Ultrasonic Electroplating of Copper Foil for Thin Battery Anodes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrolytic copper foils used in secondary batteries lack the necessary mechanical properties and isotropy to support high-energy density applications, leading to issues like crumpling and breakage during the cold-pressing process of negative electrode plates.
Innovation Solution
A method for preparing electrolytic copper foils involves placing an anode and cathode in a twin crystal growth agent containing electroplating solution and performing direct current electroplating under specific ultrasonic wave frequency conditions, which promotes the growth of nano-copper microstructures with high preferred orientation for the (111) crystal plane, enhancing isotropy and twin crystal content.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If electrolytic copper foil is made thinner to increase energy density, then the energy density is improved, but the mechanical strength and hardness deteriorate
Solution Approach 1:
The patent applies parameter changes by controlling the electroplating process parameters including current density (3-10 A/dm²), temperature (20-40°C), and adding specific additives (twin crystal growth agents at 10-50 ppm, grain refining agents at 20-80 ppm) to the electroplating solution. These parameter changes enable the production of ultra-thin copper foil (6-12 μm) with enhanced mechanical properties through controlled crystal grain structure and increased twin crystal content, resolving the contradiction between thinness for energy density and mechanical strength.
2Quantity of substance
If electrolytic copper foil is made thinner to increase energy density, then the energy density is improved, but the foil becomes more prone to crumpling and breakage
Solution Approach 1:
The patent modifies process parameters including current density control (3-10 A/dm²), temperature control (20-40°C), and introduces specific chemical additives (twin crystal growth agents and grain refining agents) to achieve fine-grained structure with high twin crystal content. These parameter changes produce ultra-thin copper foil with enhanced ductility and resistance to crumpling and breakage during cold-pressing, enabling high energy density applications with improved reliability.
Solution Approach 2:
The patent creates a composite microstructure within the copper foil by promoting twin crystal formation and fine grain structure through controlled electroplating. The resulting foil contains a composite of twin crystals and fine grains that provides both the thinness needed for high energy density and the mechanical resilience to resist crumpling and breakage, effectively combining contradictory properties.
3Ease of manufacture
If conventional electroplating is used, then the production process is simple, but the copper foil has low twin crystal content and poor isotropy
Solution Approach 1:
The patent applies parameter changes by introducing specific additives (twin crystal growth agents at 10-50 ppm and grain refining agents at 20-80 ppm) to the conventional electroplating solution and controlling electroplating parameters (current density 3-10 A/dm², temperature 20-40°C). These modifications maintain the simplicity of the electroplating process while significantly improving the copper foil microstructure, achieving high twin crystal content (≥60%) and good isotropy without complex additional processing steps.
4Productivity
If high current density electroplating is used to improve production efficiency, then the productivity is improved, but the crystal orientation and isotropy deteriorate
Solution Approach 1:
The patent optimizes the current density parameter to a specific range (3-10 A/dm²) that balances production efficiency with crystal quality. Additionally, the patent introduces twin crystal growth agents and grain refining agents, and controls temperature (20-40°C) to ensure that even at higher current densities, the copper foil develops proper crystal orientation with high (111) plane content and good isotropy. This parameter optimization enables high productivity while maintaining excellent crystal structure.
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 resulting electrolytic copper foils exhibit improved mechanical properties, higher isotropy, and enhanced electrical conductivity, reducing the likelihood of defects during negative electrode plate production and improving overall battery performance.
Implementation Method 1
performing direct current electroplating to obtain the electrolytic copper foil
Implementation Method 2
the electroplating solution is provided with randomly alternating transitions of one or two of an ultrasonic wave at an f11 frequency and an ultrasonic wave at an f12 frequency
Data Source
AI summary
A method for preparing an electrolytic copper foil includes placing an anode and a cathode to be plated in a twin crystal growth agent containing electroplating solution in an electroplating tank, and, under conditions that the electroplating solution is provided with randomly alternating transitions of one or two of an ultrasonic wave at a frequency f11 and an ultrasonic wave at a frequency f12 and one or two of an ultrasonic wave at a frequency f21 and an ultrasonic wave at a frequency f22, performing direct current electroplating to obtain the electrolytic copper foil, wherein f11>40 kHz, 15 kHz<f12≤40 kHz, 0 kHz<f21≤15 kHz, and f22=0 kHz.