Battery Metal Recovery Using Hydrobromic Acid and Bromate Separation
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Solution Overview
Problem
Current hydrometallurgical methods for recovering metals from spent lithium-ion batteries, particularly lithium and transition metals, face inefficiencies and require auxiliary reducing agents like hydrogen peroxide, especially when dealing with manganese-containing cathode materials.
Innovation Solution
The use of hydrobromic acid for reductive leaching of cathode materials, which generates elemental bromine that can be absorbed and used to form bromate for oxidative precipitation of manganese, allowing for efficient separation of metals without additional reducing agents, and subsequent precipitation of lithium carbonate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If hydrochloric acid is used for leaching metals from spent lithium-ion batteries, then metal dissolution can be achieved, but additional auxiliary reducing agents like hydrogen peroxide are required to improve leaching efficiency
Solution Approach 1:
The patent employs hydrobromic acid that automatically generates bromine in situ during the leaching process, which then serves as the reducing agent to convert Co3+ to Co2+. This self-generating reducing capability eliminates the need for external auxiliary reducing agents like hydrogen peroxide, thereby improving leaching efficiency while simplifying the overall process
Solution Approach 2:
The patent changes the chemical parameter from hydrochloric acid to hydrobromic acid, which fundamentally alters the leaching mechanism. Hydrobromic acid has stronger reducing capability and can directly reduce Co3+ to Co2+ during leaching, significantly improving metal dissolution efficiency without requiring additional reducing agents
2Reliability
If hydrochloric acid is used for leaching, then metal recovery can be achieved, but the process requires multiple auxiliary reagents and steps
Solution Approach 1:
Hydrobromic acid serves dual functions: as the leaching agent to dissolve metals and as the source of bromine that acts as the reducing agent. This self-sufficient system ensures reliable metal recovery while eliminating the need for multiple auxiliary reagents and simplifying the manufacturing process
Solution Approach 2:
The patent merges the leaching function and reducing function into a single reagent system. Hydrobromic acid simultaneously performs metal dissolution and generates bromine for reduction, combining multiple functions that would otherwise require separate reagents and steps
3Reliability
If conventional leaching methods are used, then metal dissolution occurs, but separation of lithium and transition metals requires multiple precipitation steps
Solution Approach 1:
The patent changes the chemical environment by using hydrobromic acid leaching, which produces bromine and subsequently bromate. The bromate generated in situ serves as a selective oxidizing agent that enables efficient separation of lithium from transition metals through controlled precipitation, reducing the number of separation steps required
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 achieves higher yields in metal recovery, particularly for manganese, and provides a more manageable process design, enabling effective separation and purification of lithium and transition metals from spent lithium-ion batteries.
Implementation Method 1
hydrobromic acid accomplishes the reductive leaching of cathode materials with good yield absent auxiliary reducing agent such as hydrogen peroxide
Implementation Method 2
elemental bromine - the co-product of the reductive leaching reaction - can be absorbed in an alkaline solution, e.g., sodium hydroxide, to form bromide and bromate
Implementation Method 3
The so-formed bromate has been shown to be an effective precipitation reagent for divalent metals such as Mn2+
Implementation Method 4
precipitation of lithium in the form of the carbonate salt from the aqueous phase
Data Source
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AI summary
The invention relates to hydrometallurgical method for recovering metals from spent energy storage devices. The method comprises combining aqueous hydrobromic acid leach solution and an electrode material of spent energy storage devices in a reaction vessel, dissolving the metals contained in the electrode material to form soluble metal bromide salts, removing elemental bromine, if formed, from the reaction vessel, separating insoluble material, if present, from the leach solution to obtain a metal-bearing solution and isolating one or more metals from said metal-bearing solution.