Protective-Layer Copper Foil for Curl-Resistant Battery Electrodes
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Solution Overview
Problem
Copper foils used in secondary batteries, particularly those with thin thicknesses, experience curling issues during manufacturing, leading to defects such as tears or wrinkles, which hinder the production of high-capacity and high-performance batteries.
Innovation Solution
A copper foil with a matte and shiny surface, coated with a protective layer containing carbon, nitrogen, and oxygen, is manufactured using a specific electrolytic process with controlled electrolyte composition and additives, including a polishing agent, moderator, and leveling agent, to prevent curling and enhance surface properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If copper foil thickness is reduced to increase battery capacity, then the amount of active materials that can be included increases and battery capacity improves, but curling occurs leading to defects such as tears or wrinkles
Solution Approach 1:
The patent applies parameter changes by carefully controlling the electrolyte composition (copper ion concentration: 70-150 g/L, sulfuric acid: 80-150 g/L, chlorine: 15-25 ppm) and additive concentrations (polishing agent: 1-20 ppm, moderator: 0.1-10 ppm, leveling agent: 1-10 ppm) during electroplating to produce thin copper foils with suppressed curling and improved flatness
Solution Approach 2:
The patent uses composite materials by incorporating multiple organic additives (polishing agent, moderator, and leveling agent) into the electrolyte system to simultaneously achieve smooth surface finish, controlled crystal structure, and suppressed curling in thin copper foils
2Quantity of substance
If copper foil thickness is reduced to increase battery capacity, then the number of current collectors that can be increased, but curling occurs making manufacturing difficult
Solution Approach 1:
The patent changes electrolyte parameters including copper ion concentration (70-150 g/L), sulfuric acid concentration (80-150 g/L), and additive concentrations to produce thin copper foils with controlled physical properties that resist curling and are easier to manufacture
Solution Approach 2:
The patent introduces organic additives as intermediaries in the electroplating process - specifically polishing agents, moderators, and leveling agents - that mediate between the electrolyte and copper deposition to control surface quality and reduce curling tendencies
3Reliability
If electrolytic copper foil is used to improve battery characteristics, then high capacity and stable performance are achieved, but curling occurs during manufacturing
Solution Approach 1:
The patent optimizes electrolyte parameters (copper ions: 70-150 g/L, sulfuric acid: 80-150 g/L, chlorine: 15-25 ppm) and additive concentrations to produce copper foils with controlled crystal structures and surface properties that maintain flatness while ensuring high reliability
Solution Approach 2:
The patent implements feedback control by monitoring and adjusting electrolyte composition and plating conditions to consistently produce copper foils with suppressed curling and controlled surface finish, ensuring both shape stability and performance reliability
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 solution effectively suppresses curling, allowing for the production of high-capacity copper foils that maintain stability and performance, enhancing the manufacturing process and product quality of secondary batteries.
Implementation Method 1
forming a copper film includes allowing a cathode plate and a rotating anode drum disposed to be spaced apart from each other in an electrolyte in an electrolytic cell to conduct current to form the copper film on the rotating anode drum
Data Source
AI summary
One embodiment of the present disclosure provides a copper foil including a copper film having a matte surface and a shiny surface, and a protective layer disposed on the copper film, wherein the copper film includes copper and non-copper elements, and the non-copper elements include carbon (C), nitrogen (N), and oxygen (O).