Blended Cathode Recycling via Selective Manganese Phase Leaching
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Solution Overview
Problem
Current recycling methods for lithium-ion batteries, particularly for blended cathode materials, face inefficiencies due to the dissolution of all inorganic components, leading to dilution of waste streams and challenges in separating and regenerating specific phases, which affects the recovery of valuable metals like manganese, cobalt, and nickel.
Innovation Solution
A method involving phase-selective leaching using an acid with a pKa greater than or equal to −2 to selectively remove manganese-containing phases from mixed-phase battery electrode materials, allowing for the separation and regeneration of individual phases, such as LiMn2O4, while leaving other phases like Nickel NMC or NCA intact, using ascorbic acid as both a leaching and reducing agent.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If conventional hydrometallurgy uses strong mineral acids to dissolve all inorganic components, then complete metal recovery is achieved, but the waste streams become diluted and separation of specific phases becomes difficult
Solution Approach 1:
The patent applies selective extraction by using weak organic acids (oxalic, malic, succinic, or lactic acid) to extract only manganese-containing phases from blended cathode materials. This selective extraction leaves other phases (NMC, NCA, LFP) intact, enabling precise phase separation while recovering manganese, thereby resolving the contradiction between complete metal recovery and phase separation precision.
Solution Approach 2:
The patent implements local quality by treating different phases within the blended cathode material differently. The weak organic acid selectively interacts with manganese-containing phases due to their specific chemical properties, while leaving other phases unaffected. This localized chemical action enables precise separation of manganese phases from the blend, solving the contradiction between complete recovery and selective separation.
2Ease of operation
If pyrometallurgy uses high temperatures to smelt batteries, then sorting is not required, but volatile elements are lost and energy consumption increases
Solution Approach 1:
The patent replaces the thermal-mechanical smelting process with a chemical leaching process using weak organic acids. Instead of using high-temperature pyrometallurgy that requires no sorting but consumes大量 energy, the patent uses selective chemical extraction that can be performed on blended materials without sorting, thereby substituting a high-energy mechanical/thermal system with a lower-energy chemical system that achieves the same sorting-free operation while preserving volatile elements.
3Productivity
If conventional leaching uses concentrated mineral acids, then leaching efficiency is improved, but disposal challenges arise and long leaching times are required
Solution Approach 1:
The patent changes the chemical parameters of the leaching system by using weak organic acids (oxalic, malic, succinic, or lactic acid) instead of concentrated strong mineral acids. This parameter change maintains effective leaching of manganese-containing phases while avoiding the harmful disposal issues associated with strong acids. The weak organic acids can be more easily managed and disposed of, reducing environmental harm while maintaining productivity.
Solution Approach 2:
The patent employs weak organic acids that are more environmentally friendly and easier to dispose of compared to concentrated mineral acids. These weak acids can be used in controlled amounts and their disposal presents fewer environmental challenges, effectively replacing expensive and problematic strong acids with cheaper, more sustainable alternatives that reduce harmful factors.
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 the efficient and selective recovery of manganese-containing phases, avoiding dilution of waste streams and allowing for the direct regeneration of NMC phases, thereby improving the recycling efficiency and reducing environmental impact.
Implementation Method 1
the acid acting as both a leaching agent and a reducing agent
Implementation Method 2
treating the mixed-phase battery electrode material with a solution of an acid, the acid acting as both a leaching agent
Data Source
AI summary
A method (2800) of selectively leaching one or more manganese-containing phases from a mixed-phase battery electrode material comprises treating (2802) the mixed-phase battery electrode material with a solution of an acid, the acid acting as both a leaching agent and a reducing agent, so as to form a manganese-containing leachate whilst leaving at least one phase of the battery electrode material unleached, wherein the acid has a pKa greater than or equal to −2. Either or both of the leachate and the remaining electrode material may then be regenerated (2806, 2808).