Lithium titanate-titanium dioxide composite material formed in situ and preparation method thereof

A titanium dioxide, in-situ generation technology, applied in the direction of secondary batteries, electrochemical generators, electrical components, etc., can solve the problems of poor mixing uniformity of lithium titanate, affecting product performance, affecting applications, etc.

Active Publication Date: 2017-06-30
TIANJIN B&M SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, due to the presence of Ti-O bonds, the carbonate solvolysis in the electrolyte will cause flatulence, which affects its practical application.
[0003] The preparation method of the common lithium titanate-titanium dioxide composite material is: add lithium source and titanium source during the reaction, wherein the molar ratio of lithium element and titanium element is less than the stoichiometric ratio in lithium titanate, due to the existence of excess Ti, the formation Lithium titanate-titanium dioxide composite material is composed of lithium titanate and titanium dioxide mixed with each other. The defect of this method is that the mixing uniformity of lithium titanate is poor, and the existence of excess Ti is easy to generate other impurity compounds, which affects product performance.

Method used

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  • Lithium titanate-titanium dioxide composite material formed in situ and preparation method thereof
  • Lithium titanate-titanium dioxide composite material formed in situ and preparation method thereof
  • Lithium titanate-titanium dioxide composite material formed in situ and preparation method thereof

Examples

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Effect test

Embodiment 1

[0027] A method for preparing lithium titanate-titanium dioxide composite material in situ, comprising the steps of:

[0028] 1) adding titanium dioxide to 10 mol / l sodium hydroxide solution, in a hydrothermal reaction kettle, keeping the temperature at 180° C. for 48 hours to obtain material I;

[0029] Wherein the mol ratio of titanium dioxide and sodium hydroxide is 1:6;

[0030] 2) Add material I to 0.4mol / L [H + ] in the hydrochloric acid solution, wherein material I / acid solution=1g / 200ml, the reaction time is 48h, obtain ion exchange solution I;

[0031] 3) Put the ion exchange solution I into a high-speed centrifuge for washing and separation, collect the solids, and obtain the material II;

[0032] 4) Add the material II to a 1mol / l lithium hydroxide solution, mix well, add it to a hydrothermal reactor, and keep it warm at 150°C for 24 hours to obtain the ion replacement solution II;

[0033] 5) Wash and separate the ion exchange solution II in a high-speed centrif...

Embodiment 2

[0040] A method for preparing lithium titanate-titanium dioxide composite material in situ, comprising the steps of:

[0041] 1) adding titanium dioxide to 10 mol / l sodium hydroxide solution, in a hydrothermal reaction kettle, keeping the temperature at 210° C. for 18 hours to obtain material I;

[0042] Wherein the mol ratio of titanium dioxide and sodium hydroxide is 1:12;

[0043] 2) Add material I to 0.8mol / L [H + ] in the hydrochloric acid solution, wherein material I / acid solution=1g / 100ml, the reaction time is 12h, obtain ion replacement solution I;

[0044] 3) Put the ion exchange solution I into a high-speed centrifuge for washing and separation, collect the solids, and obtain the material II;

[0045] 4) Add the material II to a 2mol / l lithium hydroxide solution, mix it evenly, add it into a hydrothermal reactor, and keep it at 200°C for 12 hours to obtain the ion replacement solution II;

[0046] 5) Wash and separate the ion exchange solution II in a high-speed c...

Embodiment 3

[0053]1) adding titanium dioxide to 10mol / l sodium hydroxide solution, in a hydrothermal reaction kettle, keeping the temperature at 200°C for 36h to obtain material I;

[0054] Wherein the mol ratio of titanium dioxide and sodium hydroxide is 1:18;

[0055] 2) Add material I to 0.8mol / L [H + ] in the sulfuric acid solution, wherein material I / acid solution=1g / 150ml, the reaction time is 36h, obtain ion exchange solution I;

[0056] 3) Put the ion exchange solution I into a high-speed centrifuge for washing and separation, collect the solids, and obtain the material II;

[0057] 4) Add the material II to a 2mol / l lithium hydroxide solution, mix it evenly, add it to a hydrothermal reactor, and keep it at 180°C for 18 hours to obtain the ion replacement solution II;

[0058] 5) Wash and separate the ion exchange solution II in a high-speed centrifuge, collect the solids, and obtain the material III;

[0059] 6) Roasting the material III once at 800° C. for 12 hours to obtain ...

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Abstract

The invention discloses a lithium titanate-titanium dioxide composite material formed in situ and a preparation method thereof. The lithium titanate-titanium dioxide composite material is composed of three layers from interior to exterior, wherein the innermost layer is lithium titanate; the middle layer is titanium dioxide; and the outermost layer is carbon. The preparation method comprises the following steps: adding titanium dioxide into an aqueous solution of sodium hydroxide and carrying out a hydrothermal reaction; then adding a product of the previous step into an acid solution, carrying out ion substitution, then carrying out centrifugation to obtain a solid, adding the solid into a lithium hydroxide solution, then carrying out uniform mixing and adding the obtained mixture into a hydro-thermal reaction vessel for a reaction; and carrying out centrifugation again, subjecting a collected solid to primary roasting so as to obtain lithium titanate, adding an organic carbon source, and carrying out ball milling and secondary roasting successively so as to obtain the lithium titanate-titanium dioxide composite material formed in situ. The lithium titanate-titanium dioxide composite material has a core-shell structure, can inhibit bloating of a product and enables the product to have good safety performance and structural stability.

Description

technical field [0001] The invention relates to the field of negative electrode materials for lithium ion secondary batteries, in particular to an in-situ lithium titanate-titanium dioxide composite material and a preparation method thereof. Background technique [0002] A new lithium titanate material—Li 4 Ti 5 o 12 It has a large lithium ion solid-phase diffusion constant and submicron (or nanometer) particle size distribution, and has excellent fast charging performance (5 minutes charging capacity ≥ 80% full capacity) and fast discharging performance (maximum 50C A rate discharge); the lithium titanate negative electrode does not produce metal lithium during the charging and discharging process, and because the lithium titanate negative electrode has excellent fast charging and discharging performance, it can be used in conjunction with a new type of high-viscosity non-flammable electro-hydraulic, and the battery pack can withstand 240°C high-temperature shock, with e...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/36H01M4/48H01M4/485H01M4/62H01M10/0525
CPCH01M4/366H01M4/483H01M4/485H01M4/625H01M4/628H01M10/0525Y02E60/10
Inventor 宋英杰徐宁伏萍萍马倩倩吴孟涛
Owner TIANJIN B&M SCI & TECH
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