Lignocellulosic Anode Carbon Processing to Prevent Metal Leaching
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Solution Overview
Problem
Current methods for manufacturing anode materials for secondary batteries from lignocellulosic biomass fail to effectively remove trace metal components, which can affect the performance and safety of batteries.
Innovation Solution
A method involving the use of lignocellulosic biomass, where an acid is added to hydrolyze hemicellulose and convert cellulose into microfibrillated cellulose, followed by an aqueous alkaline solution to remove metal components, and then heat-treatment to produce highly crystalline or amorphous carbon materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If biomass-derived carbon materials are used as anode active materials, then cost is reduced and environmental friendliness is improved, but metal components remain in the material which can dissolve into electrolyte and trigger electrochemical reactions affecting performance and safety
Solution Approach 1:
The patent applies preliminary action by performing acid treatment and demineralization processes on the biomass before carbonization. This removes metal components and impurities from the biomass in advance, preventing them from dissolving into the electrolyte later and triggering harmful electrochemical reactions. The acid treatment step specifically targets metal component removal before the material is used as an anode active material.
Solution Approach 2:
The patent converts the harmful effect of metal components in biomass into a benefit by using acid treatment to selectively remove these metals. The acid that would otherwise be seen as a processing step is transformed into a beneficial demineralization agent that eliminates the harmful metal components, turning a potential problem into a solution that improves battery safety and performance.
2Object-affected harmful factors
If conventional gas-phase demineralization process is used to remove metal components, then metal removal is achieved, but the process complexity increases and metal-halogen complexes are difficult to capture and remove
Solution Approach 1:
The patent replaces the complex gas-phase demineralization process with a simpler liquid-phase acid treatment method. Instead of using gas-phase chemistry that requires complex equipment for capturing and removing metal-halogen complexes, the invention uses liquid acid treatment that directly dissolves and removes metal components through washing, significantly simplifying the overall process.
Solution Approach 2:
The patent changes the phase parameter from gas-phase to liquid-phase demineralization. This parameter change transforms the complex gas-phase process requiring metal-halogen complex capture into a simpler liquid-phase acid treatment where metals are removed through dissolution and washing, reducing process complexity while maintaining effective metal removal.
3Stability of the object's composition
If graphite coated with non-graphitic carbon is used to mitigate delamination, then delamination is reduced, but capacity decreases compared to graphitic materials
Solution Approach 1:
The patent changes the structural parameter of the carbon material by controlling the carbonization process to produce a carbonized biomass material with optimized structure. This parameter change allows the material to achieve both structural stability (preventing delamination) and high capacity, overcoming the trade-off between using pure graphite (high capacity but delamination) or non-graphitic carbon (stable but lower capacity).
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 method produces anode materials with high specific capacity and charge-discharge efficiency, while significantly reducing carbon dioxide emissions and ensuring the removal of residual metal components.
Implementation Method 1
adding an acid to lignocellulosic biomass to hydrolyze at least a portion of the hemicellulose within the lignocellulosic biomass with the concomitant conversion of at least a portion of the cellulose into microfibrillated cellulose
Implementation Method 2
adding an aqueous alkaline solution to the lignin-microfibrillated cellulose complex-containing hydrolyzed reaction product obtained in step (a) to further remove residual acidic components and water-soluble metal components
Implementation Method 3
heat-treating the ground solid particles of the lignin-microfibrillated cellulose complex obtained in step (c) to modify at least a portion of the solid particles into a crystalline or amorphous carbon material
Data Source
Figure 1(a)~1(b)
Figure 2
Figure 3a~4(e)
AI summary
Disclosed herein is a method for manufacturing an anode material for secondary batteries from lignocellulosic biomass, wherein the metal components contained in the biomass do not leach into the electrolyte, thereby contributing to improved performance and enhanced stability when the anode material is applied to a secondary battery material.