Spent Li-Ion Battery Anode Recycling for Dispersed Graphene
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Solution Overview
Problem
The recycling of lithium-ion battery anodes is inefficient, with current methods being costly and environmentally harmful, and there is a shortage of graphite due to its limited supply, which hinders the production of high-quality graphene for lithium-ion batteries.
Innovation Solution
A method involving acid leaching with a hydrogen peroxide and sulfuric acid solution, followed by a hydrothermal process using sodium hydroxide, and then a shear mixing process enhanced by hydrogen passivation to produce high-quality dispersed graphene from spent lithium-ion battery anodes, effectively removing impurities and expanding graphene plane layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If current recycling methods are used for lithium-ion battery anodes, then some graphite can be recovered, but the process is costly and environmentally harmful
Solution Approach 1:
The patent changes the chemical parameters of the leaching solution by using sulfuric acid combined with hydrogen peroxide instead of traditional cyanide or strong oxidizing agents. This parameter change achieves effective impurity removal while being environmentally friendly and cost-effective, directly resolving the contradiction between graphite recovery and environmental harm
Solution Approach 2:
The patent replaces mechanical crushing and physical separation methods with chemical leaching and hydrothermal treatment. This substitution achieves more complete graphite purification and recovery while reducing energy consumption and environmental impact, addressing both the quantity recovery and environmental harm aspects
2Quantity of substance
If current recycling methods are used for lithium-ion battery anodes, then some graphite can be recovered, but the cost is high
Solution Approach 1:
The patent uses readily available chemicals (sulfuric acid, hydrogen peroxide, sodium hydroxide) at optimized concentrations to achieve effective graphite recovery. This parameter optimization reduces material costs while maintaining high recovery efficiency, directly addressing the cost contradiction
Solution Approach 2:
The patent employs self-cleaning and self-purification mechanisms where the chemical solutions automatically remove impurities through leaching and hydrothermal treatment without requiring additional expensive processing steps. This self-service approach reduces operational costs while achieving high graphite recovery
3Quantity of substance
If graphite is obtained from limited supply sources, then production requirements can be met, but supply accessibility is restricted
Solution Approach 1:
The patent recovers graphite from discarded lithium-ion battery anodes through systematic chemical processing. This transforms waste materials into valuable graphite supply, expanding accessibility beyond traditional mining sources and meeting production requirements sustainably
Solution Approach 2:
The patent creates a universal graphite supply system that can process various types of spent battery anodes regardless of their original source or composition variations. This multi-functional approach enhances supply accessibility by accepting diverse waste inputs and producing standardized graphite products
4Manufacturing precision
If acid leaching solution is applied to remove impurities from expanded graphite, then purification is achieved, but chemical impurities require multiple removal steps
Solution Approach 1:
The patent merges the leaching and hydrothermal treatment steps into an integrated process where sulfuric acid with hydrogen peroxide performs both initial impurity removal and prepares the graphite for subsequent hydrothermal purification. This merging reduces the number of separate process steps while achieving high purification precision
Solution Approach 2:
The patent uses parameter changes in the hydrothermal treatment step (temperature, pressure, pH control) to selectively remove different types of impurities in sequence. This parameter optimization achieves comprehensive purification while minimizing the number of required process steps
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 significantly reduces costs and environmental impact while producing high-quality graphene with improved properties, addressing the graphite supply issue and enabling efficient recycling of lithium-ion battery anodes, which can enhance the performance of new batteries and support a circular economy.
Implementation Method 1
applying an acid leaching solution to an anode of a lithium-ion battery to produce expanded graphite
Implementation Method 2
the acid leaching solution includes a hydrogen peroxide solution and a sulfuric acid solution
Implementation Method 3
applying a hydrothermal process to the expanded graphite to produce purified graphite
Implementation Method 4
subjecting the purified graphite to a shear mixing process combined with a hydrogen passivation process to produce dispersed graphene
Implementation Method 5
the hydrogen passivation process applies hydrogen gas to facilitate the graphene exfoliation and dispersion
Data Source
AI summary
Methods and systems for producing graphene from spent lithium-ion batteries are disclosed. One method includes applying an acid leaching solution to an anode of a lithium-ion battery to produce expanded graphite, applying a hydrothermal process to the expanded graphite to produce purified graphite, and subjecting the purified graphite to a shear mixing process to produce dispersed graphene. In some examples, the shear mixing process is combined with a hydrogen passivation process, which collectively improves each of graphene quality, graphene conversion rate, and graphene production efficiency.