CN107516734B

CN107516734B - Preparation method of carbon-coated nickel-tin alloy nanospheres and application of nanospheres in lithium battery

Info

Publication number: CN107516734B
Application number: CN201710679962.8A
Authority: CN
Inventors: 洪振生; 何晓晴; 黄雅婧
Original assignee: Fujian Normal University
Current assignee: Fujian Normal University
Priority date: 2017-08-10
Filing date: 2017-08-10
Publication date: 2020-03-17
Anticipated expiration: 2037-08-10
Also published as: CN107516734A

Abstract

The invention belongs to the field of preparation of lithium ion battery electrode materials, and particularly relates to a preparation method of carbon-coated nickel-tin alloy nanospheres and application of the nanospheres in a lithium battery. The Ni coated with in-situ carbon is prepared by taking a nickel-based metal organic framework as a precursor, further mixing and grinding the precursor with stannous oxalate, and roasting the mixture in a tubular furnace₃Sn₂The composite nanometer material of the alloy nanometer sphere shows excellent rate performance and cycling stability. Carbon coated Ni₃Sn₂The first discharge capacity of the alloy nanosphere reaches 536mAh/g, the charge capacity reaches 397 mAh/g, and the first coulombic efficiency reaches 74%.

Description

Preparation method of carbon-coated nickel-tin alloy nanospheres and application of nanospheres in lithium battery

Technical Field

The invention belongs to the field of preparation of lithium ion battery electrode materials, and particularly relates to a preparation method of carbon-coated nickel-tin alloy nanospheres and application of the nanospheres in a lithium battery.

Background

Lithium ion batteries have been widely used because of their advantages of small size, light weight, high voltage, small self-discharge, good rate capability, environmental friendliness, high specific energy, and the like. The method is mainly applied to the fields of mobile electronic equipment, national defense industry, electric automobiles and the like. The electrode material is the core part of the lithium ion battery and is also a key factor for determining the performance of the lithium ion battery. At present, the theoretical specific capacity of the traditional graphite negative electrode material is 372 mAh/g, and the requirement of a new generation of high specific capacity lithium ion battery negative electrode material cannot be met. The alloy formed by bimetal has the advantages of higher theoretical capacity, lower cost and the like, and is expected to become an ideal lithium ion battery cathode material. However, the alloy has a very large volume change during the intercalation and deintercalation of lithium ions, which results in fast capacity fading and poor rate capability, and this disadvantage limits the practical application of the alloy in lithium ion batteries. Through the design and optimization of a synthesis process route, the transition metal oxide composite electrode material with a special structure and appearance is constructed, and the transition metal oxide composite electrode material has excellent electrochemical performance.

Disclosure of Invention

The invention aims to provide a preparation method of a carbon-coated nickel-tin alloy nanosphere and application of the carbon-coated nickel-tin alloy nanosphere in a lithium battery aiming at the defects of the prior art. In situ carbon coated Ni₃Sn₂The composite nanometer material of the alloy nanometer sphere shows excellent rate performance and cycling stability. Carbon coated Ni₃Sn₂The first discharge capacity of the alloy nanosphere reaches 536mAh/g, the charge capacity reaches 397 mAh/g, and the first coulombic efficiency reaches 74%.

In order to realize the technical scheme, the invention adopts the following technical scheme:

carbon-coated Ni₃Sn₂The preparation method of the alloy nanosphere comprises the following steps:

1) preparation of Ni-MOF precursor: 0.5-0.7g of Ni (NO)₃)₂And 0.4-0.6g polyvinylpyrrolidone in 35-40 mL methanol, dissolving 0.20-0.3g benzenetricarboxylic acid in 30-35mL methanol, slowly pouring the benzenetricarboxylic acid solution into Ni (NO) after completely dissolving₃)₂Fully mixing the methanol solution, putting the mixture into a high-pressure reaction kettle, putting the high-pressure reaction kettle into a 130-160 ℃ blast drying oven for reaction for 5-10 hours, washing the reaction product for 3-4 times by using methanol, and drying the reaction product to obtain a green Ni-MOF precursor;

2) carbon coated Ni₃Sn₂Preparing alloy nanospheres: weighing 80-120 mg of Ni-MOF precursorMixing and grinding the precursor and 80-160 mg stannous oxalate for 30-40 minutes, placing the ground sample in a tube furnace, roasting at 650 ℃ for 2-4 hours under the atmosphere of Ar to prepare in-situ carbon-coated Ni₃Sn₂Alloy nanospheres.

