Disclosure of Invention
In order to solve the technical defects, the invention adopts the technical scheme that the preparation method of the novel ZrMn based hydride composite anode material of the lithium ion battery comprises the following steps:
s1, smelting: at room temperature, carrying out acid cleaning, impurity removal and drying on pure zirconium and pure manganese, and then smelting to obtain the ZrMn alloy;
s2, hydrogenation ball milling: the ZrMn alloy is crushed and then placed into a hydrogen filling tank, and hydrogen filling and ball milling are carried out for hydrogenation treatment to obtain ZrMn hydride;
s3, mechanical mixing: and grinding and mixing the ZrMn hydride and the carbon material in agate, and putting the mixture into a hydrogen charging tank for hydrogen charging and ball milling to obtain the carbon-coated ZrMn hydride composite material, wherein the carbon-coated ZrMn hydride composite material is the novel ZrMn-based hydride composite negative electrode material of the lithium ion battery.
Preferably, in step S1, the molar percentage of the pure zirconium metal and the pure manganese metal is 1: 1.5-2.1.
Preferably, in step S1, the melting of the ZrMn alloy is performed by high-frequency induction melting under the protection of argon, the power of the high-frequency induction melting is 15KW to 18KW, and the melting time is 80S to 100S.
Preferably, the hydrogen pressure of the hydrogenation treatment in the step S2 is 3MPa to 5MPa, and the hydrogen pressure of the hydrogenation treatment in the step S3 is 1MPa to 2 MPa.
Preferably, the carbon material is one of graphite, carbon nanotube and graphene.
Preferably, in the step S3, the mass percentage of the ZrMn hydride to the carbon material is 70% to 80% to 20% to 30%.
Preferably, in step S2, the mechanical ball milling process parameters are set as follows: the ball-material ratio is 60: 1, the ball milling rotation speed is 400rpm, and the ball milling time is 2 h-5 h.
Preferably, in step S3, the mechanical ball milling process parameters are set as follows: the ball-material ratio is 40: 1, the ball milling rotating speed is 300 rpm-400 rpm, and the ball milling time is 2 hours.
Preferably, the carbon-coated ZrMn hydride composite negative electrode material is prepared by the preparation method of the novel ZrMn hydride composite negative electrode material for the lithium ion battery, and the carbon-coated ZrMn hydride composite negative electrode material is the novel ZrMn hydride composite negative electrode material for the lithium ion battery.
Compared with the prior art, the invention has the beneficial effects that: the ZrMn based hydride composite material prepared by the invention can be used as a negative active material of a lithium ion battery. The material has excellent cycle performance and specific capacity, and has simple preparation process, low equipment requirement and short production period; the ZrMn-based hydride composite active material can be simply and feasibly prepared by the method, and has the advantages that the composite material realizes the strong coupling effect between the ZrMn-based hydride and the carbon material, the ZrMn-based hydride has higher specific discharge capacity, the carbon material improves the conductivity of the ZrMn-based hydride, and the ZrMn-based hydride composite active material has excellent electrochemical performance when being used as an electrode material of a lithium ion battery, so that the ZrMn-based hydride composite active material has wide application prospect in the fields of various new energy sources and new materials such as energy storage materials, advanced functional material preparation and the like.
Detailed Description
The above and further features and advantages of the present invention are described in more detail below with reference to the accompanying drawings.
The invention relates to a preparation method of a novel ZrMn-based hydride composite anode material of a lithium ion battery, which comprises the following steps:
s1, preparation of ZrMn alloy: washing pure zirconium and manganic acid at room temperature to remove impurities and drying, weighing the pure zirconium and manganese after acid washing according to a certain mole percentage, and smelting;
s2, preparation of ZrMn hydride: and (4) crushing the ZrMn alloy obtained in the step (S1), putting the crushed ZrMn alloy into a hydrogen filling tank, performing hydrogen filling ball milling, and performing hydrogenation treatment to obtain ZrMn hydride, wherein the mechanical ball milling process parameters are as follows: the ball-material ratio is 60: 1, the ball milling rotation speed is 400rpm, and the ball milling time is 2 h-5 h.
S3, preparation of ZrMn hydride composite material: weighing ZrMn hydride and carbon materials prepared in the step S2 according to a certain mass percentage, grinding and uniformly mixing the ZrMn hydride and the carbon materials in agate, then putting the uniformly mixed product into a hydrogen filling tank for hydrogen filling and ball milling treatment to obtain the carbon-coated ZrMn hydride composite material, wherein the mechanical ball milling process parameters are as follows: the ball-material ratio is 40: 1, the ball milling rotating speed is 300 rpm-400 rpm, and the ball milling time is 2 hours.
