CN1995490A

CN1995490A - Process for preparing lithium titanate crystal whisker

Info

Publication number: CN1995490A
Application number: CNA2006100224775A
Authority: CN
Inventors: 邓昭平; 夏新蕊; 王鹏威; 陈健利
Original assignee: Chengdu Univeristy of Technology
Current assignee: Sichuan State Lithium Materials Co., Ltd.
Priority date: 2006-12-12
Filing date: 2006-12-12
Publication date: 2007-07-11
Anticipated expiration: 2026-12-12
Also published as: CN100491602C

Abstract

The invention discloses a making method of spinel structured Li4Ti5O12 whisker material, which comprises the following steps: adding metatitanate in the sodium hydroxide solution; boiling and stirring 5h; washing the material through deionized water until the content of Na+ and SO42- is not more than 0.003%; removing Na+ and SO42- ion; drying metatitanate without Na+ and SO42- ion; making the free water content not more than 10%; balling 2h; testing TiO2 content through weight method; weighing dried metatitanate and lithium carbonate according to molar rate in the Li4Ti5O12 chemical formula; adding deionized water to mill 4-5h; filtering; placing material in the box stove; heating to 980-1050 deg. c with heating velocity at 10deg. c/min; insulating 4. 5-10h; cooling naturally; obtaining the product.

Description

The preparation method of lithium titanate crystal whisker

Technical field

The invention belongs to the preparation field of ceramic, particularly a kind of have a spinel structure lithium titanate Li ₄Ti ₅O ₁₂The Preparation of Whiskers method.

Background technology

That the positive electrode material of lithium ion battery generally adopts is LiCoO ₂, LiNiO ₂Or LiMn ₂O ₄, and that negative material main employing at present is embedding lithium carbon intercalation compound LixC ₆Material has good chargeable performance between embedding lithium carbon-coating, and volume change was little when lithium embedded, and is that a kind of good negative material is also used in industry already, but the lower (LixC of specific storage ₆Be 372mAh/g), and the separating to know from experience and cause capacity attenuation of carbon material, new negative material, Li developed for addressing these problems people ₄Ti ₅O ₁₂A kind of exactly good cycle, have good charge and discharge platform, theoretical specific capacity big (actual specific capacity can reach 165mAh/g), with electrolytic solution reaction with novel negative material zero strain.But, the Li of present prepared ₄Ti ₅O ₁₂Negative material still exists poorly conductive and high rate during charging-discharging is poor, density is low and shortcoming such as difficult formation high-voltage battery, can only use in limited scope up to now.At preparation lithium titanate (Li ₄Ti ₅O ₁₂) in the process of negative material, we find that a kind of preparation has the lithium titanate Li of spinel structure ₄Ti ₅O ₁₂The method of crystal whisker materials, so the present invention attempts to provide a kind of novel Li at this ₄Ti ₅O ₁₂The preparation method of base mateiral wishes that simultaneously this base mateiral and preparation method thereof has using value at other field (comprising negative material), at the retrieval domestic and foreign literature, does not find about lithium titanate (Li ₄Ti ₅O ₁₂) the research report of whisker.

Summary of the invention

The purpose of this invention is to provide a kind of spinel structure lithium titanate Li that has ₄Ti ₅O ₁₂The Preparation of Whiskers method, promptly metatitanic acid and the Quilonum Retard with cheapness is main raw material, with the Na in the deionized water eccysis metatitanic acid ⁺And SO ₄ ^2-Deng harmful ion, press Li ₄Ti ₅O ₁₂Molar ratio in the chemical formula, take by weighing metatitanic acid and Quilonum Retard after the oven dry, after the process ball milling is also crossed and is filtered to remove large quantity of moisture, place cabinet-type electric furnace, be warmed up to 980 ℃-1050 ℃ calcining scope and constant temperature 4.5～10 hours with 10 ℃/minute temperature rise rates from room temperature, behind the naturally cooling, promptly obtain a kind of spinel structure lithium titanate Li that has ₄Ti ₅O ₁₂Crystal whisker materials.

