CN-121990553-A - Method for preparing hard carbon negative electrode of sodium ion battery with high cross-linked structure based on synergistic cross-linking of hydroxyl enriched lignin and oxidized asphalt

CN121990553ACN 121990553 ACN121990553 ACN 121990553ACN-121990553-A

Abstract

The invention provides a method for preparing a high-crosslinking-structure sodium ion battery hard carbon negative electrode based on synergistic crosslinking of hydroxyl enriched lignin and oxidized asphalt, which belongs to the technical field of sodium ion battery negative electrode material preparation, and realizes the preparation of a high-performance hard carbon negative electrode without solvent and additional additives by optimizing a lignin pretreatment process, an asphalt pre-oxidation process and improving an asphalt-lignin crosslinking mode.

Inventors

ZHAO QINGBO
MA JIANJUN
CHEN HENING
CAO ZUBIN
ZHAO HONGFU
XU WENBO
CHI LE
XU MAO
Cai tianfeng
LV XIAOJUN
SHI QUANBAO
DIAO JINGJING
HAN DONGYUN
YANG ZHANXU
YOU ZHUOLIN
WU JIANPO

Assignees

新疆天利石化股份有限公司
辽宁石油化工大学

Dates

Publication Date: 20260508
Application Date: 20251229

Claims (9)

1. A method for preparing a hard carbon anode of a sodium ion battery with a high cross-linked structure based on the synergistic cross-linking of hydroxyl enriched lignin and oxidized asphalt is characterized by comprising the following steps: (1) Lignin pretreatment: Mixing lignin with NaOH solution, stirring for reaction, filtering after the reaction is finished, adjusting the pH value to 6.0 after filter residues are removed, standing, washing with water to be neutral after standing is finished, drying, and grinding to obtain hydroxyl enriched modified lignin; (2) Pre-oxidizing asphalt: Crushing petroleum-based asphalt, placing the crushed petroleum-based asphalt in an oxidizing atmosphere, and heating to perform pre-oxidation treatment to obtain oxidized asphalt; (3) Crosslinking reaction: Grinding and mixing the obtained oxidized asphalt and hydroxyl enriched modified lignin, then carrying out pre-crosslinking reaction in an inert gas atmosphere, heating for continuous crosslinking, and obtaining a crosslinked product after crosslinking is finished; (4) Carbonization reaction: Crushing the crosslinked product, heating in an inert gas atmosphere to carry out carbonization reaction, and cooling after the reaction is finished to obtain the hard carbon cathode of the sodium ion battery with the high crosslinked structure.
2. The method of claim 1, wherein in the step (1), the solid-to-liquid ratio of lignin to NaOH solution is 1:8-12 (g/mL), the purity of lignin is not less than 92%, and the concentration of NaOH solution is 1-2 mol/L; The stirring reaction condition is that stirring is carried out for 2-6 hours at the constant temperature of 60-90 ℃.
3. The method according to claim 1, wherein in the step (1), a citric acid solution with a concentration of 0.5-1 mol/L is used to adjust the pH value to 5-6 and the mixture is left to stand and precipitate for 2-4 hours; the drying condition is that the vacuum drying is carried out for 8-12 hours at 80-100 ℃; The grinding conditions are that grinding is carried out to 100-200 meshes.
4. The method of claim 1, wherein in step (2), the petroleum-based asphalt comprises a petroleum-based asphalt having a softening point of 140-280 ℃; crushing petroleum-based asphalt to 80-100 meshes; the oxidizing atmosphere is oxygen-nitrogen mixed gas, wherein the volume fraction of the oxygen is 10-40%; The pre-oxidation treatment is carried out under the condition that the temperature rising rate is increased to 200-350 ℃ at 1-5 ℃ per minute, and the temperature is kept for 1-8 hours.
5. The method of claim 1, wherein in the step (3), the mass ratio of the oxidized asphalt to the hydroxyl-enriched modified lignin is 1:0.08-0.12; the inert gas is one of nitrogen and argon; The pre-crosslinking reaction condition is that the temperature is raised to 300-400 ℃ at 2-6 ℃ per minute for pre-crosslinking reaction for 1-4 hours; And the condition of continuous crosslinking is that the temperature is continuously increased to 450-600 ℃ at 2-6 ℃ per minute for crosslinking for 1-4 hours.
6. The method according to claim 1, wherein in the step (4), the crosslinked product is crushed to 80 to 100 mesh; The carbonization reaction is carried out under the conditions that the temperature rising rate is increased to 1000-1500 ℃ at 1-5 ℃ per minute, and the temperature is kept for 1-4 hours.
7. The hard carbon cathode of the sodium ion battery with the high cross-linked structure, which is prepared by the method according to any one of claims 1-6, is characterized in that the specific surface area of the hard carbon cathode is 5-100 m 2 /g, the interlayer spacing (d 002 ) of the hard carbon cathode material is 0.370-0.420 nm, and I D /I G is 1.0-2.0.
8. The use of the hard carbon negative electrode of the sodium ion battery with the high cross-linking structure in the preparation of the sodium ion battery.
9. A sodium ion battery comprising the hard carbon negative electrode of the sodium ion battery with a highly crosslinked structure of claim 7.

