Aluminum Alloy Anode Composition for Stable Lithium Battery Cycling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The cycle retention ratio of lithium secondary batteries with silicon-containing aluminum alloy anodes tends to decrease due to the destruction of the aluminum crystal structure caused by the large volume expansion and contraction of silicon during lithium occlusion and release.
Innovation Solution
An anode formed from an aluminum alloy containing Al, at least one element M1 (such as Si, Ge, Sn, Pb, or C), and at least one element M2 (such as Sr, Na, Sb, Ca, Te, Ba, Li, or K), with specific mass ratios and precipitated particles, is used to improve the cycle retention ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a silicon-containing aluminum alloy is used as the anode active material to increase theoretical capacity, then the battery capacity is improved, but the cycle retention ratio decreases due to crystal structure destruction from volume expansion and contraction
Solution Approach 1:
The invention changes the chemical composition parameters of the aluminum alloy by adding specific elements (M1 from C, Si, Ge, Sn, or Pb group and M2 from Sr, Na, Sb, Ca, Te, Ba, Li, or K group) within defined concentration ranges. This modifies the alloy's physical and chemical properties to reduce volume change during lithium occlusion/release, thereby improving cycle retention while maintaining capacity
Solution Approach 2:
The invention creates a composite aluminum alloy material combining multiple elements (Al + M1 + M2) where each element contributes specific properties. The composite structure leverages the high capacity of silicon-containing materials while using M2 elements to suppress volume expansion, achieving both high capacity and good cycle stability
2Reliability
If the aluminum alloy contains precipitated particles to refine crystal grains, then the cycle retention ratio is improved, but the manufacturing precision requirements increase due to specific particle size and density constraints
Solution Approach 1:
The invention specifies precise parameter ranges for precipitated particles (size: 1-10 μm² with number density ≤5000/mm², and size ≥10 μm² with number density ≤500/mm²). By controlling these parameters within defined boundaries, the alloy achieves refined crystal grains that improve cycle retention while providing clear manufacturing targets
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 anode design enhances the cycle retention ratio of lithium secondary batteries by refining the crystal grains of the anode active materials, suppressing volume expansion and contraction, and maintaining high corrosion resistance.
Implementation Method 1
An anode containing a silicon-containing aluminum alloy occludes and releases lithium and expands and contracts during charging and discharging
Implementation Method 2
the aluminum alloy contains precipitated particles containing the element M1 in an alloy matrix
Data Source
AI summary
This anode for a lithium secondary battery is formed of an aluminum alloy containing Al, at least one element M1 selected from the group consisting of C, Si, Ge, Sn, and Pb, and at least one element M2 selected from the group consisting of Sr, Na, Sb, Ca, Te, Ba, Li, and K, in which a ratio of a mass of the element M1 to a total mass of the aluminum alloy is 0.01 mass % or more and 8 mass % or less, and a ratio of a total mass of the element M2 to the total mass of the aluminum alloy is more than 0.001 mass % and 1.0 mass % or less.