In step S1, the mol percent of Zr and Mn is 1: 1.5-2.1.
The smelting of the ZrMn alloy is high-frequency induction smelting under the protection of argon, wherein the power is controlled to be 15 KW-18 KW, and the smelting time is 80 s-100 s.
The hydrogen pressures in the hydrogenation treatment in step S2 and step S3 are 3MPa to 5MPa and 1MPa to 2MPa, respectively.
The carbon material is one of graphite, carbon nano tube and graphene.
The mass percentage of ZrMn hydride to carbon material is 70% -80% to 20% -30%.
The carbon-coated ZrMn-based hydride composite negative electrode material is prepared by the preparation method of the novel ZrMn-based hydride composite negative electrode material of the lithium ion battery.
After 500 cycles of charge and discharge under the current density of 500mA/g, the ZrMn-based hydride composite negative electrode material still keeps the specific discharge capacity at 450mAh/g, and the coulombic efficiency is up to 99%.
The ZrMn based hydride composite material prepared by the invention can be used as a negative active material of a lithium ion battery. The material has excellent cycle performance and specific capacity, simple preparation process, low equipment requirement and short production period. The test was carried out with a lithium metal sheet as the negative electrode, a polypropylene microporous membrane Celgard2400 as the separator, and a commercial electrolyte (LiPF)6As electrolyte, EC and DMC were solvents and volume ratio was 1: 1), assembled into CR2032 type button cell in a glove box.
The method can be used for simply and feasibly preparing the ZrMn-based hydride composite active material, and has the advantages that the composite material realizes the strong coupling effect between the ZrMn-based hydride and the carbon material, the ZrMn-based hydride has higher specific discharge capacity, the carbon material improves the conductivity of the ZrMn-based hydride, and the ZrMn-based hydride composite active material has excellent electrochemical performance when being used as an electrode material of a lithium ion battery, so that the ZrMn-based hydride composite active material has wide application prospect in the fields of various new energy sources and new materials such as energy storage materials, advanced functional material preparation and the like.
The following is illustrated by specific examples:
example one
The preparation method of the ZrMn-based hydride active material comprises the following steps:
s1, preparation of ZrMn alloy:
at room temperature, metal zirconium blocks and manganese sheets with the purity of 99% are washed for 3 minutes by 10% diluted hydrochloric acid, then washed and dried by deionized water, 20g of zirconium and manganese are respectively weighed according to the mol percentage of 1: 2, the zirconium and manganese are put into a high-frequency induction smelting furnace, argon is introduced for protection to carry out smelting, the power of the smelting furnace is regulated and controlled at 16KW, and the time is 80 s.
S2, preparation of ZrMn hydride:
the ZrMn alloy is crushed, 2g of ZrMn alloy powder is weighed and placed in a hydrogen filling tank, 3Mpa hydrogen is filled in the hydrogen filling tank for ball milling treatment, and ZrMn hydride is obtained, wherein the mechanical ball milling technological parameters are as follows: the ball-material ratio is 60: 1, the ball milling rotation speed is 400rpm, and the ball milling time is 2 h.
S3, preparation of ZrMn hydride composite material:
weighing 200mg of ZrMn hydride prepared in S2 and graphene according to the mass percent of 75: 25, grinding and uniformly mixing in agate, then putting the uniformly mixed product into a hydrogen charging tank, charging 2Mpa of hydrogen, and carrying out ball milling treatment to obtain the graphene-coated ZrMn hydride composite material, wherein the mechanical ball milling technological parameters are as follows: the ball-material ratio is 40: 1, the ball milling rotation speed is 400rpm, and the ball milling time is 2 h. An SEM image of the graphene-coated ZrMn hydride composite material is shown in fig. 2.
Phase XRD patterns of the ZrMn alloy, the ZrMn hydride and the ZrMn hydride composite material are shown in figure 1, and the product does not generate phase change and impurity substances. Wherein, the SEM image of the ZrMn hydride composite material is shown in fig. 2, and the ZrMn hydride is coated by graphene.
The graphene-coated ZrMn hydride composite material is used as an active electrode of a lithium ion battery, a metal lithium sheet is used as a negative electrode, a polypropylene microporous membrane Celgard2400 is used as a diaphragm, and a commercial electrolyte (LiPF)6As electrolyte, EC and DMC were solvents and volume ratio was 1: 1), assembled into CR2032 type button cell in a glove box.
As shown in FIG. 3, the cyclic voltammogram has a lower first-turn reduction peak, a weaker redox peak, good coincidence of the second and third curves, and less irreversible lithium ion loss at a sweep rate of 0.1 mV/s.
