Microporous Copper Foil Electrolysis for Uniform Pore Formation

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Solution Overview

Problem

Current methods for producing microporous copper foils face challenges such as inconsistent micropore size, non-uniform distribution, and poor surface quality, leading to issues like copper deposition, deformation, and reduced tensile strength, which affect the production efficiency and quality of lithium-ion batteries.

Innovation Solution

An electrolytic deposition method involving a copper sulfate electrolyte with specific additives like chloride ions, brightener, leveling agent, and wetting agent, along with controlled masking and anti-oxidation treatment, to produce microporous copper foils with consistent micropore size, uniform distribution, and high tensile strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the electrolytic deposition method is used to produce microporous copper foil, then the production efficiency and quality consistency are improved, but the risk of abnormalities such as copper deposition on pore walls, micropore deformation, and color differences increases if parameters are not well controlled

Engineering Contradiction:
Improvemicropore size consistency and distribution uniformityVSAvoidprocess stability and defect rate
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent optimizes key process parameters including copper ion concentration (40-80 g/L), temperature (20-40°C), and current density (30-60 A/dm²) to achieve stable micropore formation. By precisely controlling these parameters within specific ranges, the method ensures consistent micropore size and distribution while minimizing defects such as copper deposition on pore walls and color differences.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements process monitoring and control mechanisms to detect and adjust parameters during electrolytic deposition. This feedback system ensures that deviations from optimal conditions are corrected in real-time, maintaining process stability and preventing abnormalities such as micropore deformation and inconsistent foil quality.

Inventive Principle:
Principle #23Feedback

2Productivity

If copper ion concentration is increased to improve deposition rate, then productivity increases, but excessive copper ion deposition on micropore walls occurs, causing adhesion issues and edge tearing

Engineering Contradiction:
Improvedeposition rateVSAvoidfoil tensile strength and edge integrity
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The patent identifies and optimizes the copper ion concentration parameter, setting it within the range of 40-80 g/L. This optimized concentration range enables sufficient deposition rate for productive manufacturing while preventing excessive copper ion accumulation on micropore walls that would cause adhesion problems and edge tearing during separation.

Inventive Principle:
Principle #35Parameter changes

3Weight of moving object

If the copper foil is made thinner to reduce weight, then the energy density of lithium-ion batteries is improved, but the mechanical strength and handling reliability of the copper foil deteriorates

Engineering Contradiction:
Improvecopper foil weightVSAvoidcopper foil mechanical strength
Core Design Contradiction:
Weight of moving objectVSStrength

Solution Approach 1:

The patent employs microporous copper foil structure with controlled porosity (30-70%) to achieve weight reduction while maintaining mechanical strength. The micropore architecture reduces the amount of copper material needed, lowering the foil weight for reduced battery weight, while the porous network structure provides sufficient mechanical integrity and handling reliability.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent produces composite-structured microporous copper foil with optimized pore distribution and wall thickness. This composite architecture combines lightweight properties with enhanced mechanical strength, allowing thin foils to maintain sufficient handling reliability and structural integrity during battery manufacturing and operation.

Inventive Principle:
Principle #40Composite materials

4Weight of moving object

If oxidative etching method is used to create micropores, then the copper foil weight is reduced, but the pore size and porosity become difficult to control due to oxide film changes over time

Engineering Contradiction:
Improvecopper foil weightVSAvoidpore size and porosity control
Core Design Contradiction:
Weight of moving objectVSManufacturing precision

Solution Approach 1:

The patent replaces the chemical oxidative etching process with an electrolytic deposition approach. This substitution eliminates the problem of oxide film changes over time that make pore size and porosity control difficult. The electrolytic method provides precise, real-time control over micropore formation through electrical parameters, ensuring consistent manufacturing precision while achieving weight reduction.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 method achieves microporous copper foils with uniform micropore distribution, smooth surfaces, and enhanced tensile strength up to 300 MPa, improving battery performance and reducing manufacturing costs by minimizing copper deposition and pipeline issues.

Implementation Method 1

The electrolytic deposition method involves pre-treating and masking the cathode substrate, and depositing the microporous copper foil on the cathode substrate via the current

Methodology Applied
Scientific EffectElectrolysis: Electrolysis

Implementation Method 2

introducing a steam, so that copper undergoes oxidation and reacts with sulfuric acid to generate a copper sulfate solution

Methodology Applied
Scientific EffectOxidation: Oxidation

Data Source

PatentEP4636136A1Electrolytic method for preparing microporous copper foil
Publication Date: 2025.10.22 JIUJIANG TELFORD ELECTRONICS MATERIAL CO LTD
  • EP4636136A1 patent drawingFigure 1~2
  • EP4636136A1 patent drawingFigure 3
  • EP4636136A1 patent drawing

AI summary

An electrolytic method for preparing a microporous copper foil, comprising the following steps: according to process proportions, adding a copper raw material, together with sulfuric acid and deionized water, into a copper dissolving tank for mixing; introducing stream so that copper is oxidized and reacts with the sulfuric acid to generate a copper sulfate solution; filtering the copper sulfate solution to obtain a copper sulfate electrolyte; and adding the copper sulfate electrolyte into an electrolyte tank. By preparing the copper sulfate electrolyte and adding a required copper foil additive into the copper sulfate electrolyte, a microporous copper foil having uniform and evenly-distributed micropores and a bright foil surface is obtained.