Lithium Titanate Granulation for Battery Electrode Dispersion
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Solution Overview
Problem
Lithium titanate produced by existing methods faces challenges such as low reactivity due to solid phase diffusion reactions, leading to by-products and unreacted materials, and high firing temperatures result in volatilization loss and sintering issues, making it difficult to pulverize and disperse in electrodes for batteries.
Innovation Solution
A method involving thermal hydrolysis of titanyl sulfate to produce metatitanic acid, adjusting its pH for neutralization, and mixing with a lithium compound, followed by firing, to create lithium titanate granulated particles with improved pulverization and dispersion properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the firing temperature is raised to improve reactivity, then the reaction between lithium compound and titanium compound improves, but volatilization loss of lithium occurs and particle sintering increases making pulverization difficult
Solution Approach 1:
The patent applies preliminary action by pre-mixing lithium compound and titanium compound with a binder before firing to form granulated particles. This pre-arrangement ensures intimate contact between reactants, enabling complete reaction at lower temperatures without lithium volatilization loss.
Solution Approach 2:
The patent changes the physical state parameters of raw materials by converting them into granulated particles with controlled size distribution (D50: 5-20 μm) and porosity. This parameter change increases surface area and contact between reactants, allowing low-temperature reaction that prevents lithium volatilization while maintaining high reactivity.
2Reliability
If the firing temperature is raised to improve reactivity, then the reaction between lithium compound and titanium compound improves, but particle sintering increases making dispersion in electrodes difficult
Solution Approach 1:
The patent pre-forms granulated particles with controlled morphology and size distribution before firing. This preliminary structuring prevents sintering during reaction by maintaining particle integrity, ensuring easy pulverization and dispersion in electrode formulations.
Solution Approach 2:
The patent controls particle parameters (D50: 5-20 μm, porosity: 0.3-0.6 g/cm³) through granulation process parameters. These controlled parameters prevent excessive sintering during firing, maintaining particles that are easily pulverized and dispersed in electrodes while achieving complete reaction.
3Shape
If extensive grinding is performed to improve pulverization, then particle size decreases improving dispersion, but production time and energy consumption increase
Solution Approach 1:
The patent performs granulation with controlled size distribution (D50: 5-20 μm) before firing, creating particles that require minimal post-processing grinding. This preliminary size control reduces subsequent grinding time and energy consumption while achieving the desired fine particle size for good dispersion in electrodes.
4Loss of substance
If low firing temperature is used to prevent lithium loss, then volatilization loss is reduced, but reactivity between raw materials is insufficient producing by-products
Solution Approach 1:
The patent pre-mixes and granulates lithium compound and titanium compound with binder before firing. This preliminary intimate mixing ensures complete contact between reactants, enabling complete reaction even at low temperatures without forming by-products, while preventing lithium volatilization.
Solution Approach 2:
The patent changes the physical parameters of raw materials into granulated form with controlled porosity and surface area. This parameter change compensates for low firing temperature by increasing reactant contact efficiency, ensuring complete reaction without lithium loss.
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 enables the production of lithium titanate that can be easily pulverized and dispersed in electrodes, enhancing battery characteristics like low-temperature performance and rate capability, and reducing the need for extensive grinding.
Implementation Method 1
A step of thermal hydrolyzing titanyl sulfate or titanium sulfate to produce metatitanic acid
Data Source
AI summary
Provided is lithium titanate that is readily pulverized, and readily dispersed in a binding agent. The lithium titanate is characterized in that the value of a degree of pulverization Zd representing the ratio of the 50% cumulative diameter pre- and post-pulverization is 2 or greater. The lithium titanate is produced by the following steps (1)-(3). (1) a step in which titanyl sulfate or titanium sulfate is thermally hydrolyzed to produce metatitanic acid; (2) a step in which a slurry containing the metatitanic acid is prepared, and the slurry, subsequent to neutralization to bring the pH to 6.0-9.0, undergoes solid-liquid separation, to produce a metatitanic acid-containing titanium starting material having a BET specific surface area of 100-400 m2/g, and in which the sulfuric acid (SO4) content is 0.01-2.0 mass % with respect to the amount of metatitanic acid, on a TiO2-converted basis; and (3) a step in which the titanium starting material and a lithium compound are mixed and baked.