Silicon Oxide Anode Particles With Solvent-Free Carbon Coating
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Solution Overview
Problem
Existing methods for manufacturing silicon-based negative electrode materials, such as TW 1636614 B, are time-consuming and costly due to the use of acetone, which increases material costs and requires procedures like ground pitch dissolution, ultrasonic oscillation, and suction filtration, making mass production difficult.
Innovation Solution
A method involving mixing silicon oxide granules with pitch powder without liquid organic solvents and heating the mixture at a controlled rate to carbonize the pitch, forming a carbon film on the granules, thereby producing negative electrode material particles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If acetone is used to dissolve ground pitch for coating carbon film on silicon/silicon carbide material, then a carbon film can be formed on the material surface, but the manufacturing process becomes time-consuming and costly due to multiple steps including dissolution, ultrasonic oscillation, stirring, and suction filtration
Solution Approach 1:
The invention extracts and eliminates the organic solvent (acetone) from the manufacturing process. Instead of using acetone to dissolve pitch followed by filtration, the patent directly uses pitch powder mixed with binder solution, eliminating the need for dissolution, ultrasonic oscillation, and suction filtration steps while still achieving effective carbon film coating.
Solution Approach 2:
The invention changes the physical state and form of the carbon coating material from dissolved pitch in acetone to solid pitch powder. This parameter change transforms the process from a liquid-based coating method requiring filtration to a solid-liquid mixture method that can be directly applied without complex separation steps.
2Stability of the object's composition
If ground pitch is dissolved in acetone to obtain pitch material, then the pitch can be uniformly distributed, but the material cost increases and the manufacturing process becomes complex requiring multiple processing steps
Solution Approach 1:
The invention removes acetone and the dissolution step from the process. Pitch powder is directly mixed with binder solution containing conductive carbon black, achieving uniform distribution without requiring dissolution, ultrasonic oscillation, or suction filtration equipment and procedures.
Solution Approach 2:
The invention merges the pitch coating function with the conductive additive function by combining pitch powder directly with conductive carbon black in the binder solution. This consolidation eliminates separate dissolution and filtration steps while achieving both uniform pitch distribution and conductive network formation.
3Manufacturing precision
If multiple processing steps including ultrasonic oscillation and suction filtration are performed, then the carbon film coating can be achieved, but the time required for manufacturing increases significantly
Solution Approach 1:
The invention extracts and eliminates time-consuming steps including ultrasonic oscillation and suction filtration. The process proceeds directly from mixing pitch powder with binder solution to heating and carbonization, reducing the manufacturing cycle while maintaining coating quality through the simplified solid-liquid mixing approach.
Solution Approach 2:
The invention establishes a continuous manufacturing process where pitch powder is mixed with binder solution and directly heated for carbonization without interruption for filtration or solvent removal. This continuous action eliminates idle time between steps while maintaining effective carbon film formation.
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 method reduces material and time costs by eliminating the need for organic solvents, facilitating efficient mass production while achieving superior performance in lithium-ion batteries, including enhanced fast charging and discharging capabilities and improved cycle life.
Implementation Method 1
heating the mixture at a heating rate ranging from 0.65° C./min to 1.25° C./min to a carbonization temperature of not lower than 600° C. for not less than 5 hours, so that the thus melted pitch is carbonized
Implementation Method 2
the thus melted pitch is carbonized and forms a carbon film on a surface of each of the silicon oxide granules
Data Source
AI summary
A method for manufacturing negative electrode material particles includes the steps of: mixing silicon oxide granules with a powder of a pitch without using any liquid organic solvents, so as to obtain a mixture; and heating the mixture at a heating rate ranging from 0.65° C./min to 1.25° C./min to a carbonization temperature of not lower than 600° C. for not less than 5 hours, so that the thus melted pitch is carbonized and forms a carbon film on a surface of each of the silicon oxide granules, thereby obtaining the negative electrode material particles. Each of the negative electrode material particles has a mean particle size ranging from 2 μm to 11 μm.