Doped LMO Sorbent Composition for High-Capacity Lithium Loading
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Solution Overview
Problem
Existing methods struggle to produce lithium manganese oxide (LMO) sorbents at commercial scales with high loading capacities and structural integrity, often using lower-grade reactants that reduce the sorbent's effectiveness and impact the spinel structure.
Innovation Solution
A method involving the use of higher-grade reactants, controlled calcination processes at specific temperatures and durations, and doping with agents like Al(OH)3 or Ni-based compounds to enhance the loading capacity and structural stability of LMO sorbents, including multiple calcination steps and milling to achieve desired compositions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If commercial-scale manufacturing uses lower-grade reactants to reduce cost, then manufacturing cost decreases, but loading capacity and structural integrity of LMO sorbent deteriorate
Solution Approach 1:
The patent changes the chemical composition parameters of the reactants by using higher-grade materials with controlled impurity levels. Specifically, it uses manganese compounds with ≥71% Mn content and controlled Fe content (≤0.7%), along with lithium compounds of specified purity, to ensure the resulting LMO sorbent achieves the required loading capacity while maintaining cost-effectiveness for commercial-scale production.
Solution Approach 2:
The patent creates a composite dopant system combining multiple elements (Al, Ni, Co, Mn) in specific ratios within the LMO spinel structure. This composite doping approach enhances both the loading capacity and structural stability of the sorbent, resolving the contradiction between using lower-cost reactants and maintaining high performance.
2Reliability
If higher-grade reactants are used to improve loading capacity, then loading capacity increases, but manufacturing cost increases
Solution Approach 1:
The patent optimizes the chemical composition parameters by specifying precise purity ranges for reactants (e.g., Mn ≥71%, Fe ≤0.7%, Li compounds ≥99.5%) and dopant ratios (e.g., Al: 0.1-1.0%, Ni: 0.1-1.0%). This parameter control ensures high loading capacity while avoiding excessive costs by defining practical minimum specifications rather than requiring maximum purity materials.
Solution Approach 2:
The patent applies doping elements at specific local concentrations within the LMO crystal structure (e.g., Al doping at 0.1-1.0% and Ni doping at 0.1-1.0% molar ratios). This localized quality enhancement at critical sites within the material achieves high loading capacity without requiring high-grade reactants throughout the entire material, thus controlling manufacturing cost.
3Stability of the object's composition
If calcination temperature and duration are increased to improve structural integrity, then structural integrity improves, but energy consumption increases
Solution Approach 1:
The patent optimizes the calcination parameters by specifying a temperature range of 500-550°C and duration of 2-15 hours, with a preferred embodiment of 525°C for 5 hours. This parameter optimization achieves complete phase transformation to LMO spinel structure and ensures structural integrity while minimizing energy consumption compared to conventional higher temperature treatments.
Solution Approach 2:
The patent performs preliminary mixing and doping of reactants before calcination to ensure homogeneous distribution of dopants (Al, Ni, Co, Mn) throughout the precursor blend. This preliminary action ensures uniform phase transformation during calcination, allowing the process to complete at lower temperatures and shorter durations, thus reducing energy consumption while maintaining structural integrity.
4Manufacturing precision
If multiple calcination steps are performed to achieve desired composition, then composition precision improves, but manufacturing time increases
Solution Approach 1:
The patent combines the dopant incorporation and phase transformation steps into a single calcination treatment at 500-550°C for 2-15 hours. This merged process simultaneously achieves complete conversion of precursors to LMO spinel phase and proper incorporation of dopant elements, eliminating the need for separate doping and calcination steps, thus reducing manufacturing time while maintaining composition precision.
Solution Approach 2:
The patent performs preliminary homogeneous mixing and uniform distribution of dopants in the precursor blend before the single calcination step. This preliminary action ensures that the subsequent single calcination treatment achieves complete phase transformation and uniform dopant incorporation, eliminating the need for multiple calcination cycles and reducing overall manufacturing time while maintaining high composition precision.
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
The method results in LMO sorbents with enhanced lithium loading capacities, up to 24.0 mg/g, and improved structural integrity suitable for large-scale direct lithium extraction systems.
Implementation Method 1
calcining the doped precursor blend for an initial calcining duration and first temperature, forming a doped intermediate-state sorbent blend
Implementation Method 2
cooling the doped intermediate-state sorbent blend
Implementation Method 3
milling the doped intermediate-state sorbent blend
Implementation Method 4
reacting the precursor blend with a doping agent to form a doped precursor blend
Data Source
AI summary
Embodiments of the present disclosure may include the synthesis of a doped sorbent spinel material, suitable for cost-effective and industrial-scale extraction of a metal from a metal-containing fluid. Embodiments of the present disclosure further include preparing a doped precursor blend followed by calcining the doped precursor blend for optimal duration and temperature to obtain a mass of intermediate-state sorbents having constituents synthesized at desired percentages. Some embodiments may also include cooling and milling the product obtained. The doped intermediate-state sorbents include desired proportions of Mn3O4, Mn2O3, and lithium manganese oxide (LMO). In some embodiments, the doped LMO may be activated with an acid treatment. Doped LMOs obtained by the method of the present disclosure result in an enhanced loading capacity compared to undoped LMOs formed under similar temperatures and durations.