Nanoscale Composite Anode Material for Lower Irreversible Capacity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The amorphous materials produced by existing methods for negative electrode active materials in lithium-ion secondary batteries exhibit high irreversible capacity and low utilization rate of the active phase.
Innovation Solution
A composite material is developed with an active phase dispersed in an amorphous material phase, where the active phase has a particle diameter of 10 nm or less, and the amorphous material phase contains elements A, O, and C, with A being Si, Sn, Ti, Al, or Mg, produced through a method involving reduction of an organometallic compound followed by firing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If existing methods are used to produce amorphous materials for negative electrodes, then the materials can be manufactured, but they exhibit high irreversible capacity and low utilization rate of the active phase
Solution Approach 1:
The invention segments the negative electrode material into distinct phases: an amorphous material phase containing Si, O, and C, and a dispersed active phase consisting of nanoscale particles (10 nm or less). This segmentation allows the amorphous phase to provide structural stability while the segmented active phase particles maximize lithium reaction sites, thereby increasing utilization rate and reducing irreversible capacity losses associated with bulk amorphous materials.
Solution Approach 2:
The invention applies local quality by creating regions with different compositions and structures within the negative electrode material. The amorphous Si-O-C phase provides a stable matrix, while the dispersed active phase particles (containing elements like Si, Sn, Ti, Al, or Mg) provide high lithium reactivity. This local differentiation optimizes both structural integrity and electrochemical performance, resolving the contradiction between manufacturability and utilization efficiency.
2Productivity
If the active phase particle size is reduced to enhance utilization rate, then the reactivity with lithium improves, but the manufacturing complexity increases
Solution Approach 1:
The invention employs preliminary action by incorporating the active phase particles into the amorphous material phase during the manufacturing process itself, rather than requiring separate post-processing steps. The active phase particles are dispersed within the amorphous Si-O-C matrix during formation, which simplifies manufacturing while achieving the desired nanoscale dispersion and high utilization rate.
Solution Approach 2:
The invention uses composite materials by combining the amorphous Si-O-C phase with the active phase containing nanoscale particles. This composite structure integrates the benefits of both phases: the amorphous phase provides structural stability and ease of manufacturing, while the nanoscale active phase particles deliver high lithium reactivity and utilization rate, thereby resolving the contradiction between simplified manufacturing and enhanced performance.
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
This composite material enhances the utilization rate of the active phase, reducing irreversible capacity and improving the reactivity with lithium.
Implementation Method 1
a first step of reducing an organometallic compound, to obtain an intermediate containing an active phase having a median diameter measured by dynamic light scattering spectroscopy of 10 nm or less
Implementation Method 2
a second step of firing the intermediate, to obtain a composite material containing an amorphous material phase and the active phase dispersed in the amorphous material phase
Data Source
Figure 1
Figure 2~4
Figure 5~6
AI summary
A negative electrode material for secondary batteries includes a composite material. The composite material contains an active phase that is reactive with Li, and an amorphous material phase. The active phase is dispersed in the amorphous material phase, and has a particle diameter of 10 nm or less. The amorphous material phase contains elements A, O, and C, and the element A is at least one selected from the group consisting of Si, Sn, Ti, Al, and Mg.