CN-118270758-B - Negative electrode material of sodium ion battery and preparation method thereof

CN118270758BCN 118270758 BCN118270758 BCN 118270758BCN-118270758-B

Abstract

The application provides a negative electrode material of a sodium ion battery and a preparation method thereof. The preparation method of the sodium ion battery anode material comprises the steps of obtaining a coal-based raw material, performing defection operation on the coal-based raw material to enable the coal-based raw material to be subjected to oxidative crosslinking to obtain a pre-oxidized coal-based anode material, performing heat extraction treatment on the pre-oxidized coal-based anode material to remove organic impurities in the pre-oxidized coal-based anode material, and performing high-temperature doping operation on the pre-oxidized coal-based anode material after the heat extraction treatment to obtain the sodium ion battery anode material. The preparation method of the sodium ion battery anode material can effectively change the disorder degree of the microstructure, increase the interlayer spacing of the coal-based raw material, and further effectively improve the reversible specific capacity and the cycle performance.

Inventors

WANG JIANXING
FANG BO
ZHANG YUCHEN
Zhou Ruomeng
CHEN FAN

Assignees

广东一钠新能源科技有限公司

Dates

Publication Date: 20260508
Application Date: 20240223

Claims (7)

1. The preparation method of the negative electrode material of the sodium ion battery is characterized by comprising the following steps of: obtaining a coal-based raw material; performing defection operation on the coal-based raw material to enable the coal-based raw material to be subjected to oxidative crosslinking to obtain a pre-oxidized coal-based negative electrode material; Performing heat extraction treatment on the pre-oxidized coal-based anode material to remove organic impurities in the pre-oxidized coal-based anode material; Performing high-temperature doping operation on the pre-oxidized coal-based anode material after the heat extraction treatment, and heating to 1000-1500 ℃ in the high-temperature doping operation to obtain a sodium ion battery anode material; the defection operation is carried out on the coal-based raw material, specifically, the microwave heat treatment is carried out on the coal-based raw material under the oxygen condition; The method comprises the steps of carrying out microwave heat treatment on the coal-based raw material, namely placing the coal-based raw material in a microwave oven, carrying out microwave heat treatment on the coal-based raw material for 0.8-1.2 min under the condition that the power of microwaves is 180-220 w, carrying out microwave heat treatment on the coal-based raw material for 0.8-1.2 min under the condition that the power of microwaves is 350-420 w, carrying out microwave heat treatment on the coal-based raw material for 0.8-1.2 min under the condition that the power of microwaves is 580-650 w, carrying out microwave heat treatment on the coal-based raw material for 1.6-2.0 min under the condition that the power of microwaves is 1500-1200 w, and carrying out microwave heat treatment on the coal-based raw material for 4.8-5.5 min under the condition that the power of microwaves is 1500-460 w; performing heat extraction treatment on the pre-oxidized coal-based anode material by adopting an organic solvent; The organic solvent is N-methyl pyrrolidone.
2. The method for producing a negative electrode material for sodium ion battery according to claim 1, wherein the coal-based raw material comprises at least one of anthracite, bituminous coal, coking coal and lignite.
3. The method for preparing a negative electrode material of a sodium ion battery according to claim 1, wherein the pre-oxidized coal-based negative electrode material after the heat extraction treatment is subjected to high-temperature doping operation, comprising the following steps: Obtaining a doping source; Respectively placing the doping source and the pre-oxidized coal-based anode material at an air inlet and an air outlet, introducing inert gas into the air inlet, and enabling the inert gas to flow to the air outlet; and carrying out heat-up treatment on the doping source and the pre-oxidized coal-based anode material.
4. The method for preparing a negative electrode material for a sodium ion battery according to claim 3, wherein the doping source comprises at least one of elemental sulfur, elemental phosphorus, tin sulfide and antimony sulfide.
5. The method for preparing a negative electrode material of a sodium ion battery according to claim 3, wherein the flow rate of the inert gas is 100 mL-200 mL/min.
6. The method for preparing the negative electrode material of the sodium ion battery according to claim 3, wherein the doping source and the pre-oxidized coal-based negative electrode material are subjected to heating heat treatment, the temperature is raised to 1000-1500 ℃, the heating rate is 5-8 ℃ per minute, and then the temperature is kept for 5-8 hours.
7. A negative electrode material for sodium ion batteries, characterized by being prepared by the preparation method of the negative electrode material for sodium ion batteries as claimed in any one of claims 1 to 6.

