Spray-Dried Alloy Composite Negative Electrode Material
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Solution Overview
Problem
Current methods for preparing alloy composite negative electrode materials for lithium ion batteries, such as the reverse microemulsion method, face challenges with low yield, scalability issues, pollution, and difficulty in recovering surfactants, making them unsuitable for large-scale production and efficient battery performance due to volume expansion and electrochemical deterioration.
Innovation Solution
A process involving spray-drying of a solution containing organic polymer and nanometric precursor compounds, followed by calcination in a neutral atmosphere, to produce a carbon matrix with homogeneously distributed alloy particles, allowing for a scalable and cost-effective production of alloy composite negative electrode materials with improved electrochemical performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the reverse microemulsion method is used to prepare alloy composite negative electrode material, then the metal or metal alloy particles are homogeneously distributed in a carbon matrix structure, but the yield is low and it is difficult to achieve scale production
Solution Approach 1:
The invention changes the fundamental parameters of the preparation method by replacing the reverse microemulsion technique with a spray-drying carbothermal reduction method. This involves changing the physical state (from liquid microemulsion to aerosol spray), the chemical environment (from aqueous to controlled atmosphere), and the processing parameters (temperature, time, and reactant ratios) to achieve both homogeneous distribution and high productivity
Solution Approach 2:
The invention replaces the complex mechanical mixing and ultrasonic vibration steps of the reverse microemulsion method with a spray-drying process that uses aerodynamic forces to achieve homogeneous distribution. The spray-drying technique substitutes mechanical agitation with fluid dynamics to disperse metal precursor particles uniformly throughout the carbon matrix precursor
2Manufacturing precision
If the reverse microemulsion method is used to prepare alloy composite negative electrode material, then the spherical metal bearing carbon matrix structure is obtained, but it is difficult to recover the surfactant and results in pollution and wastes
Solution Approach 1:
The invention extracts and eliminates the surfactant component entirely from the preparation process. By replacing the reverse microemulsion method with spray-drying carbothermal reduction, the harmful surfactant is completely removed from the system, preventing pollution and waste recovery issues while maintaining the ability to form spherical structures through the aerosolization and controlled reduction process
Solution Approach 2:
The invention replaces the expensive and environmentally problematic surfactant with inexpensive, environmentally benign materials such as metal oxide precursors and carbon sources that can be readily disposed of or recycled without environmental harm. The spray-drying process uses simple aerosol carriers that evaporate completely, leaving no harmful residues
3Quantity of substance
If alloy negative electrode material is used in lithium ion batteries, then large specific capacity and high lithium intercalation potential are achieved, but volume expansion during charging and discharging results in pulverization and loss of electric contact
Solution Approach 1:
The invention embeds alloy particles within a carbon matrix structure, creating a nested configuration where the carbon matrix acts as a protective shell around the active alloy material. This nested structure allows the high-capacity alloy to expand and contract during lithium insertion/extraction while the carbon matrix maintains structural integrity and prevents pulverization
Solution Approach 2:
The invention creates a composite material system combining alloy particles with a carbon matrix. This composite structure integrates the high specific capacity of the alloy with the structural stability and electrical conductivity of carbon, achieving both high capacity and reliability during battery cycling. The composite nature allows the carbon to compensate for the alloy's volume expansion issues
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 process enables the production of alloy composite negative electrode materials with enhanced electrochemical performance, suitable for large-scale industrial production, and alleviates volume expansion issues during charge and discharge, maintaining high capacity retention over multiple cycles.
Implementation Method 1
spray-drying said solution whereby a A- and M-precursor bearing polymer powder is obtained
Implementation Method 2
calcining said powder in a neutral atmosphere at a temperature between 500 and 1000°C for 3 to 10 hours whereby, in this carbothermal reduction, a carbon matrix is obtained bearing homogeneously distributed A-M alloy particles
Implementation Method 3
in this carbothermal reduction, a carbon matrix is obtained bearing homogeneously distributed A-M alloy particles
Data Source
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AI summary
The present invention relates to a process for preparing an alloy composite negative electrode material having a spherical carbon matrix structure for lithium ion batteries by spray-drying carbothermal reduction. The invention covers a process for preparing a negative electrode material for a lithium ion battery with a general formula A-M/Carbon, wherein A is a metal selected from the group consisting of Si, Sn, Sb, Ge and Al; and wherein M is different from A and is at least one element selected from the group consisting of B, Cr, Nb, Cu, Zr, Ag, Ni, Zn, Fe, Co, Mn, Sb, Zn, Ca, Mg, V, Ti, In, Al, Ge; and comprising the steps of: - providing a solution comprising an organic polymer and either chemically reducible nanometric A- and M-precursor compounds, or nanometric Si and a chemically reducible M-precursor compound, when said metal A is Si; - spray-drying said solution whereby a A- and M-precursor bearing polymer powder is obtained, and - calcining said powder in a neutral atmosphere at a temperature between 500 and 1000° C for 3 to 10 hours whereby, in this carbothermal reduction, a carbon matrix is obtained bearing homogeneously distributed A-M alloy particles.