FIG. 4 is a charging and discharging curve diagram under the current density of 100mA/g and in the range of 0.01V to 3V, the first discharging specific capacity is up to 890mAh/g, the charging specific capacity is 620mAh/g, the first-turn coulombic efficiency is 70%, and the high discharging specific capacity is shown.
FIG. 5 shows the rate capability of ZrMn hydride composites at different current densities, with specific discharge capacities changing from 634.6mAh/g, 490mAh/g, 390.2mAh/g, 310.6mAh/g to 240.8mAh/g at current densities of 100mAh/g, 200mAh/g, 500mAh/g, 1000mAh/g to 2000 mAh/g. When the current density is recovered to 100mAh/g, the specific discharge capacity can be recovered to 606.2mAh/g, which indicates that the ZrMn hydride composite material has better reversibility.
Example two
The preparation method of the ZrMn based hydride composite active material comprises the following steps:
s1, preparation of ZrMn alloy:
at room temperature, metal zirconium blocks and manganese sheets with the purity of 99% are washed for 3 minutes by 10% diluted hydrochloric acid, then washed and dried by deionized water, 20g of zirconium and manganese are respectively weighed according to the mol percentage of 1: 1.5, the zirconium and manganese are put into a high-frequency induction smelting furnace, argon is introduced for protection to carry out smelting, the power of the smelting furnace is controlled at 18KW, and the time is 90 s.
S2, preparation of ZrMn hydride:
the ZrMn alloy is crushed, 2g ZrMn alloy powder is weighed and placed in a hydrogen filling tank, 4Mpa hydrogen is filled in the hydrogen filling tank for ball milling treatment to obtain ZrMn hydride, and the mechanical ball milling technological parameters are as follows: the ball-material ratio is 60: 1, the ball milling rotation speed is 400rpm, and the ball milling time is 2 h.
S3, preparation of ZrMn hydride composite material:
weighing 200mg of ZrMn hydride prepared in the step (2) and graphene according to the mass percentage of 80: 20, grinding and uniformly mixing in agate, then putting the uniformly mixed product into a hydrogen tank filled with 1Mpa, and performing hydrogen charging and ball milling treatment to obtain the graphene coated ZrMn hydride composite material, wherein the mechanical ball milling technological parameters are as follows: the ball-material ratio is 40: 1, the ball milling rotation speed is 400rpm, and the ball milling time is 2 h.
The graphene-coated ZrMn hydride composite material is used as an active electrode of a lithium ion battery, a metal lithium sheet is used as a negative electrode, a polypropylene microporous membrane Celgard2400 is used as a diaphragm, and a commercial electrolyte (LiPF)6As electrolyte, EC and DMC were solvents and volume ratio was 1: 1), assembled into CR2032 type button cell in a glove box.
Comparative example 1
S1, preparation of ZrMn alloy:
at room temperature, metal zirconium blocks and manganese sheets with the purity of 99% are washed for 3 minutes by 10% diluted hydrochloric acid, then washed and dried by deionized water, 20g of zirconium and manganese are respectively weighed according to the mol percentage of 1: 2, the zirconium and manganese are put into a high-frequency induction smelting furnace, argon is introduced for protection to carry out smelting, the power of the smelting furnace is regulated and controlled at 16KW, and the time is 80 s.
S2, preparation of ZrMn hydride:
the ZrMn alloy is crushed, 2g ZrMn alloy powder is weighed and placed in a hydrogen filling tank, 4Mpa hydrogen is filled in the hydrogen filling tank for ball milling treatment to obtain ZrMn hydride, and the mechanical ball milling technological parameters are as follows: the ball-material ratio is 60: 1, the ball milling rotation speed is 400rpm, and the ball milling time is 2 h.
ZrMn hydride material is used as lithium ion batteryA lithium metal sheet as a negative electrode, a U.S. Cellgard series separator, and a commercial electrolyte (LiPF)6As electrolyte, EC and DMC were solvents and volume ratio was 1: 1), assembled into CR2032 type button cell in a glove box.
By comparison between examples and comparative examples:
after 500 cycles of charge and discharge, the coulombic efficiency with the specific discharge capacity of 450mAh/g can reach 99%, the capacity decay is slow, the corresponding electrochemical stability is good (figure 6, the current density is 500mA/g), and compared with a ZrMn hydride active material, the capacity is improved by about 8 times.
The electrochemical impedance spectrum is shown in fig. 7, after the graphene is introduced, the impedance of the ZrMn hydride composite material is reduced, the conductivity is greatly improved, and the dynamic performance is improved.
The foregoing is merely a preferred embodiment of the invention, which is intended to be illustrative and not limiting. It will be understood by those skilled in the art that various changes, modifications and equivalents may be made therein without departing from the spirit and scope of the invention as defined in the appended claims.