Battery Aluminum Foil Composition for Thin High-Ductility Electrodes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing technologies face challenges in manufacturing battery aluminum foils with a thickness not greater than 13 μm, a tensile strength not less than 250 MPa, and an elongation not less than 5%, as they struggle to break the inverse relationship between tensile strength and elongation.
Innovation Solution
A high-ductility battery aluminum foil is developed with specific components and mass fractions, including Si, Fe, Cu, and other elements, along with a method involving double-roller continuous casting-rolling, cold rolling, and foil rolling, which refines grain size and improves mechanical properties without intermediate annealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the aluminum foil is thinned to increase energy density, then the compaction density is improved, but the foil becomes more prone to breaking during compaction
Solution Approach 1:
The patent changes the chemical composition parameters of the aluminum foil by adding specific elements (Mg: 0.01-0.50%, Mn: 0.01-0.50%, Si: 0.01-0.50%, Cu: 0.01-0.30%, Ti: 0.01-0.10%, B: 0.003-0.03%) to improve both strength and elongation simultaneously, breaking the traditional inverse relationship between these properties
Solution Approach 2:
The patent creates a composite aluminum alloy material by combining aluminum with multiple other elements to form a multi-element alloy system that exhibits superior mechanical properties compared to pure aluminum or simple aluminum alloys, achieving both high strength and high elongation
2Strength
If elements such as Mg, Cu, Mn are added to improve tensile strength, then the tensile strength is improved, but the elongation is limited to greater than 2%
Solution Approach 1:
The patent optimizes the concentration parameters of alloying elements within specific ranges (Mg: 0.01-0.50%, Mn: 0.01-0.50%, Si: 0.01-0.50%, Cu: 0.01-0.30%, Ti: 0.01-0.10%, B: 0.003-0.03%) to achieve a balanced improvement in both tensile strength and elongation, with elongation reaching ≥5% while maintaining tensile strength ≥250 MPa
Solution Approach 2:
The patent develops a multi-element aluminum alloy composite material that combines the strengthening effects of multiple elements while maintaining ductility, achieving superior mechanical properties with tensile strength ≥250 MPa and elongation ≥5%
3Strength
If grain refinement is performed to break the inverted relationship between tensile strength and elongation, then both properties are improved, but achieving improvement beyond the ceiling is particularly challenging under industrial production conditions
Solution Approach 1:
The patent changes the chemical composition parameters to enable effective grain refinement that exceeds industrial ceilings, achieving an average grain size of ≤10 μm through the synergistic effect of multiple alloying elements, which enables both high strength and high elongation
Solution Approach 2:
The patent uses boron (B: 0.003-0.03%) and titanium (Ti: 0.01-0.10%) as intermediary elements that facilitate grain refinement and control grain growth, acting as mediators to achieve fine grain structure with average size ≤10 μm that enables superior mechanical properties
Data Source
AI summary
A high-ductility battery aluminum foil and preparation method thereof are disclosed. The high-ductility battery aluminum foil includes a first component and a second component. The first component includes Si, Fe, and Cu. The second component is Al. In a cross-section of the high ductility battery aluminum foil, a presence of iron-containing second phase with an equivalent circular diameter of 0.2˜3 μm is in a range of 1.1×102˜4×104 particles/mm2. A presence of metal intermetallic compounds, with an equivalent circular diameter of 0.2˜3 μm, formed by Si and Cu respectively with Al, is not greater than 1.1×102 particles/mm2. A presence of elemental silicon particles, with an equivalent circular diameter of 0.2˜3 μm, is not greater than 1.1×102 particles/mm2. The high-ductility battery aluminum foil has a thickness not greater than 13 μm, a tensile strength not less than 250 MPa, and an elongation not less than 5%.