CNT Coated Battery Current Collector via Water Transfer
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Solution Overview
Problem
Existing methods for manufacturing electrode current collectors for secondary batteries face challenges in achieving uniform carbon nanotube coating without physical damage, leading to reduced adhesion and increased internal resistance, which affects battery performance.
Innovation Solution
A method involving the preparation of a carbon nanotube dispersion, forming a CNT film on a water surface, and transferring metal foil at a controlled angle and speed to create a uniform CNT coating layer on the current collector, followed by heat treatment to cure the layer, ensuring increased adhesion and conductivity without physical damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a carbon nanotube coating layer is formed on a thin electrode current collector, then adhesion between the current collector and electrode slurry is improved, but the current collector may suffer physical damage
Solution Approach 1:
A polyacrylonitrile (PAN)-based anchor film is introduced as an intermediary layer between the thin current collector and the carbon nanotube coating. This anchor film serves as a mediator that provides mechanical support to the fragile current collector during the coating process, while also enabling strong adhesion to the electrode slurry. The PAN film is applied first, then carbon nanotubes are coated onto it, creating a layered structure where the anchor film protects the current collector from physical damage during handling and coating operations.
2Strength
If etching is performed on the current collector surface to increase adhesion, then specific surface area is increased, but the lifespan of the current collector is reduced
Solution Approach 1:
The polyacrylonitrile-based anchor film serves as a protective intermediary that eliminates the need for etching the current collector surface. Instead of chemically modifying the current collector through etching (which weakens it), the anchor film provides the necessary surface area and chemical functionality for adhesion. This approach increases the specific surface area for electrode slurry attachment while preserving the current collector's structural integrity and extending its lifespan.
3Strength
If silane-based coupling agent or coating solution is applied to increase adhesion, then adhesion between current collector and active material is improved, but internal resistance increases
Solution Approach 1:
The invention applies carbon nanotubes, which are highly conductive materials, specifically at the interface between the current collector and electrode slurry. This local application of conductive material ensures that the adhesion interface maintains excellent electrical conductivity. The carbon nanotubes form a conductive network within the PAN anchor film, ensuring that electrons can efficiently transfer from the current collector through the coating layers to the active material, thereby preventing increase in internal resistance.
Solution Approach 2:
The invention creates a composite coating structure consisting of a polyacrylonitrile-based anchor film combined with carbon nanotubes. This composite material combines the adhesive properties of PAN with the high electrical conductivity of carbon nanotubes. The resulting composite coating layer provides both strong adhesion to the electrode slurry and excellent electrical conductivity, avoiding the internal resistance problem associated with silane-based coupling agents or conventional coating solutions.
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 enables a uniform carbon nanotube coating on the electrode current collector, enhancing adhesion and electrical conductivity, thereby improving battery output characteristics and extending the lifespan of the current collector.
Implementation Method 1
forming a CNT film on water surface by spraying the CNT dispersion onto water
Implementation Method 2
forming a CNT coating layer on metal foil by transferring the metal foil in a roll-to-roll manner after being unwound while passing through the water such that one surface of the metal foil is brought into contact with one end of the CNT film formed on the water surface
Implementation Method 3
curing the CNT coating layer by heat treatment while rewinding the metal foil with the CNT coating layer formed thereon
Data Source
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AI summary
The present invention relates to a method of manufacturing an electrode current collector for a secondary battery and an electrode including an electrode current collector manufactured using the method. In particular, provided herein are a method of manufacturing an electrode current collector for a secondary battery which includes forming a CNT coating layer on a surface of an electrode current collector to increase electrical conductivity, and an electrode including an electrode current collector manufactured according to the method.