阅读说明：本技术 一种具有电化学振荡效应LiCrTiO4的制备方法 (LiCrTiO with electrochemical oscillation effect4Preparation method of (1) ) 是由 李德 许智杰 陈永 于 2020-11-30 设计创作，主要内容包括：本发明提供一种具有电化学振荡效应LiCrTiO_4的制备方法,通过碳酸锂、纳米二氧化钛,三氧化二铬的配方调整,发现材料LiCrTiO_4在Li和Ti的比例在过量情况下具有电化学振荡效应,在特定的温度下煅烧,合成的LiCrTiO_4结晶度高无杂项。(The invention provides LiCrTiO with an electrochemical oscillation effect 4 The preparation method of (1) finds the material LiCrTiO by the formula adjustment of lithium carbonate, nano titanium dioxide and chromium sesquioxide 4 Has electrochemical oscillation effect when the ratio of Li to Ti is excessive, and the LiCrTiO synthesized by calcining at a specific temperature 4 High crystallinity and no impurity.)

1. LiCrTiO with electrochemical oscillation effect₄The preparation method is characterized by comprising the following steps: the method comprises the following steps:

s1, premixing: the molar ratio of Li, Ti and Cr is 1.0-1.10: 1.0-1.10: 1, weighing lithium carbonate, nano titanium dioxide and chromium sesquioxide, mixing and grinding for more than two hours to obtain powder;

s2, production and calcination: and sintering the powder in a muffle furnace in an air atmosphere, wherein the sintering condition is that the heating rate is 3-8 ℃/min, the temperature is 700-900 ℃, and the constant temperature time is 8-14 h to obtain the sample.

2. LiCrTiO with electrochemical oscillation effect according to claim 1₄The preparation method is characterized by comprising the following steps: in step S1, the molar ratio of the three elements Li, Ti, and Cr is 1.01: 1: 1.

3. LiCrTiO with electrochemical oscillation effect according to claim 1₄The preparation method is characterized by comprising the following steps: in step S1, the molar ratio of the three elements Li, Ti, and Cr is 1.1: 1: 1.

4. LiCrTiO with electrochemical oscillation effect according to claim 1₄A process for the preparation thereofCharacterized in that: in step S1, the molar ratio of the three elements Li, Ti, and Cr is 1: 1.01: 1.

5. LiCrTiO with electrochemical oscillation effect according to claim 1₄The preparation method is characterized by comprising the following steps: in step S1, the molar ratio of the three elements Li, Ti, and Cr is 1: 1.1: 1.

6. LiCrTiO with electrochemical oscillation effect according to claim 1₄The preparation method is characterized by comprising the following steps: in step S1, the sintering temperature is 800-900 ℃.

7. LiCrTiO with electrochemical oscillation effect according to claim 1₄The preparation method is characterized by comprising the following steps: in step S1, the sintering temperature is 850-900 ℃.

8. LiCrTiO with electrochemical oscillation effect according to claim 1₄The preparation method is characterized by comprising the following steps: in step S2, the sintering temperature is 850 ℃.

Technical Field

The invention relates to the field of electrochemistry, in particular to LiCrTiO with an electrochemical oscillation effect₄The preparation method of (1).

Background

At present, electrochemical oscillation effect of lithium titanate is only found, and LiCrTiO is a novel material₄The electrochemical oscillation effect is also realized, and the sintering at different temperatures also has the influence on the oscillation of the material, such as no oscillation effect exists at 700 ℃, and the electrochemical oscillation effect exists at 850 ℃ and 900 ℃. The ratio of Li to Ti is such that the oscillation effect is present only in excess and the electrochemical oscillation effect is absent in small amounts. Past LiCrTiO₄Only after extrusion molding, sintering is carried out, and an electrochemical oscillation effect does not exist, while the invention adopts powder sintering, and the sample is small particles with high dispersion degree and has the electrochemical oscillation effect.

Disclosure of Invention

Therefore, the invention provides LiCrTiO with electrochemical oscillation effect₄The above problems are solved by the preparation method of (1).

The technical scheme of the invention is realized as follows: LiCrTiO with electrochemical oscillation effect₄The preparation method comprises the following steps: the method comprises the following steps:

s1, premixing: weighing lithium carbonate and nano titanium dioxide, mixing the lithium carbonate and the nano titanium dioxide, and grinding for more than two hours, wherein the mass content of Li in the lithium carbonate is 90-110%, and the mass content of Ti in the nano titanium dioxide is 90-110%; grinding for more than two hours after mixing to ensure that the samples are fully and uniformly mixed; the XRD composition has a plurality of miscellaneous items and cannot generate electrochemical oscillation phenomenon after less than two hours;

s2, production and calcination: sintering the powder in a muffle furnace in an air atmosphere, wherein the sintering condition is that the heating rate is 3-8 ℃/min, the temperature is 700-900 ℃, the constant temperature time is 8-14 h to obtain a sample, and the sample cannot be formed due to too low temperature and cannot generate an electrochemical oscillation phenomenon;

further, in step S1, the molar ratio of the three elements Li, Ti, and Cr is 1.01: 1: 1.

further, in step S1, the molar ratio of the three elements Li, Ti, and Cr is 1.1: 1: 1.

further, in step S1, the molar ratio of the three elements Li, Ti, and Cr is 1: 1.01: 1.

further, in step S1, the molar ratio of the three elements Li, Ti, and Cr is 1: 1.1: 1.

further, in step S1, the sintering temperature is 800-900 ℃.

