Metal-Distributed Silicon Oxide Anode Material for Swelling Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Silicon-based active materials in negative electrodes of lithium secondary batteries suffer from volume expansion and contraction during charging and discharging, leading to damage and reduced service life performance.
Innovation Solution
A composite negative electrode active material comprising silicon-based oxide particles with a metal (Li, Mg, or Al) distributed on the surface or inside, with an average aggregate diameter of 65 nm or less, prepared through a method involving heat treatments and gas phase reactions to control volume expansion and contraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If silicon-based active materials are used to achieve high capacity and energy density, then the capacity increases about 10-fold compared to carbon-based materials, but volume expansion and contraction occur during charging and discharging causing damage to active material particles and deterioration in service life characteristics
Solution Approach 1:
The patent applies composite materials by combining silicon-based oxide particles with metal particles (Li, Mg, or Al) to create a composite negative electrode active material. The metal particles are distributed on the surface or inside the silicon-based oxide particles, forming a composite structure that leverages the high capacity of silicon while the metal component helps mitigate volume expansion issues, thereby improving service life characteristics
Solution Approach 2:
The patent changes physical parameters by controlling the average aggregate diameter to be 65 nm or less through specific heat treatment processes. This parameter change in aggregate size affects the material's structural stability during charging and discharging, reducing the harmful effects of volume expansion and contraction while maintaining high capacity
2Use of energy by moving object
If silicon-based active materials are used to achieve high energy density with thin electrodes, then energy density increases, but cracks and damage to active material particles occur due to volume expansion
Solution Approach 1:
The composite structure of silicon-based oxide particles combined with metal particles provides mechanical support and structural stability. The metal particles distributed within or on the surface of the silicon-based oxide particles help prevent crack formation and maintain particle integrity during volume expansion and contraction cycles, preserving active material strength while enabling high energy density
Solution Approach 2:
The patent applies local quality by distributing metal particles specifically on the surface or inside the silicon-based oxide particles. This localized placement of metal particles provides targeted structural reinforcement at critical locations where stress concentration occurs during volume expansion, preventing cracks while maintaining overall particle integrity
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 composite material significantly reduces damage during charging and discharging, improves initial efficiency, and enhances the service life performance of the negative electrode and secondary battery by minimizing volume expansion and contraction.
Implementation Method 1
generating a first vapor by subjecting a silicon-based oxide including a compound represented by the following Chemical Formula 2 to a first heat treatment; generating a second vapor by subjecting a metal including at least one selected from the group consisting of Li, Mg, and Al to a second heat treatment
Implementation Method 2
mixing the first vapor and the second vapor and subjecting the resulting mixture to a gas phase reaction; obtaining a silicon-based oxide-metal composite by cooling after the gas phase reaction
Implementation Method 3
the silicon-based active materials have not been used for general purposes due to the problems of volume expansion caused by charging and discharging
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A composite negative electrode active material including silicon-containing oxide particles; and a metal distributed on the surface, inside, or both on the surface and inside of the silicon-containing oxide particles, in which an average value of aggregate diameters measured by a specific method is 65 nm or less. The composite negative electrode active material can have a uniform and small aggregate diameter to minimize deterioration of service life performance of the composite negative electrode active material caused by volume expansion and contraction of silicon during charging and discharging.