Preparation method of the present invention carries out according to the following steps:

(1) in metatitanic acid, add sodium hydroxide solution, be heated to the boiling and stirred 5 hours, with 2.5 times of volume of material deionized water wash to Na ⁺And SO ₄ ^2-Content≤0.003% (quality percentage composition), remove Na ⁺And SO ₄ ²Harmful ion.

(2) will remove Na ⁺And SO ₄ ²The metatitanic acid oven dry of harmful ion makes free water moisture≤10% wherein, and is mixed through 2 hours ball millings, adopts gravimetric determination TiO ₂Content.

(3) press Li ₄Ti ₅O ₁₂Molar ratio in the chemical formula, i.e. TiO in the metatitanic acid ₂Nt wt net weight: Quilonum Retard equals 100: 37, takes by weighing metatitanic acid and Quilonum Retard after the oven dry, and adds about 1～2.5 times of volume of material deionized water, about 4～5 hours of ball milling.

(4) after being removed large quantity of moisture, above-mentioned material filtering places cabinet-type electric furnace again, be warmed up to 980 ℃-1050 ℃ calcining scope and constant temperature 4.5～10 hours with 10 ℃/minute temperature rise rates from room temperature, behind the naturally cooling, promptly obtain having spinel structure lithium titanate Li ₄Ti ₅O ₁₂Crystal whisker materials.The main chemical reactions equation is as follows:

2Li ₂CO ₃+5TiO(OH) ₂＝Li ₄Ti ₅O ₁₂+2CO ₂+5H ₂O (1)

The purpose of above-mentioned steps (1) is to remove Na ⁺And SO ₄ ^2-Deng harmful ion.

The main purpose of above-mentioned steps (2) is to guarantee TiO ₂Accurately weighing.

Above-mentioned steps (3) and (4) are to set up on the basis of experiment.

Description of drawings

Fig. 1 is that as seen from the figure, sample is the Li of spinel crystal formation by the XRD diffractogram of back with the embodiment 1 acquisition sample of narration ₄Ti ₅O ₁₂

Fig. 2 is by the scanning electronic microscope SEM photo of back with the embodiment 1 acquisition sample of narration, by photo as can be known, the mean diameter of whisker≤0.5 μ m, the mean length of whisker is about 7 μ m.

Embodiment

Embodiment 1: have a spinel structure lithium titanate Li in the present embodiment ₄Ti ₅O ₁₂The preparation method of crystal whisker materials carries out according to the following steps:

In metatitanic acid, add sodium hydroxide solution, be heated to the boiling and stirred 5 hours, with 2.5 times of volume of material deionized water wash to Na ⁺And SO ₄ ^2-Content≤0.003% (quality percentage composition), remove Na ⁺And SO ₄ ²Harmful ion; To remove Na ⁺And SO ₄ ^2-The metatitanic acid oven dry makes free water moisture≤10% wherein, and is mixed through 2 hours ball millings, adopts gravimetric determination TiO ₂Content, stand-by; The metatitanic acid that has taken by weighing oven dry and measure content also makes wherein pure TiO ₂Be 100 grams, take by weighing Quilonum Retard 37 grams, and add about 1 times of volume of material deionized water, about 4 hours of ball milling; Cross and filter to remove large quantity of moisture; Place cabinet-type electric furnace again, be warmed up to 980 ℃ calcining and constant temperature 4.5 hours from room temperature, behind the naturally cooling, promptly obtain having spinel structure lithium titanate Li with 10 ℃/minute temperature rise rates ₄Ti ₅O ₁₂Crystal whisker materials, Measurement results is described in front.

Embodiment 2: have a spinel structure lithium titanate Li in the present embodiment ₄Ti ₅O ₁₂The preparation method of crystal whisker materials carries out according to the following steps:

Take by weighing in embodiment 1 handle and measure content metatitanic acid and make wherein pure TiO ₂Be 100 grams, take by weighing Quilonum Retard 37 grams, and add about 1.5 times of volume of material deionized waters, about 4.5 hours of ball milling; Cross and filter to remove large quantity of moisture; Place cabinet-type electric furnace again, be warmed up to 1000 ℃ calcining and constant temperature 5 hours from room temperature, behind the naturally cooling, promptly obtain containing the spinel type lithium titanate Li of part whisker with 10 ℃/minute temperature rise rates ₄Ti ₅O ₁₂The process test analysis: the mean diameter of whisker≤0.5 μ m, the mean length of whisker is about 7 μ m.

