Cathode Material Recycling with LiOH Regeneration and Low Salt Waste
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Solution Overview
Problem
Current recycling methods for lithium-ion batteries face challenges in achieving quantitative recovery of lithium and other valuable metals due to complex processes and environmental concerns, leading to inefficiencies and high costs, as well as the generation of neutral salt waste and significant CO2 emissions.
Innovation Solution
A method using lithium hydroxide (LiOH) instead of sodium hydroxide (NaOH) for dissolving and processing cathode materials from battery waste, involving leaching, electrolysis, and precipitation to recover lithium and transition metals, thereby reducing neutral salt waste and improving the CO2 footprint.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional recycling methods using sodium hydroxide (NaOH) are employed, then the processing of cathode materials can be achieved, but neutral salt waste is generated and significant CO2 emissions occur
Solution Approach 1:
The patent changes the chemical parameter from sodium hydroxide (NaOH) to lithium hydroxide (LiOH) as the precipitating agent. This parameter change transforms the chemical reaction pathway, converting the harmful neutral salt waste (sodium sulfate) into recoverable lithium sulfate, thereby eliminating the harmful factor while maintaining processing capability
Solution Approach 2:
The patent converts the previously harmful neutral salt waste (sodium sulfate) into a beneficial product (lithium sulfate) that can be further processed. By using LiOH instead of NaOH, the reaction produces lithium sulfate which can be electrolyzed to regenerate LiOH, turning waste into a valuable resource and closing the material cycle
2Quantity of substance
If quantitative recovery of lithium is pursued through conventional methods, then lithium can be recovered, but the process becomes complex and costly
Solution Approach 1:
The patent establishes a continuous cyclic process where lithium sulfate from precipitation is electrolyzed to regenerate LiOH, which is then reused in subsequent precipitation steps. This continuous regeneration eliminates the need for external LiOH supply and achieves quantitative lithium recovery through a self-sustaining cycle, simplifying the overall process
Solution Approach 2:
The system becomes self-sufficient by regenerating its own reagent (LiOH) through electrolysis of the produced lithium sulfate. The process serves itself by converting the byproduct back into the required chemical, eliminating external dependencies and reducing process complexity while achieving complete lithium recovery
3Quantity of substance
If lithium is recovered as lithium carbonate (Li2CO3) by adding sodium carbonate (Na2CO3), then lithium recovery is achieved, but additional neutral salt production occurs and environmental release is problematic
Solution Approach 1:
The patent changes the precipitating agent from sodium carbonate (Na2CO3) to lithium hydroxide (LiOH), which fundamentally alters the reaction product from lithium carbonate plus sodium sulfate waste to lithium sulfate that can be regenerated. This parameter change eliminates the harmful neutral salt load while maintaining quantitative lithium recovery
Solution Approach 2:
Instead of producing harmful neutral salt waste, the patent converts the lithium-containing byproduct into a regenerable resource. The lithium sulfate produced during precipitation becomes the feedstock for LiOH regeneration, transforming a waste stream into a valuable material that sustains the process
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 approach enables efficient and quantitative recovery of cathode materials, minimizing neutral salt waste, reducing energy consumption, and lowering CO2 emissions, while closing the recycling loop for lithium-ion batteries and avoiding the use of sodium in the process.
Implementation Method 1
Dissolving the cathode material from shredded battery waste by treatment with a leaching agent to obtain a cathode material precursor solution
Implementation Method 2
Separating the filtrate obtained in step b) and splitting the filtrate into LiOH and leaching agent by electrolysis
Implementation Method 3
Treating the cathode material precursor solution with LiOH to obtain a solid cathode material precursor mixed hydroxide and a filtrate containing at least the Li salt of the leaching agent
Data Source
Figure 1
AI summary
The present invention relates to a method for producing cathode material from battery waste and to a cathode material obtained according to the method according to the invention.