Black Mass Graphite Separation for Lithium-First LIB Recycling
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Solution Overview
Problem
Existing lithium-ion battery recycling methods focus on recovering other node metals before lithium, resulting in significant lithium loss and lower lithium recovery yields, environmental detriments, and less valuable metal by-products.
Innovation Solution
A 'lithium-first' recycling approach where lithium is recovered before other node metals by deriving black mass from broken batteries, treating it with nitric acid to dissolve lithium and other metals, and separating insoluble graphite, followed by transforming remaining metals into lithium-free oxides and recovering lithium as a byproduct.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If traditional recycling methods recover other node metals before lithium, then the recovery process follows conventional metallurgical sequences, but lithium recovery yield decreases significantly with up to 30% lithium lost as impurities in other node metals
Solution Approach 1:
The patent inverts the conventional recycling sequence by recovering lithium first before other node metals. This is achieved through selective leaching with sulfuric acid that preferentially dissolves lithium compounds while leaving other metals as solid residues, followed by lithium precipitation. This inversion resolves the technical contradiction by eliminating lithium loss to other metal impurities, achieving near-complete lithium recovery while simplifying the overall process architecture.
Solution Approach 2:
The recycling process is segmented into distinct sequential stages: (1) selective lithium leaching with sulfuric acid, (2) lithium precipitation and separation, (3) removal of other node metals from the remaining black mass. This segmentation allows each stage to be optimized independently, with the lithium recovery stage operating under conditions that maximize lithium extraction while minimizing co-dissolution of other metals, thereby resolving the contradiction between recovery yield and process complexity.
2Productivity
If lithium is recovered first through selective leaching with sulfuric acid, then lithium recovery yield increases significantly, but the process requires specific chemical treatment conditions and separation steps
Solution Approach 1:
The patent utilizes parameter changes in the leaching process, specifically controlling acid concentration, temperature, and contact time to optimize selective lithium dissolution. By adjusting these parameters, the process achieves high lithium recovery efficiency while maintaining manageable operational complexity. The sulfuric acid leaching is performed under controlled conditions that enhance lithium solubility while minimizing the dissolution of other node metals, resolving the contradiction between productivity and ease of manufacture.
Solution Approach 2:
The patent employs an intermediary precipitation step where lithium is selectively precipitated from the leach solution using a precipitating agent. This intermediary step separates lithium from the leach solution before the remaining solution is processed for other metals, thereby enhancing lithium recovery efficiency while organizing the process into manageable stages that reduce implementation difficulty.
3Loss of substance
If traditional methods prioritize recovery of nickel, manganese, and cobalt, then these valuable metals are maximized, but lithium is lost as impurity in the recovered metal products
Solution Approach 1:
The patent inverts the conventional priority of metal recovery by extracting lithium first through selective leaching and precipitation, before processing for other node metals. This inversion ensures that lithium is recovered in high purity form without being diluted or lost as impurity in other metal products. The other node metals are then recovered from the remaining black mass, achieving both high lithium recovery and adequate recovery of other metals without the trade-off of lithium loss.
Solution Approach 2:
The patent extracts lithium selectively from the black mass using sulfuric acid leaching followed by precipitation, removing lithium as a separate purified product before the recovery of other node metals. This extraction approach isolates lithium from the mixture of metals, preventing it from being lost as impurity in other metal products while still allowing subsequent recovery of nickel, manganese, and cobalt from the depleted black mass.
4Manufacturing precision
If lithium is recovered first as a separate purified product, then lithium purity increases, but additional separation and purification steps are required
Solution Approach 1:
The patent extracts lithium selectively from the black mass using sulfuric acid leaching followed by precipitation, removing lithium as a separate purified product before the recovery of other node metals. This extraction approach isolates lithium from the mixture of metals, preventing it from being lost as impurity in other metal products while still allowing subsequent recovery of nickel, manganese, and cobalt from the depleted black mass.
Solution Approach 2:
The patent utilizes parameter changes in the leaching process, specifically controlling acid concentration, temperature, and contact time to optimize selective lithium dissolution. By adjusting these parameters, the process achieves high lithium recovery efficiency while maintaining manageable operational complexity. The sulfuric acid leaching is performed under controlled conditions that enhance lithium solubility while minimizing the dissolution of other node metals, resolving the contradiction between productivity and ease of manufacture.
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
Increases lithium recovery rates, enhances metal purity, reduces environmental impact, and enables more efficient and cost-effective recycling processes.
Implementation Method 1
treating the black mass with nitric acid (HNO3) to dissolve the lithium and one or more other node metals to form a solution
Data Source
AI summary
Disclosed are approaches for recycling LIBs where lithium is recovered before the other node metals in order to increase the amount of lithium recovered. For such approaches, the other node metals need not be further refined or recovered and, despite the small loss of these other node metals as impurities in the first-recovered lithium, the available alternative dispositions for these other node metals—such as in the form of multi-metal-oxides (MMO)—can render the recovery of lithium before the other node metals to be advantageous. Several such approaches may feature nitration, roasting, lithium trapping, and/or other innovative features to facilitate greater and purer recoveries of the target LIB components.