Multi-component composite silica negative electrode material for lithium ion battery and preparation method thereof

A lithium-ion battery, multi-component composite technology, used in battery electrodes, electrical components, secondary batteries, etc.

Pending Publication Date: 2020-06-26

洛阳联创锂能科技有限公司

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AI-Extracted Technical Summary

Problems solved by technology

[0008] In order to overcome the deficiencies in the background technology, the present invention provides a multi-element composite silicon-oxygen negative electrode material for lithium ion batteries and a preparation method thereof. The present invention is based on the working principle of lithium ion second...

Abstract

The invention discloses a multi-component composite silica negative electrode material for a lithium ion battery and a preparation method thereof, and relates to the technical field of new material. The negative electrode material comprises six elements of Si, O, Li, C, La and Zr, the negative electrode material comprises a plurality of particle units, and each particle unit is of a core-shell structure. According to the working principle of a lithium ion secondary battery, the process of ineffectively consuming the lithium material by the negative electrode material after the battery is formed is advanced to be completed in advance in the material manufacturing process, so that the demand characteristic of high initial efficiency and long cycle life of the negative electrode material is achieved, and meanwhile, the amount of ineffectively consumed lithium during charging and discharging after the battery is manufactured is reduced, the reaction that the negative electrode material reacts with the liquid electrolyte to generate the solid electrolyte after the battery is prepared is weakened, and the amount of lithium consumed for forming a solid electrolyte membrane due to the reaction is reduced, and accordingly the purposes of improving the initial efficiency and prolonging the cycle life can be achieved.

Application Domain

Cell electrodesSecondary cells

Technology Topic

Composite materialCharge and discharge +5

Image

Examples

Experimental program(8)
Comparison scheme(2)
Effect test(1)

Example Embodiment

[0032] A preparation method of a multi-element composite silicon-oxygen anode material for lithium ion batteries, the preparation method specifically includes the following steps:

[0033] The first step is to first use silicon oxide powder with a carbon coating on the surface, mix it with the lithium source powder uniformly under the protection of a non-oxidizing atmosphere, and then heat the mixture to 350-750°C and heat it for 2-24 hours. After cooling to room temperature, a basic powder is obtained; the silicon oxide powder body with a carbon coating layer on the surface is a composite powder obtained by co-deposition of silicon oxide and carbon or a silicon oxide powder body is made and then passed through a carbon coating Coated powder; the carbon source for the coated carbon can be any one of sucrose, glucose, citric acid, pitch, furfuryl alcohol resin, phenolic resin, polyethylene, polystyrene, polypropylene, methane, propane, and acetylene Or a combination of two or more, the method is not limited to the gas phase method, the liquid phase method or the solid phase method; the particle size of the silica powder with a carbon coating layer on the surface is 1-20 microns, Preferably it is 1-10 microns, more preferably 3-8 microns; the lithium source powder is any one or a mixture of Li3N or LiH;

[0034] The second step is to combine the basic powder obtained in the previous step with the solid electrolyte LixLayZr2O12, 9 <16 or LixLayTi2O6, 3 <4 The materials are uniformly mixed and dried by a solid-phase or liquid-phase mixing method, and then heated to 100-600°C in a non-oxidizing atmosphere, and then subjected to heat preservation treatment for 1 to 6 hours and cooled to room temperature to obtain the target powder; Solid electrolyte LixLayZr2O12,9 <16 The material is a lithium ion conductor synthesized by the reaction of various raw materials containing lithium source, lanthanum source, zirconium source and oxygen source in the manufacturing process;

[0035] In the third step, the target powder obtained in the previous step is dispersed, impurity-removed and sieved to obtain the required multi-element composite silicon-oxygen anode material.

[0036] When the present invention is implemented, the lithium source is any one or a combination of two or more of lithium formate, lithium acetate, lithium propionate, lithium citrate, lithium carbonate, and lithium hydroxide.

[0037] Further, the lanthanum source is any one or a combination of two or more of lanthanum formate, lanthanum acetate, lanthanum propionate, lanthanum citrate, lanthanum carbonate, and lanthanum hydroxide.

[0038] Further, the zirconium source is selected from among zirconium acid, zirconium acetate, zirconium propionate, zirconium citrate, zirconium carbonate, zirconium hydroxide, methyl zirconate, ethyl zirconate, propyl zirconate, and butyl zirconate. Any one or a combination of two or more.

[0039] Further, the titanium source is any one or a combination of two or more of nano titanium dioxide, metatitanic acid, methyl titanate, ethyl titanate, propyl titanate, and butyl titanate.

[0040] Further, the oxygen source has been included in the lithium source, the source lanthanum, and the zirconium source.

[0041] Further, the solid phase mixing refers to any one or a combination of two or more of the fusion, mixing and milling, mechanical mixing, high-speed mechanical mixing, and ball milling.

[0042] Further, the liquid phase mixing refers to a method in which the raw materials are added to a liquid solvent for dispersion, mixing, and reaction. The liquid solvent refers to any one or a combination of two or more of the organic solvents ethanol, propanol, isopropanol, butanol, ethyl acetate, acetone, and toluene.

[0043] The invention has the characteristics of high charge and discharge efficiency and long cycle life, simple equipment and easy commercial production.

Example Embodiment

[0044] The specific embodiments of the present invention are as follows:

[0045] The invention adopts ICP-AES as the analysis means of material composition, and adopts the high-frequency induction carbon-sulfur analyzer as the analysis means of carbon content. Using the materials obtained in the examples and comparative examples, coin-type secondary batteries were produced to evaluate the usability of the materials.

[0046] First, prepare a silicon oxide powder with a carbon coating layer. Take commercially available silica powder with silicon-oxygen atom molar ratio of 1:1, particle size D50 of 6 microns, high-temperature petroleum pitch powder as carbon coating agent, and mechanically mix the two powders with a high-mixer in an appropriate ratio Then, put it into a vacuum heating furnace and heat it to 800 degrees Celsius for 2 hours, cool to room temperature, and then be broken up and sieved for use. Using this method, three basic powders with carbon content of 2.5%, 5.2%, and 7.6% were obtained.

Example Embodiment

[0047] Example 1

[0048] Take 100g of the basic powder with a carbon content of 2.5% and 10g of Li3N powder, mix them evenly in an argon protective box; then place them in an argon atmosphere for heat treatment at 500 degrees for 12h, and cool to room temperature naturally. Add 0.2g of lithium hydroxide, 0.7g of lanthanum hydroxide, and 0.9g of zirconium acetate to 100g of the above powders, and disperse them at a high speed to uniformly fuse them; then place them in an argon atmosphere for heat treatment at 600°C for 1h, and cool to room temperature naturally. Break up and screen to get the finished product.

PUM

Property	Measurement	Unit
Graininess	1.0 ~ 20.0	µm

Description & Claims & Application Information

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