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CN-121974324-A - High specific capacity hard carbon material and preparation method and application thereof

CN121974324ACN 121974324 ACN121974324 ACN 121974324ACN-121974324-A

Abstract

The invention provides a high specific capacity hard carbon material, a preparation method and application thereof. The high specific capacity hard carbon material is prepared from raw materials including phenolic compounds, aldehyde compounds, catalysts and curing agents, and the preparation method comprises the following steps of (1) uniformly mixing the phenolic compounds, the aldehyde compounds and the catalysts in water to obtain a low molecular weight resin solution through reaction, (2) adding amine curing agents into the low molecular weight resin solution obtained in the step (1) to uniformly mix, carrying out hydrothermal reaction to obtain a high molecular weight crosslinked resin, and (3) carrying out low-temperature calcination on the high molecular weight crosslinked resin obtained in the step (2) in an oxygen-containing gas atmosphere, then carrying out high-temperature calcination in a protective gas atmosphere, and cooling to room temperature to obtain the high specific capacity hard carbon material. The high specific capacity hard carbon material prepared by the method has high reversible specific capacity, high initial coulombic efficiency and high rate capability, and excellent comprehensive sodium storage performance.

Inventors

  • LIU LING
  • Deng Jianji
  • MENG QINGHAN
  • ZHANG LIQUN

Assignees

  • 北京化工大学

Dates

Publication Date
20260505
Application Date
20241031

Claims (10)

  1. 1. A high specific capacity hard carbon material is prepared from raw materials including phenolic compounds, aldehyde compounds, catalysts and curing agents; the phenolic compound is at least one of aromatic compounds containing phenolic hydroxyl functional groups; The aldehyde compound is at least one of compounds containing aldehyde functional groups; The catalyst is at least one of acid catalysts; the curing agent is at least one of amine curing agents.
  2. 2. The high specific capacity hard carbon material according to claim 1, wherein: The phenolic compound is at least one of phenol, cresol, resorcinol, phloroglucinol, catechol and hydroquinone, and/or, The aldehyde compound is at least one of formaldehyde, acetaldehyde, furfural, benzaldehyde and phenylacetaldehyde, and/or, The catalyst is at least one of hydrochloric acid, sulfuric acid, formic acid, acetic acid, oxalic acid and phosphoric acid, and/or, The curing agent is diamine or polyamine with alicyclic ring, aromatic ring or heterocyclic ring.
  3. 3. The high specific capacity hard carbon material according to claim 2, wherein: The curing agent is at least one of melamine, hexamethylenetetramine, benzidine and phenylenediamine.
  4. 4. A method for preparing the high specific capacity hard carbon material according to any one of claims 1 to 3, comprising the steps of: (1) Uniformly mixing the phenolic compound, the aldehyde compound and the catalyst in water, and reacting to obtain a low molecular weight resin solution; (2) Adding the curing agent into the low molecular weight resin solution obtained in the step (1), uniformly mixing, and carrying out hydrothermal reaction to obtain high molecular weight crosslinked resin; (3) And (3) calcining the high molecular weight crosslinked resin obtained in the step (2) at a low temperature in an oxygen-containing gas atmosphere, calcining at a high temperature in a protective gas atmosphere, and cooling to room temperature to obtain the high specific capacity hard carbon material.
  5. 5. The method for preparing the high specific capacity hard carbon material according to claim 4, wherein: Step (1), The molar ratio of the phenolic compound to the aldehyde compound to the catalyst to the water is 1 (0.5-3): 0.01-0.2): 5-50, preferably 1 (0.6-1.2): 0.01-0.05): 15-30, and/or, The reaction temperature is 60 to 95 ℃, preferably 70 to 90 ℃, and/or, The reaction time is 1-3 h, and/or, The number average molecular weight of the low molecular weight resin is 400 to 50000, preferably 500 to 4000.
  6. 6. The method for preparing the high specific capacity hard carbon material according to claim 4, wherein: Step (2), The molar ratio of the amine curing agent to the phenolic compound is (0.01-2): 1, preferably (0.05-1): 1, more preferably (0.2-1): 1, and/or, The hydrothermal reaction is carried out in a pressurized closed device, and/or, The temperature of the hydrothermal reaction is 100-250 ℃, preferably 150-200 ℃, and/or, The hydrothermal reaction time is 2 to 15 hours, preferably 5 to 12 hours, and/or, The number average molecular weight of the high molecular weight crosslinked resin is 50000 or more, preferably 50000 to 100000.
  7. 7. The method for preparing the high specific capacity hard carbon material according to claim 4, wherein: Step (3), The oxygen-containing gas is at least one of oxygen, ozone and air, and/or, The aeration rate of the oxygen-containing gas is 0.1 to 5L/min, preferably 0.2 to 4L/min, and/or, The temperature rising rate of the low-temperature calcination is 0.5-20 ℃, preferably 1-10 ℃, more preferably 5-10 ℃, and/or, The low-temperature calcination temperature is 200-350 ℃, and/or, The low-temperature calcination time is 2-5 h.
  8. 8. The method for preparing the high specific capacity hard carbon material according to claim 4, wherein: Step (3), The protective gas is at least one of nitrogen and inert gas, and the inert gas is preferably argon, and/or, The temperature rising rate of the high-temperature calcination is 0.5-20 ℃ per minute, preferably 1-10 ℃ per minute, and/or, The high-temperature calcination temperature is 1200-1600 ℃, and/or, The high-temperature calcination time is 2-5 h.
  9. 9. A high specific capacity hard carbon material obtained by the production method according to any one of claims 3 to 8.
  10. 10. Use of a high specific capacity hard carbon material according to any one of claims 1 to 3,9 in a battery, preferably in a negative electrode material of a secondary battery, more preferably in a negative electrode material of a sodium ion battery.