Carbon-coated Ni prepared by the preparation method₃Sn₂The application of the alloy nanospheres in the lithium ion battery cathode material comprises the following steps: coating carbon with Ni₃Sn₂The alloy nanospheres, the polytetrafluoroethylene and the acetylene black are mixed and ground according to the mass ratio of 75-85:5-10:10-15 to serve as a negative electrode material of the lithium battery.

The invention has the beneficial effects that:

the invention provides carbon-coated Ni for the first time₃Sn₂The preparation method of the alloy nanosphere is simple and convenient to operate, low in cost, high in purity, excellent in performance and capable of being synthesized in a large scale; preparing in-situ carbon-coated Ni₃Sn₂The composite nanometer material of the alloy nanometer sphere shows excellent rate performance and cycling stability. Carbon coated Ni₃Sn₂The first discharge capacity of the alloy nanosphere reaches 536mAh/g, the charge capacity reaches 397 mAh/g, and the first coulombic efficiency reaches 74%.

Drawings

FIG. 1 carbon-coated Ni₃Sn₂XRD pattern of alloy nanospheres;

FIG. 2 carbon-coated Ni₃Sn₂SEM image of alloy nanosphere;

FIG. 3 carbon-coated Ni₃Sn₂A charge-discharge curve graph of the alloy nanosphere;

FIG. 4 carbon-coated Ni₃Sn₂The multiplying power performance of the alloy nanospheres is shown.

Detailed Description

The present invention is further illustrated by the following examples, but the scope of the present invention is not limited to the following examples.

Example 1

Carbon coated Ni₃Sn₂The preparation method of the alloy nanosphere comprises the following steps:

1) preparation of Ni-MOF precursors: 0.6g of Ni (NO)₃)₂And 0.5g polyvinylpyrrolidone in 38mL of methanol, 0.25g benzenetricarboxylic acid in 32mL of methanol, after complete dissolution, slowly pouring the benzenetricarboxylic acid solution into Ni (NO)₃)₂Fully mixing the methanol solution, putting the mixture into a high-pressure reaction kettle, putting the high-pressure reaction kettle into a blowing drying oven at 145 ℃ for reaction for 7 hours, washing the reaction product for 3 times by using methanol, and drying to obtain a green Ni-MOF precursor;

2) in situ carbon coated Ni₃Sn₂Preparing alloy nanospheres: weighing 90 mg of Ni-MOF precursor and 120mg of stannous oxalate, mixing and grinding for 35 minutes; placing the ground sample in a tube furnace, roasting for 3 hours at 600 ℃ under the atmosphere of Ar to prepare in-situ carbon-coated Ni₃Sn₂Alloy nanospheres.

Assembling the lithium ion battery: coating Ni with carbon at a mass ratio₃Sn₂The alloy nanospheres are prepared by mixing and grinding polytetrafluoroethylene and acetylene black of 80:7:12, and uniformly coating the mixture on a substrate of 1.3 cm²The copper sheet is used as a negative electrode, the positive electrode is metal lithium, and the electrolyte is 1M LiPF₆EC + DEC + DMC (EC/DEC/DMC =1/1/1 v/v/v) solution. All assembly was performed in an argon filled glove box.

