A kind of preparation method and application of large particle sodium chromite material

A technology of sodium chromite and large particles, applied in the direction of chromate/dichromate, structural parts, electrical components, etc., can solve the problems of many influencing factors and affecting the purity of products, so as to reduce side reactions and benefit The effect of de-intercalation and small specific surface area

Active Publication Date: 2021-02-05
CENT SOUTH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

There are many influencing factors in the preparation process of this process. Sodium and chromium elements are easy to segregate and form impurity phases when mixed, which in turn affects the purity of the product.

Method used

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  • A kind of preparation method and application of large particle sodium chromite material
  • A kind of preparation method and application of large particle sodium chromite material
  • A kind of preparation method and application of large particle sodium chromite material

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0047] Take a certain amount of sodium dichromate and put it into an alumina crucible, under Ar / H 2 (95%:5%v%) roasting under mixed atmosphere, the roasting temperature is 850 ℃, holding time is 10h. After the roasting is completed, cool to room temperature with the furnace, and the product obtained is NaCrO 2 Material.

[0048] The NaCrO that the present embodiment prepares 2 The particle size is 100 ~ 1000um, in the form of irregular block particles (such as figure 1 ), the layered structure is obvious (such as figure 2 ), XRD shows that the material is an O3-type layered oxide crystal structure ( image 3 ), without other impurity phases, the tap density is 2.55g / cm 3 .

[0049] After mixing the material with acetylene black and polyvinylidene fluoride (PVDF) at a ratio of 8:1:1, add the organic solvent N-methylpyrrolidone (NMP) as a dispersant, mix evenly and spread it on the aluminum foil. Put it into an oven at 120° C. and bake for 6 to 12 hours, and then punch i...

Embodiment 2

[0051] Take a certain amount of sodium dichromate and put it into an alumina crucible, 2 / H 2 (90%: 10% v%) roasting under mixed atmosphere, the roasting temperature is 900 ℃, holding time is 15h. After the roasting is completed, cool to room temperature with the furnace, and the product obtained is NaCrO 2 . The NaCrO that the present embodiment prepares 2 The particle size is 100-500um,

[0052] The battery was assembled according to the method of Example 1, and the charge and discharge test was carried out. The current density of the test was 10mA / g, and the voltage range was 2.3-3.6V. The charge and discharge curve of the first cycle is as follows: Figure 4 As shown, it can be seen that the curve has a long plateau at about 3.0V, the average discharge voltage is about 2.97V, and the discharge specific capacity is 123.0mAh / g.

Embodiment 3

[0054] Take a certain amount of sodium dichromate and put it into an alumina crucible, under Ar / H 2 (95%:5%v%) atmosphere roasting, the roasting temperature is 850 ℃, holding time is 12h. After the roasting is completed, cool to room temperature with the furnace, and the product obtained is NaCrO 2 . The NaCrO that the present embodiment prepares 2 The particle size is 50-200um. The battery is assembled according to the method of Example 1, and the charge-discharge test is carried out. The current density of the test is 10mA / g, and the voltage range is 2.3-3.6V. Figure 5 The cycle curve of the material shows that the discharge specific capacity in the first cycle is 123.2mAh / g, after 50 cycles, the specific capacity is 119.2mAh / g, and the capacity retention rate is as high as 96.8%. It can be seen that the material shows excellent cycle stability. Image 6 It is the cycle curve graph of different rates of material, where 1C=100mA / g, the test results show that: the first di...

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Abstract

The invention relates to a preparation method and application of a large particle sodium chromite material, belonging to the technical field of sodium ion batteries. In the method of the invention, sodium dichromate is put into a crucible, and roasted under a reducing atmosphere, the roasting temperature is controlled at 800-900 DEG C, and the holding time is 3-24 hours. After the roasting is completed, it is cooled with the furnace, and the product obtained is NaCrO 2 Material. The large particle NaCrO prepared by the method of the present invention 2 The particle size is 10-1000 μm, with excellent electrochemical performance and high tap density; the preparation process is simple, the raw material is cheap, the product is single, low consumption and environmental protection, and it is convenient to realize large-scale production. The prepared sodium chromite The material is used as a positive electrode material in a sodium-ion battery, and the resulting sodium-ion battery has high specific capacity, good rate performance and excellent cycle stability.

Description

technical field [0001] The invention belongs to the technical field of sodium ion batteries, and in particular relates to a preparation method and application of a large particle sodium chromite material. Background technique [0002] Among many energy storage technologies, lithium-ion batteries are favored for their high capacity, high energy density, and long cycle life. However, the reserves of lithium resources in the earth's crust are limited, and the large-scale application of lithium-ion batteries to electric vehicles and grid energy storage will make the lithium resources on the earth appear in short supply. Sodium, which is in the same main group as lithium, is one of the most abundant elements in the earth's crust, with a content as high as 2.3%. The price of sodium-containing minerals is much lower than that of lithium-containing mineral raw materials, so low-cost sodium-ion batteries are applied to large-scale Energy storage will be a better choice. [0003] At...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01G37/14H01M4/58H01M10/054
CPCC01G37/14C01P2002/72C01P2004/03C01P2004/62H01M4/5825H01M10/054Y02E60/10
Inventor 杜柯胡国荣彭忠东曹雁冰王勇李唯亓先跃
Owner CENT SOUTH UNIV
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