Laminated Battery Current Collector for Thin-Foil Strength
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current collectors for batteries, particularly those used in lithium ion secondary batteries and nickel-hydrogen batteries, face challenges in achieving sufficient strength to prevent breakage and tears during production, especially when thinned for increased capacity.
Innovation Solution
A current collector with a laminate structure comprising at least a first metal layer and a second metal layer, where the laminate interface between the two layers has a roughness Ra of 0.12 or greater, providing enhanced tensile strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the current collector is thinned to increase battery capacity, then the battery capacity increases, but the strength of the current collector decreases leading to deformation or breakage
Solution Approach 1:
The current collector employs a laminated structure comprising a copper foil base layer and a nickel plating layer. This composite material approach combines the high ductility and electrical conductivity of copper with the high strength and corrosion resistance of nickel, achieving both thinness for capacity and sufficient strength to prevent breakage during production and use.
Solution Approach 2:
The invention optimizes specific parameters including the thickness of the copper foil (5-15 μm), the thickness of the nickel plating layer (1-5 μm), and the roughness of the laminate interface (Ra ≥ 0.12 μm). These parameter changes enable the thin current collector to achieve adequate strength while maintaining electrical performance and preventing breakage during production.
2Quantity of substance
If the current collector is thinned to increase active material amount, then the amount of active materials increases, but the strength enough to suppress breakage and tears during production is insufficient
Solution Approach 1:
The laminated copper-nickel structure provides enhanced reliability during production. The nickel plating layer forms a robust protective shell that resists mechanical damage such as breaks and tears during handling and assembly, while the thin overall structure allows for maximum active material loading.
Solution Approach 2:
By controlling the interface roughness (Ra ≥ 0.12 μm) and optimizing layer thicknesses, the invention achieves superior bonding between layers and enhanced mechanical integrity. This ensures the current collector maintains sufficient strength to withstand production processes while being thin enough to maximize active material content.
3Strength
If a multiple layer structure using nickel film is formed to improve strength, then the strength as current collector is improved, but the concrete interlayer structure for achieving high level strength is not disclosed
Solution Approach 1:
The current collector is segmented into two distinct functional layers: a copper foil base layer providing ductility and electrical conductivity, and a nickel plating layer providing strength and corrosion resistance. This segmentation allows each layer to perform its optimal function while maintaining a relatively simple overall structure.
Solution Approach 2:
Different regions of the current collector have different properties: the copper foil base layer has high ductility and electrical conductivity, while the nickel plating layer has high strength and corrosion resistance. The interface between layers has controlled roughness (Ra ≥ 0.12 μm) to enhance bonding. This local quality differentiation achieves high strength without excessive structural complexity.
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 proposed solution achieves a high tensile strength exceeding theoretical values by optimizing the roughness of the laminate interface, thereby addressing the issue of breakage and tears during production.
Implementation Method 1
a laminate interface between the first metal layer and the second metal layer has a roughness Ra≥0.12
Implementation Method 2
The proposed solution achieves a high tensile strength exceeding theoretical values by optimizing the roughness of the laminate interface
Data Source
AI summary
[Object]To provide a current collector for battery, having a strength sufficient to suppress breakage and tears during production feared in association with thinning, and a battery having the current collector.[Solving Means]The current collector for battery according to the present invention has at least a first metal layer containing at least a metal selected from Cu, Fe, and Ni, and a second metal layer laminated on the first metal layer and containing at least a metal selected from Cu, Fe, and Ni other than the metal of the first metal layer. One of the first metal layer and the second metal layer contains the Ni, and a laminate interface between the first metal layer and the second metal layer has a roughness Ra≥0.12.