FIG. 1 is an XRD pattern of the alloy material, and the positions of diffraction peaks are compared with a standard card (JCPDS 65-1315), which shows that the prepared sample is Ni containing carbon₃Sn₂An alloy composite. From the SEM image in FIG. 2, spheres of about 1.5-2.0 um in diameter are seen, which are composed of carbon-bonded fine alloy particles (5-10 nm) by high power SEM image. In the invention, the particle size of the precursor can be adjusted by adjusting the content of nickel. As can be seen from the charge-discharge curve of FIG. 3, Ni is coated with carbon₃Sn₂The first discharge capacity of the alloy nanospheres reaches 536mAh/g, the charge capacity reaches 397 mAh/g, and the first coulombic efficiency reaches 74%; FIG. 4 shows carbon-coated Ni₃Sn₂The corresponding reversible specific capacities of the alloy nanospheres under the current densities of 100 mA/g, 200mA/g, 500 mA/g, 1000 m A/g and 2000 m A/g are 371mAh/g, 344mAh/g, 292mA/g, 248mAh/g and 1mAh/g respectively97mAh/g, which shows that the material has very excellent rate capability.

Example 2

1) preparation of Ni-MOF precursor: 0.5g of Ni (NO)₃)₂And 0.4g polyvinylpyrrolidone in 35mL of methanol, 0.20g benzenetricarboxylic acid in 30mL of methanol, after complete dissolution, slowly pouring the benzenetricarboxylic acid solution into Ni (NO)₃)₂Fully mixing the methanol solution, putting the mixture into a high-pressure reaction kettle, putting the high-pressure reaction kettle into a 130 ℃ blast drying oven for reaction for 5 hours, washing the reaction product for 3 times by using methanol, and drying to obtain a green Ni-MOF precursor;

2) in situ carbon coated Ni₃Sn₂Preparing alloy nanospheres: weighing 80mg of Ni-MOF precursor and 80mg of stannous oxalate, mixing and grinding for 30 minutes; placing the ground sample in a tube furnace, roasting for 4 hours at 500 ℃ under the atmosphere of Ar to prepare in-situ carbon-coated Ni₃Sn₂Alloy nanospheres.

Example 3

1) preparation of Ni-MOF precursor: 0.7g of Ni (NO)₃)₂And 0.6g polyvinylpyrrolidone in 40 mL of methanol, 0.3g benzenetricarboxylic acid in 35mL of methanol, after complete dissolution, slowly pouring the benzenetricarboxylic acid solution into Ni (NO)₃)₂Fully mixing the methanol solution, putting the mixture into a high-pressure reaction kettle, putting the high-pressure reaction kettle into a 160 ℃ blast drying oven for reaction for 10 hours, washing the reaction product for 4 times by using methanol, and drying to obtain a green Ni-MOF precursor;

2) in situ carbon coated Ni₃Sn₂Preparing alloy nanospheres: weighing 120mg of Ni-MOF precursor and 160mg of stannous oxalate, mixing and grinding for 40 minutes; placing the ground sample in a tubular furnace, roasting for 2 hours at 650 ℃ under the atmosphere of Ar to prepare in-situ carbon-coated Ni₃Sn₂Alloy nanospheres.

Claims

1. Carbon-coated Ni₃Sn₂The preparation method of the alloy nanosphere is characterized by comprising the following steps: the method comprises the following steps:

1) preparation of Ni-MOF precursor: 0.6g of Ni (NO)₃)₂And 0.5g polyvinylpyrrolidone in 38mL methanol, 0.25g benzenetricarboxylic acid in 32mL methanol, after complete dissolution, slowly pouring the benzenetricarboxylic acid solution into Ni (NO)₃)₂Fully mixing the methanol solution, putting the mixture into a high-pressure reaction kettle, putting the high-pressure reaction kettle into a blowing drying oven at 145 ℃ for reaction for 7 hours, washing the reaction product for 3 times by using methanol, and drying to obtain a green Ni-MOF precursor;

2) carbon coated Ni₃Sn₂Preparing alloy nanospheres: weighing 90 mg of Ni-MOF precursor and 120mg of stannous oxalate, mixing and grinding for 35 minutes, placing the ground sample in a tube furnace, roasting for 3 hours at 600 ℃ under Ar atmosphere to obtain in-situ carbon-coated Ni₃Sn₂Alloy nanospheres; coating the prepared carbon with Ni₃Sn₂The alloy nanospheres, the polytetrafluoroethylene and the acetylene black are mixed and ground according to the mass ratio of 75-85:5-10:10-15 to serve as a negative electrode material of the lithium battery.