Description

High specific capacity hard carbon material and preparation method and application thereof Technical Field The invention relates to the technical field of hard carbon materials, in particular to a high specific capacity hard carbon material and a preparation method and application thereof. Background In recent years, the demand for various portable electronic devices and hybrid vehicles has greatly increased, and the development and application of sodium ion batteries as lithium ion battery supplementary substitution products has also become an important point of current development. In the sodium ion battery cathode material, the hard carbon has larger reversible specific capacity, excellent cycle life, wide raw material source and lower cost. Biomass such as coconut shells, straw, lignin, starch, sucrose, etc., and synthetic resins such as phenolic resins are currently the primary precursor sources for hard carbon. Compared with biomass, the resin precursor has adjustable structure, high carbon residue rate and good sodium storage performance. The invention patent CN 118083950A prepares phenolic resin controllably by using monomeric phenol and monomeric aldehyde (one or more than two of paraformaldehyde, trioxymethylene or formaldehyde) under the action of catalyst, dissolves organic cross-linking agent (one of paraformaldehyde, terephthalaldehyde, maleic anhydride, succinic anhydride, trioxymethylene, acetyl chloride or terephthaloyl chloride) and the obtained phenolic resin in organic solvent and cures, calcines at low temperature under oxygen-containing atmosphere, and carbonizes at high temperature under inert atmosphere to obtain the product phenolic resin-based hard carbon material. The invention patent CN 113321202A is to react phenol monomer and aldehyde monomer to prepare phenolic resin emulsion, spray drying, pre-oxidizing and carbonizing to obtain hard carbon material. The invention patent CN117735521A is to heat treat the mixture of phenolic compound, aldehyde compound and amine compound, spray dry and carbonize to prepare the hard carbon cathode material. The invention patent CN 118206102A adds phenolic compound, amine compound and aldehyde compound into the solution, and sinters after heating reaction to obtain the hard carbon material. The invention patent CN 115072701A heats and stirs thermoplastic phenolic resin and alkali solution to obtain salt solution, removes water from the salt solution, and carbonizes the salt solution at high temperature to obtain the hard carbon anode material. The invention patent CN 115535998A is to react thermosetting phenolic resin, solvent water and catalyst, and to obtain hard carbon material through high temperature carbonization. The invention patent CN 109742383A is prepared by mixing phenolic resin as a precursor with ethanol, performing thermal curing by water, and performing mechanical crushing, carbonization and pyrolysis. The invention patent CN 118005003A phenolic resin and curing agent are subjected to heat treatment, pre-carbonization, blending with filler, annealing and carbonization to obtain the hard carbon material. At present, hard carbon precursor resin is mainly synthesized by phenol and aldehyde monomers, or thermoplastic or thermosetting resin is adopted for structural adjustment. The prepared hard carbon material has low specific capacity all the time, and restricts the large-scale application of sodium ion batteries. Therefore, the preparation of the hard carbon material with high specific capacity has important practical significance for developing the sodium ion battery with high energy density and high cycle stability. Disclosure of Invention In order to solve the technical problems in the prior art, the invention provides a high specific capacity hard carbon material, and a preparation method and application thereof. The hard carbon material has low specific capacity, which restricts the large-scale application of sodium ion batteries. The invention takes phenols and aldehydes compounds as raw materials, low molecular weight resin is obtained by reaction, amine curing agent is added to obtain high molecular weight resin, the obtained resin is calcined at low temperature in oxygen-containing atmosphere and calcined at high temperature in inert atmosphere to obtain hard carbon material with high specific capacity, and the reversible specific capacity and initial effect are both high. The invention adopts a two-step synthesis process to prepare low molecular weight resin liquid and then synthesize high molecular weight resin solid, wherein the synthesis of the high molecular weight resin is required to react in a closed container with certain pressure, such as a high-pressure reaction kettle, under the condition, the raw materials can react more fully, and the obtained product is more uniform. The amine curing agent adopted by the invention plays a role of N doping (such as melamine) during curing, can improve the defect degree of the