Description

Negative electrode material of sodium ion battery and preparation method thereof Technical Field The invention relates to the technical field of electrochemical materials, in particular to a negative electrode material of a sodium ion battery and a preparation method thereof. Background Since sodium resources are abundant in reserves, sodium ions and lithium ions have similar oxidation-reduction potentials and similar physical and chemical properties, the sodium ions are regarded as the replacement of a low-cost energy storage device of a lithium ion battery, however, since the sodium ions have a larger radius, it is not easy to find a suitable electrode material for carrying the reversible repeated intercalation/deintercalation of sodium ions with a larger size, so that the exploration of a negative electrode material of the sodium ion battery with low cost, high reversible specific capacity and stable cycle performance has important practical significance. At present, the coal-based raw material is low in price and easy to process, and the like, so that the coal-based raw material is a production raw material which is more suitable for being used as a negative electrode material of a low-cost sodium ion battery, but the coal-based raw material is easy to graphitize in the carbonization process, so that the carbon layer arrangement of the prepared carbon negative electrode material tends to be ordered, the interlayer spacing is smaller, the carbon layer spacing is not enough for sodium storage meta-position, the reduction of the carbon layer spacing or interlayer translation easily occurs in the charge and discharge process, the negative electrode sodium storage capacity is reduced, and the capacity is rapidly attenuated along with the increase of the circulation number. For example, the China patent application No. 202310115655.2, the China patent application No. 202211040373.2 and the China patent application No. 202310490121.8 are all subjected to high-temperature doping treatment, specifically, pores of the coal-based raw material are increased, doping substances are doped in the pores of the coal-based raw material to improve conductivity and improve sodium storage space, but in practice, only the pores of the coal-based raw material are improved to limit the sodium storage space, or more carbon layers of the coal-based raw material tend to be orderly arranged, or more coal-based raw material tends to have reduced carbon layer spacing or interlayer translation. Disclosure of Invention The invention aims to overcome the defects in the prior art and provide the sodium ion battery anode material capable of effectively changing the disorder degree of a microstructure, increasing the interlayer spacing of coal-based raw materials and further effectively improving the reversible specific capacity and the cycle performance and the preparation method thereof. The aim of the invention is realized by the following technical scheme: The preparation method of the negative electrode material of the sodium ion battery comprises the following steps: obtaining a coal-based raw material; performing defection operation on the coal-based raw material to enable the coal-based raw material to be subjected to oxidative crosslinking to obtain a pre-oxidized coal-based negative electrode material; Performing heat extraction treatment on the pre-oxidized coal-based anode material to remove organic impurities in the pre-oxidized coal-based anode material; and carrying out high-temperature doping operation on the pre-oxidized coal-based anode material after the heat extraction treatment to obtain the anode material of the sodium ion battery. In one embodiment, the coal-based feedstock comprises at least one of anthracite, bituminous coal, coking coal, and lignite. In one embodiment, the coal-based feedstock is subjected to a defection operation, specifically, a microwave heat treatment of the coal-based feedstock under oxygen conditions. In one embodiment, the pre-oxidized coal-based negative electrode material is subjected to a thermal extraction treatment with an organic solvent. In one embodiment, the organic solvent is N-methylpyrrolidone. In one embodiment, the high-temperature doping operation is performed on the pre-oxidized coal-based anode material after the thermal extraction treatment, and the method comprises the following steps: Obtaining a doping source; Respectively placing the doping source and the pre-oxidized coal-based anode material at an air inlet and an air outlet, introducing inert gas into the air inlet, and enabling the inert gas to flow to the air outlet; and carrying out heat-up treatment on the doping source and the pre-oxidized coal-based anode material. In one embodiment, the doping source comprises at least one of elemental sulfur, elemental phosphorus, tin sulfide, and antimony sulfide. In one embodiment, the inert gas flow is 20 mL/min-60 mL/min. In one embodiment, the doping source and the pre-