Embodiment 3: have a spinel structure lithium titanate Li in the present embodiment ₄Ti ₅O ₁₂The preparation method of crystal whisker materials carries out according to the following steps:

Take by weighing in embodiment 1 handle and measure content metatitanic acid and make wherein pure TiO ₂Be 100 grams, take by weighing Quilonum Retard 37 grams, and add about 2.5 times of volume of material deionized waters, about 5 hours of ball milling; Cross and filter to remove large quantity of moisture; Place cabinet-type electric furnace again, be warmed up to 1050 ℃ calcining and constant temperature 10 hours from room temperature, behind the naturally cooling, promptly obtain containing the spinel type lithium titanate Li of part whisker with 10 ℃/minute temperature rise rates ₄Ti ₅O ₁₂The process test analysis: the mean diameter of whisker≤0.5 μ m, the mean length of whisker is about 7 μ m.

Embodiment 4: have a spinel structure lithium titanate Li in the present embodiment ₄Ti ₅O ₁₂The preparation method of crystal whisker materials carries out according to the following steps:

Take by weighing in embodiment 1 handle and measure content metatitanic acid and make wherein pure TiO ₂Be 100 grams, take by weighing Quilonum Retard 37 grams, and add about 2.3 times of volume of material deionized waters, about 4.7 hours of ball milling; Cross and filter to remove large quantity of moisture; Place cabinet-type electric furnace again, be warmed up to 1020 ℃ calcining and constant temperature 8 hours from room temperature, behind the naturally cooling, promptly obtain containing the spinel type lithium titanate Li of part whisker with 10 ℃/minute temperature rise rates ₄Ti ₅O ₁₂The process test analysis: the mean diameter of whisker≤0.5 μ m, the mean length of whisker is about 7 μ m.

Claims

1, a kind of preparation method's method of lithium titanate crystal whisker is characterized in that, is main raw material with the metatitanic acid and the Quilonum Retard of cheapness, with the Na in the deionized water eccysis metatitanic acid ⁺And SO ₄ ^2-Harmful ion is pressed Li ₄Ti ₅O ₁₂Molar ratio in the chemical formula, take by weighing metatitanic acid and Quilonum Retard after the oven dry, after the process ball milling is also crossed and is filtered to remove large quantity of moisture, place cabinet-type electric furnace, be warmed up to 980 ℃-1050 ℃ calcining scope and constant temperature 4.5～10 hours, behind the naturally cooling, promptly obtain a kind of lithium titanate Li with spinel structure ₄Ti ₅O ₁₂Whisker;

2, preparation lithium titanate Li as claimed in claim 1 ₄Ti ₅O ₁₂The method of whisker is characterized in that, adds sodium hydroxide solution in metatitanic acid, be heated to the boiling and stirred 5 hours, with 2.5 times of volume of material deionized water wash to Na ⁺And SO ₄ ^2-Content≤0.003% (quality percentage composition), remove Na ⁺And SO ₄ ²Harmful ion;

3, preparation lithium titanate Li as claimed in claim 1 ₄Ti ₅O ₁₂The method of whisker is characterized in that, will remove Na ⁺And SO ₄ ²The metatitanic acid oven dry of harmful ion makes free water moisture≤10% wherein, and is mixed through 2 hours ball millings, adopts gravimetric determination TiO ₂Content;

4, preparation lithium titanate Li as claimed in claim 1 ₄Ti ₅O ₁₂The method of whisker is characterized in that, places cabinet-type electric furnace again after above-mentioned material filtering is removed large quantity of moisture, is warmed up to 980 ℃-1050 ℃ calcining scope and constant temperature 4.5～10 hours with 10 ℃/minute temperature rise rates from room temperature.