrical resistance between the current collector and active material layer increases
Solution Approach 1:
The binder layer is designed with a porous structure containing numerous pores, which provides pathways for electrical conduction between the current collector and active material layer. The porosity allows electrical current to pass through the binder layer while the binder matrix maintains adhesion between layers.
Solution Approach 2:
The binder layer is formed as a composite structure combining a binder matrix with a porous network. This composite structure simultaneously provides both adhesive function (through the binder) and electrical conduction function (through the pores), resolving the contradiction between adhesion and electrical resistance.
2Productivity
If a paste-like active material layer-forming material is coated onto a current collector and dried by applying hot air, then the active material layer is formed, but convection during drying causes binder to rise to the surface layer, decreasing adhesion between the current collector and mixture layer
Solution Approach 1:
A binder layer is formed on the current collector before coating the active material layer. This preliminary binder layer serves as an adhesive interface that prevents binder migration during subsequent drying of the active material layer, ensuring strong adhesion between the current collector and the final electrode structure.
Solution Approach 2:
The electrode structure is segmented into distinct functional layers: a binder layer for adhesion, and an active material layer for electrochemical function. This segmentation allows the binder layer to perform its adhesive function without being disrupted by convection during drying of the active material layer.
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 method improves adhesion between the current collector and the active material layer while maintaining low interfacial resistance, resulting in high-performance battery electrodes with superior output characteristics and cycle durability.
Implementation Method 1
a binder layer and an active material layer are sequentially laminated on a current collector... mixing microbubbles into a binder solution containing a binder... forming a binder solution layer by imparting the bubble-containing binder solution to a current collector
Implementation Method 2
forming a binder solution layer by imparting the bubble-containing binder solution to a current collector... depositing the binder solution layer and a paste layer onto the current collector by imparting an active material layer-forming paste containing an active material onto the binder solution layer... obtaining an electrode in which a binder layer and an active material layer are formed on the current collector
Data Source
AI summary
The electrode production method provided by the present invention includes a step of mixing microbubbles 52 into a binder solution 50 containing a binder, a step of forming a binder solution layer 56 by imparting the bubble-containing binder solution 50 to a current collector 10, a step of depositing the binder solution layer 56 and a paste layer 36 on the current collector 10 by imparting an active material layer-forming paste containing an active material 32 over the binder solution layer 56, and a step of obtaining an electrode in which a binder layer and an active material layer are formed on the current collector 10 by drying both the deposited binder solution layer 56 and the paste layer 36.