Coating Formulation for Battery Electrodes Using Composite Resin
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Solution Overview
Problem
Conventional coatings on metal surfaces, such as aluminum, exhibit insufficient solvent resistance and adhesion issues, leading to peeling, flaking, and high contact resistance in battery and capacitor electrode plates, which affect their performance and lifespan.
Innovation Solution
A coating formulation comprising a polar solvent, hydroxyl-containing resin, and organic acid or its derivative, specifically polyvinyl acetal resin, ethylene-vinyl alcohol copolymer, modified/unmodified polyvinyl alcohol, and cyanoethylated polymer, is used to create a binder that crosslinks during heating, enhancing adhesion and solvent resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional resin coatings are applied on metal surfaces, then adhesion to metal surfaces is achieved, but solvent resistance is insufficient
Solution Approach 1:
The patent uses a composite binder system combining polyvinyl acetal resin with silicone-modified polyvinyl alcohol resin. This composite material approach allows the coating to achieve both strong metal surface adhesion through the polyvinyl acetal component and excellent solvent resistance through the silicone-modified polyvinyl alcohol component, resolving the contradiction between adhesion and solvent resistance
Solution Approach 2:
The patent modifies the chemical structure of polyvinyl alcohol by introducing silicone groups and controlling the acetal content within specific ranges (silicone-modified polyvinyl alcohol with 20-80% saponification degree). These parameter changes enable the resin to simultaneously provide good adhesion and high solvent resistance, transforming a single-property material into a dual-function binder
2Strength
If coating formulation is applied to electrode plate, then adhesion to collector is improved, but contact resistance becomes high
Solution Approach 1:
The patent optimizes the binder composition parameters by using polyvinyl acetal resin with specific acetal content (10-80%) and combining it with silicone-modified polyvinyl alcohol in controlled ratios. These parameter adjustments create a coating that adheres well to the collector while maintaining sufficient electrical conductivity, preventing excessive contact resistance
Solution Approach 2:
The coating formulation creates different functional zones: the polyvinyl acetal resin provides strong adhesion to the metal collector surface, while the silicone-modified polyvinyl alcohol maintains conductivity and flexibility. This local differentiation of material properties within the coating layer resolves the contradiction between adhesion and contact resistance
3Ease of operation
If binder is dissolved in solvent for coating, then coating applicability is achieved, but dissolution into electrolyte occurs
Solution Approach 1:
The patent uses silicone-modified polyvinyl alcohol as an intermediary substance that bridges the requirements for solubility in coating solvents and resistance to electrolyte dissolution. This intermediate resin can be dissolved in the coating formulation for application but forms a resistant barrier once applied, preventing direct contact and dissolution by the battery electrolyte
Solution Approach 2:
The patent controls the saponification degree of the polyvinyl alcohol component within 20-80% and uses specific silicone modifications to create a resin with dual solubility characteristics: soluble in coating solvents for application but resistant to electrolyte penetration, resolving the contradiction between coating applicability and electrolyte stability
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 formulation achieves excellent adhesion and solvent resistance on metal surfaces, improving the performance and longevity of electrode plates by reducing peeling and flaking, and enhancing contact resistance with collectors.
Implementation Method 1
a binder that crosslinks during heating, enhancing adhesion and solvent resistance
Data Source
AI summary
This invention relates to a coating formulation, a coating formulation for manufacturing an electrode plate and an undercoating formulation, and their use. These coating formulations are all characterized by containing, in a polar solvent, a hydroxyl-containing resin and an organic acid and/or a derivative thereof. The hydroxyl-containing resin is at least one of (1) a polyvinyl acetal resin, (2) an ethylene-vinyl alcohol copolymer, (3) a modified and/or unmodified polyvinyl alcohol, and (4) a cyanoethyl-containing polymer. According to the present invention, there is provided a coating formulation capable of forming a coating of excellent adhesion and solvent resistance on a surface of a metal material such as an aluminum material. Also provided are a coating formulation for manufacturing an electrode plate for a battery or a polarizable electrode plate for a capacitor, in which an active material layer has excellent adhesion to a collector made of an aluminum foil, copper foil or the like and is also equipped with excellent electrolyte resistance and improved contact resistance to the collector, an undercoating formulation, the electrode plate and its manufacturing process, the battery, and the capacitor.