Lithium iron phosphate/lithium metaaluminate compound anode material and preparation method thereof

A composite cathode material, lithium metaaluminate technology, applied in nanotechnology for materials and surface science, battery electrodes, electrical components, etc., can solve the problem of rate performance and cycle performance improvement, poor compatibility, lithium ion conductivity There is no improvement in the rate, and the effect of improving the cycle performance, high consistency, and improving the liquid absorption and liquid retention capacity is achieved.

Active Publication Date: 2018-11-27
JIANGSU LENENG BATTERY INC
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, lithium iron phosphate is mainly prepared by solid phase method, and its surface is coated with carbon and doped with metal elements to increase the gram capacity of the material. For example, the patent (CN102013489 A) discloses a metal titanium-doped carbon-coated lithium iron phosphate and Its preparation method, its preparation process is: lithium source, Fe 2 o 3 、TiO 2 and NH 4 h 2 PO 4 According to the molar ratio of lithium: iron: titanium: phosphorus = 1:1-x:x:1 ratio weighing for batching, where 0 < x ≤ 0.2; then add acetone, grind, dry and add saturated aqueous solution of citric acid to make The precursor of the rheological phase is then calcined in an inert atmosphere to prepare a high-capacity, high-tap density lithium iron phosphate material, but the carbon layer coated on the surface of the material does not improve the conductivity of lithium ions, which affects its rate performance and cycle performance. The improvement is small; at the same time, titanium dioxide is an inorganic compound, resulting in poor doping uniformity of the material and poor compatibility with the electrolyte

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  • Lithium iron phosphate/lithium metaaluminate compound anode material and preparation method thereof
  • Lithium iron phosphate/lithium metaaluminate compound anode material and preparation method thereof
  • Lithium iron phosphate/lithium metaaluminate compound anode material and preparation method thereof

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Embodiment 1

[0023] A preparation method of lithium iron phosphate / lithium metaaluminate composite material, comprising the following steps:

[0024] 1) Preparation of lithium iron phosphate precursor:

[0025] Take 7.4g (0.1mol) of lithium carbonate, 29.8 (0.2mol) of ammonium phosphate, add 500ml of water to dissolve, mix well; then weigh 5.8g (0.02mol) of theophylline, add 100ml of water to dissolve, and add 3.6g of (0.2mol) ferrous nitrate, mix well; then mix the above two solutions, and adjust the pH value of the mixed solution to 7 by carbon dioxide, stir and fully react at 95°C for 12h, and obtain lithium iron phosphate precursor A after filtration ;

[0026] 2) Preparation of porous lithium metaaluminate airgel:

[0027] Preparation of porous lithium metaaluminate airgel: 10 g of sodium metaaluminate solution was adjusted to pH 8 with 0.1 mol / L hydrochloric acid to form sol aluminum hydroxide sol. The aluminum hydroxide sol was put into an oven and dried at a temperature of 50° C...

Embodiment 2

[0031] 1) Preparation of lithium iron phosphate precursor:

[0032] Weigh 6.66g (0.09mol) lithium carbonate, 2.07g (0.018mol) ammonium dihydrogen phosphate, add 500ml water to dissolve, mix well; then weigh 4.83g (0.015mol) cyanidin, add 100ml water to dissolve, and Add 2.286g (0.018mol) ferrous chloride to the solution, mix well; then mix the above solution, adjust the pH value of the mixed solution to 6.5, stir and fully react at 90°C for 6h, and obtain lithium iron phosphate after filtration Precursor A;

[0033] 2) Preparation of porous lithium metaaluminate airgel:

[0034] Preparation of porous lithium metaaluminate airgel: 10 g of sodium metaaluminate solution was adjusted to pH 8 with 0.1 mol / L hydrochloric acid to form sol aluminum hydroxide sol. The aluminum hydroxide sol was dried in an oven at 50°C for 3 h to form an aluminum hydroxide gel. Then place it in 100ml, 0.1mol / l lithium carbonate solution to form a lithium metaaluminate gel, then put the gel into a hi...

Embodiment 3

[0038] 1) Preparation of lithium iron phosphate precursor:

[0039] Weigh 8.14g (0.11mol) of lithium carbonate, 2.90g (0.022mol) of diammonium hydrogen phosphate, add 500ml of water to dissolve, mix well; then weigh 12.2g (0.02mol) of rutin, add 100ml of water to dissolve, and add to the solution Add 1.58g (0.022mol) of ferrous oxide into the solution, mix well; then mix the above solutions, adjust the pH value of the mixed solution to 7.5, stir and fully react at 100°C for 6h, and obtain lithium iron phosphate precursor A after filtration ;

[0040] 2) Preparation of porous lithium metaaluminate airgel:

[0041] Preparation of porous lithium metaaluminate airgel: 10 g of sodium metaaluminate solution was adjusted to pH 8 with 0.1 mol / L hydrochloric acid to form sol aluminum hydroxide sol. The aluminum hydroxide sol was dried in an oven at 50°C for 3 hours to form an aluminum hydroxide gel. Then place it in 100ml, 1.0mol / l lithium carbonate solution to form a lithium metaal...

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Abstract

The invention belongs to the preparation field of an anode material for lithium ion batteries and specifically relates to a lithium iron phosphate / lithium metaaluminate compound anode material and a preparation method thereof. The compound material has a core-shell structure; an inner core is made from lithium iron phosphate; a shell is formed by coating with titanium oxide, porous lithium metaaluminate and carbon thereof. The preparation method thereof comprises the following steps: firstly, preparing a porous lithium metaaluminate gel according to a supercritical drying method; mixing the porous lithium metaaluminate gel with an organic titanium compound, thus obtaining an alkaline solution; coating the surface of a lithium metaaluminate precursor; spray-drying and carbonizing, thus obtaining the lithium iron phosphate / lithium metaaluminate compound material. According to the invention, the titanium oxide formed by carbonizing an organic titanium compound is doped into lithium iron phosphate so as to improve the specific capacity of the material and is doped into the porous lithium metaaluminate so as to improve the transmission rate of lithium ions in the charging and discharging process of the material, the liquid-absorbing liquid-holding capacity of the material and the cycling performance of the material.

Description

technical field [0001] The invention belongs to the field of lithium ion battery material preparation, in particular to a lithium iron phosphate / lithium metaaluminate composite positive electrode material and a preparation method thereof. Background technique [0002] As the Ministry of Finance announced the "Notice on the Financial Support Policy for the Promotion and Application of New Energy Vehicles from 2016 to 2020", the notice pointed out that the subsidy policy for the promotion and application of new energy vehicles will continue to be implemented in 2016-2020, requiring pure electric passenger vehicles The mass energy density of the power battery system is not less than 90Wh / kg, and subsidies higher than 120Wh / kg are given by 1.1 times. Lithium-ion batteries are required to have higher energy density or long cycle life to improve their lithium iron phosphate batteries. The efficiency of use (cruising range) and improve its service life. Lithium iron phosphate is u...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/36H01M4/485H01M4/58H01M10/0525B82Y30/00
CPCB82Y30/00H01M4/366H01M4/485H01M4/5825H01M10/0525Y02E60/10
Inventor 丁建民
Owner JIANGSU LENENG BATTERY INC
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