Spherical Precursor Synthesis for Li-Ion Battery Cathodes
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Solution Overview
Problem
Existing processes for producing precursors for lithium-ion battery electrodes, such as lithium-containing nickel-cobalt-manganese oxides, face challenges in cycle stability, high-current capability, and energy density, with issues related to waste production, solubility of salts, and high costs of lithium carbonate.
Innovation Solution
A process involving the precipitation of a material with the formula M(CO3)bOc(OH)dAmBe(SO4)fXg(PO4)h from aqueous solutions of transition metal salts and alkali metal carbonates, with controlled pH and molar ratios, to produce spherical particles that can be thermally treated into efficient electrode materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If oxide- and hydroxide-free spherical carbonates are produced by mixing transition metal salt solutions with alkali metal carbonate and alkali metal chloride solutions, then particle morphology and surface area are improved, but waste production increases due to the additional alkali metal salt
Solution Approach 1:
The invention extracts and eliminates the harmful component (alkali metal chloride waste) from the process by replacing the three-solution mixing method with a two-solution method that uses only alkali metal carbonate solution, thereby achieving spherical particles without generating harmful waste
Solution Approach 2:
The invention changes the chemical composition parameters of the precipitating solution by using alkali metal carbonate solution with controlled pH (8.0-9.0) and carbonate ion to metal molar ratio (0.7-1.3), which enables spherical particle formation without requiring additional alkali metal chloride
2Shape
If sodium bicarbonate is used for precipitation, then spherical particles can be formed, but large volumes of solution must be processed due to moderate solubility
Solution Approach 1:
The invention changes the carbonate source from sodium bicarbonate to alkali metal carbonate (such as sodium carbonate or potassium carbonate), which has higher solubility and allows precipitation with smaller solution volumes while maintaining spherical particle morphology through controlled pH and molar ratio parameters
3Reliability
If lithium carbonate is used to produce carbonate particles, then high-performance precursors can be obtained, but costs increase and lithium carbonate must be recovered
Solution Approach 1:
The invention replaces expensive lithium carbonate with cheaper alkali metal carbonates (sodium carbonate or potassium carbonate) as the precipitating agent. The alkali metal carbonate is consumed in the reaction and its cation ends up in the mother liquor, eliminating the need for expensive lithium carbonate recovery processes while maintaining precursor quality
Solution Approach 2:
The invention uses alkali metal carbonate as an intermediary substance that facilitates the precipitation of spherical carbonate particles without requiring lithium carbonate. The alkali metal cation serves as a temporary carrier that can be easily separated in the mother liquor, enabling cost-effective production of high-quality precursors
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 process enhances the production of precursors for lithium-ion batteries, improving cycle stability and energy density while reducing waste and costs, and allowing for efficient processing into high-performance electrodes.
Implementation Method 1
a material precipitates from aqueous solution at a pH in the range from 8.0 to 9.0 having the formula (I) M(CO 3 ) b O c (OH) d A m B e (SO 4 ) f are, to 0.50, in the range from zero to 0.1, in the range from zero to 0.05, in the range from zero to 0.05, in the range from zero to 0.10, in the range from 0.002 to 0.1 by combining aqueous solution of transition metal salt(s) in one or more steps with aqueous solution of one or more alkali metal carbonate(s)
Data Source
AI summary
Preparing precursors for transition metal mixed oxides, comprises: (a1) precipitating a material comprising metal oxide compounds (I) from aqueous solution at a pH value of 8-9, where the total concentration of the transition metals in the mother liquor is 50-2000 ppm; and (b1) separating the precipitated material from the mother liquor, where the particles of the materials have a spherical shape. Preparing precursors for transition metal mixed oxides, comprises: (a1) precipitating a material comprising metal oxide compounds of formula (M(CO 3) bO c(OH) dA1 mB1 e(SO 4) fX g(PO 4) h) (I) from aqueous solution at a pH value of 8-9, where the total concentration of the transition metals in the mother liquor is 50-2000 ppm; and (b1) separating the precipitated material from the mother liquor, where the particles of the materials have a spherical shape. M : one or more transition metals; A1 : Na or K; B1 : one or more metals of 1-3 groups of the periodic system, where Na and K are excluded; X : halide, nitrate or carboxylate; b : 0.75-0.98; c, d : 0-0.50, where c+d is 0.02-0.50; f, g : 0-0.05; e : 0-0.1; h : 0-0.10; and m : 0.002-0.1. Independent claims are included for: (1) the material comprising metal compounds (I); (2) preparing transition metal mixed oxides comprising thermal treatment of a mixture of the material comprising (I) and at least one lithium compound at 600-1000[deg] C; (3) transition metal mixed oxides obtained by the process; (4) electrode formulation obtained by mixing the transition metal mixed oxides with carbon in an electrically conductive form and optionally with at least one polymeric binder; and (5) electrochemical cell prepared using at least one electrode material comprising the transition metal mixed oxides or the electrode formulation.