Description

Method for preparing hard carbon negative electrode of sodium ion battery with high cross-linked structure based on synergistic cross-linking of hydroxyl enriched lignin and oxidized asphalt Technical Field The invention belongs to the technical field of preparation of sodium ion battery anode materials, and particularly relates to a method for preparing a high-crosslinking-structure sodium ion battery hard carbon anode based on synergistic crosslinking of hydroxyl enriched lignin and oxidized asphalt. Background The demand of the sodium ion battery in the low-cost large-scale energy storage field is increasingly urgent, and the hard carbon is the anode material with optimal performance and strongest suitability in the current sodium ion battery, but the core bottleneck of the preparation process is still not broken through, which severely restricts the industrialization process. In the prior art, lignin and asphalt are used as raw materials for preparing hard carbon, but the lignin and asphalt have insufficient reaction cooperativity in the preparation process, and the matching degree of functional groups of the lignin and the asphalt is low, so that the precursor crosslinking driving force is deficient. Moreover, the traditional compound mode has obvious defects that the traditional compound mode is complicated in process steps and high in solvent recovery cost, or depends on volatile solvents such as ethanol and acetone for liquid phase mixing, and is difficult to adapt to industrial continuous production; or simple solid phase mixing is adopted, lignin and asphalt particles are easy to agglomerate and insufficient in contact, and finally the problem of uneven crosslinking is caused, so that a formed crosslinked network is loose and has many defects. The above problems lead to disorder of the pore structure of the hard carbon material (Kong Zhanbi to 30 percent larger), poor cycle stability (1000 times cycle capacity retention is often lower than 80 percent). Therefore, a lignin-asphalt synergistic crosslinking preparation method which has no solvent participation, simplified process and accurate matching of functional groups is developed, the problems of agglomeration and uneven crosslinking are solved by directionally strengthening the reactivity of the lignin-asphalt and the functional groups and optimizing a crosslinking mechanism, and a hard carbon material with excellent performance is further obtained, so that the method becomes a core requirement for promoting the industrial application of sodium ion batteries in the field of large-scale energy storage. Disclosure of Invention Aiming at some defects existing in the prior art, the invention provides a method for preparing a hard carbon negative electrode of a sodium ion battery with a high cross-linking structure based on the synergistic cross-linking of hydroxyl enriched lignin and oxidized asphalt; the preparation method of the high-performance hard carbon anode has the advantages that the preparation of the high-performance hard carbon anode can be realized without solvents or additional additives by optimizing the pretreatment process of lignin, the pitch pre-oxidation process and improving the pitch-lignin crosslinking mode, the biomass derivative and petroleum pitch composite carbon source is adopted, the low cost, the environmental friendliness and the availability of raw materials are achieved, the electrochemical performance of the sodium ion battery of the obtained hard carbon anode is excellent, the sodium ion battery is suitable for mass production of sodium ion batteries, and the practicability is good. In order to achieve the technical purpose, the invention adopts the following technical means: The invention firstly provides a method for preparing a hard carbon anode of a sodium ion battery with a high cross-linking structure based on the synergistic cross-linking of hydroxyl enriched lignin and oxidized asphalt, which comprises the following steps: (1) Lignin pretreatment: Mixing lignin with NaOH solution, stirring for reaction, filtering after the reaction is finished, adjusting the pH value to 6.0 after filter residues are removed, standing, washing with water to be neutral after standing is finished, drying, and grinding to obtain hydroxyl enriched modified lignin; (2) Pre-oxidizing asphalt: Crushing petroleum-based asphalt, placing the crushed petroleum-based asphalt in an oxidizing atmosphere, and heating to perform pre-oxidation treatment to obtain oxidized asphalt; (3) Crosslinking reaction: Grinding and mixing the obtained oxidized asphalt and hydroxyl enriched modified lignin, then carrying out pre-crosslinking reaction in an inert gas atmosphere, heating for continuous crosslinking, and obtaining a crosslinked product after crosslinking is finished; (4) Carbonization reaction: Crushing the crosslinked product, heating in an inert gas atmosphere to carry out carbonization reaction, and cooling after the reaction is finishe