Further, in step S1, the sintering temperature is 850-900 ℃.

Further, in step S2, the sintering temperature is 850 ℃.

Compared with the prior art, the invention has the beneficial effects that:

(1) the invention prepares LiCrTiO with electrochemical oscillation effect₄The sample provides a new idea and sample selection for exploring the electrochemical oscillation effect compared with other similar products (such as lithium titanate with the electrochemical oscillation effect).

(2) The invention discovers LiCrTiO with stronger electrochemical oscillation effect₄The electrochemical oscillation effect of LiCrTiO4 is improved along with the increase of the sintering temperature.

(3) The invention discovers LiCrTiO₄Will disappear as the proportion of Ti or Li decreases and too high a content thereof will not affect the oscillatory effect.

(4) Past LiCrTiO₄Only after extrusion molding, sintering is carried out, and an electrochemical oscillation effect does not exist, while the invention adopts powder sintering, and the sample is small particles with high dispersion degree and has the electrochemical oscillation effect.

Drawings

FIG. 1 is LiCrTiO at 700 ℃ sintering for example 1₄Charge and discharge curve diagram

FIG. 2 is LiCrTiO at 800 ℃ sintering for example 1₄Charge and discharge curve diagram

FIG. 3 is LiCrTiO at 850 ℃ sintering for example 1₄Charge and discharge curve diagram

FIG. 4 is LiCrTiO at 900 ℃ sintering for example 1₄Charge and discharge curve diagram

FIG. 5 shows LiCrTiO synthesized by calcining LiCrTiO of example 1 at 700 deg.C, 800 deg.C, 850 deg.C, 900 deg.C, respectively₄XRD pattern of

FIG. 6 LiCrTiO with 10% Li excess for example 2₄Charge and discharge curve diagram

FIG. 7 is LiCrTiO example 3 with a small Li content of 10%₄Charge and discharge curve diagram

FIG. 8 is LiCrTiO with 10% Ti excess of example 4₄Charge and discharge curve diagram

FIG. 9 shows LiCrTiO with a small amount of 10% Ti in example 5₄Charge and discharge curve diagram

FIG. 10 shows LiCrTiO with 10% excess and 10% small amount of Li and Ti₄XRD pattern

Detailed Description

In order to better understand the technical content of the invention, specific examples are provided below to further illustrate the invention.

The experimental methods used in the examples of the present invention are all conventional methods unless otherwise specified.

The materials, reagents and the like used in the examples of the present invention can be obtained commercially without specific description.

The formulations of lithium carbonate, nano titanium dioxide, and chromium oxide of examples 1-5 are as follows:

sintering the powder weighed in the example 1 in a muffle furnace in an air atmosphere, wherein the sintering condition is that the heating rate is 5 ℃/min, the temperature is 700 ℃, 800 ℃, 850 ℃ and 900 ℃, and the constant temperature time is 10 hours to obtain a sample, and performing charge and discharge tests: test effects see fig. 1 to 5;

from the charge and discharge curves of the batteries of FIGS. 1 to 4, it can be seen that LiCrTiO increases with the increase of the sintering temperature₄The electrochemical oscillation effect is generated gradually in the charging process, and the amplitude is 8-10mV when the sintering temperature is 900 ℃.

As can be seen from FIG. 5, LiCrTiO was synthesized at a calcination temperature of 800 ℃ at 850 ℃ and 900 DEG C₄LiCrTiO synthesized at 700 ℃ and having high crystallinity without impurity₄There are miscellaneous items.

And (2) sintering the powder weighed in the examples 2 and 3 in a muffle furnace in an air atmosphere under the conditions that the heating rate is 5 ℃/min, the temperature is 850 ℃ and the constant temperature time is 10 hours to obtain a sample, and performing charge and discharge tests: test effects see fig. 6 to 7;

from two cycle graphs of electrochemical charge and discharge we can see that LiCrTiO is 10% excess Li₄The electrochemical oscillation effect is about 4-6mv during charging, and the small amount of Li is LiCrTiO accounting for 10%₄The charging process has no electrochemical oscillation effect.

And (2) sintering the powder weighed in the embodiments 4 and 5 in a muffle furnace in an air atmosphere, wherein the sintering condition is that the heating rate is 5 ℃/min, the temperature is respectively 850 ℃ and the constant temperature time is 10h to obtain a sample, and performing charge and discharge tests: test effects see fig. 8 to 9;

from two electrochemical chargesCycle plot of discharge we can see when Ti is 10% LiCrTiO in excess₄The electrochemical oscillation effect is about 3-4mv during charging, and the small amount of Ti is LiCrTiO accounting for 10 percent₄The charging process has no electrochemical oscillation effect.

From FIG. 10, it can be seen that LiCrTiO is synthesized with 10% excess of Li and Ti₄The crystallinity is high, no impurity is generated, and LiCrTiO is synthesized by small amount of Li and Ti of 10 percent₄There are miscellaneous items.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.