Lithium Manganese Nickel Spinel Cathode Without NOx Calcination
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Solution Overview
Problem
Existing processes for preparing lithium manganese oxide spinel compounds for lithium ion batteries generate toxic NOx gases, necessitating costly and dangerous exhaust gas treatment, and lack high capacity and good cyclability.
Innovation Solution
A process involving the use of Mn-, Ni-, and optionally M-containing precursors, where M is Al, Mg, Ti, Co, or Cr, to prepare lithium manganese nickel spinel compounds without generating NOx gases, achieved through milling and calcination, resulting in high-capacity and cyclable spinel compounds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If metal nitrate precursors are used to prepare lithium manganese oxide spinel compounds, then the spinel compounds can be formed, but toxic NOx gases are generated requiring costly and dangerous exhaust gas treatment
Solution Approach 1:
The invention changes the chemical composition parameters of the precursor materials from metal nitrates to metal carbonates, hydroxides, or oxides. This parameter change in the precursor chemistry eliminates the formation of NOx gases during calcination, as these alternative precursors decompose to CO2, H2O, or O2 instead. The process maintains effective spinel compound formation while fundamentally changing the decomposition products to eliminate harmful emissions.
2Ease of manufacture
If metal nitrate precursors are used to prepare lithium manganese oxide spinel compounds, then the spinel compounds can be formed, but costly and dangerous exhaust gas treatment is required
Solution Approach 1:
The invention extracts and removes the nitrogen-containing component (nitrate group) from the precursor materials that causes the harmful NOx emissions. By selecting precursor materials without nitrogen (such as carbonates, hydroxides, or oxides), the source of the problematic exhaust gas is eliminated entirely. This extraction of the harmful element from the process simplifies the overall manufacturing system by removing the need for complex exhaust gas treatment equipment.
3Productivity
If conventional processes are used to prepare lithium manganese oxide spinel compounds, then the compounds can be produced, but high capacity and good cyclability are not achieved
Solution Approach 1:
The invention changes multiple parameters including precursor composition (using carbonates, hydroxides, or oxides instead of nitrates), particle size distribution (controlling D90 to be at least 2.0 μm), and calcination conditions. These parameter changes result in spinel compounds with improved crystal structure quality, higher capacity (at least 120 mAh/g), and excellent cyclability (at least 92% retention after 200 cycles), thereby simultaneously improving productivity and reliability.
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 process eliminates NOx gas generation, producing lithium manganese nickel spinel compounds with a high capacity of at least 120 mAh/g and 93% capacity retention after 200 cycles, while avoiding costly exhaust gas treatment.
Implementation Method 1
the Mn-containing precursor, Ni-containing precursor, Li-containing precursor and optional M-containing precursor are selected such that substantially no NOx gases are formed during the calcination in step (c)
Implementation Method 2
(b) milling the composition
Implementation Method 3
(c) calcining the product of step (b)
Data Source
AI summary
The present invention belongs to the field of battery materials, and relates to a process for preparing a particulate lithium manganese nickel spinel compound, and materials produced by the process. The process of the invention uses Mn-containing precursors, Ni-containing precursors, Li-containing precursors and optionally M-containing precursor which form substantially no NOx gases during calcination. The particulate lithium manganese nickel spinel compound product of the process may find use in a lithium ion battery.