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CN-122025427-A - Cellulose acetate derived carbon fiber based electrode, preparation method and application

CN122025427ACN 122025427 ACN122025427 ACN 122025427ACN-122025427-A

Abstract

The invention discloses a preparation method of an acetate cellulose derivative carbon fiber-based electrode, which comprises the steps of preparing a fiber felt by electrostatic spinning of acetate cellulose, immersing the fiber felt in a zinc acetate solution, and performing pre-oxidation, carbonization and acid washing treatment to obtain the acetate cellulose derivative carbon nanofiber, wherein the preparation method does not comprise a deacetylation treatment step. The preparation method solves the technical problems of complex preparation process, serious pollution, low carbon yield and easy collapse of morphology of the existing cellulose acetate carbon fiber. The carbon yield of the obtained carbon nanofiber is more than or equal to 45%, the carbon nanofiber has a flexible self-supporting structure, and the carbon yield can reach 49.7%, which is far higher than that of a comparison sample (33.12%) which is not treated or is only treated by zinc chloride. When the zinc ion mixed capacitor is used as a positive electrode material of a zinc ion mixed capacitor, the specific capacity reaches 183 mAh/g under the current density of 0.2A/g, and the capacity retention rate reaches 95.2% after the zinc ion mixed capacitor is cycled for 75000 times under the current density of 10A/g. The method has simple process, is green and environment-friendly, and is suitable for large-scale production.

Inventors

  • TANG SHAOCHUN
  • YANG GUANGJIE
  • CAO XUAN

Assignees

  • 南京大学
  • 海安南京大学高新技术研究院

Dates

Publication Date
20260512
Application Date
20260410

Claims (7)

  1. 1. The preparation method of the cellulose acetate derived carbon fiber based electrode is characterized by comprising the following steps of: step 1 preparing cellulose acetate fiber felt Carrying out electrostatic spinning on cellulose acetate to obtain a cellulose acetate fiber felt, and preparing cellulose acetate derivative carbon nanofiber in step 2 ① Dipping the cellulose acetate fiber felt in the step 1 into zinc acetate solution to obtain a dipped fiber felt; ② Pre-oxidizing the impregnated fiber mat in an air atmosphere, and carbonizing in an inert atmosphere to obtain a carbonized product; ③ And carrying out acid washing treatment on the carbonized product, and drying to obtain the cellulose acetate derivative carbon nanofiber, wherein the preparation method does not comprise a deacetylation treatment step.
  2. 2. The method according to claim 1, wherein in the step 2, the solvent of the zinc acetate solution is water or a mixed solvent of water and ethanol.
  3. 3. The preparation method of claim 2, wherein in the mixed solvent of water and ethanol, the volume ratio of water to ethanol is 1-5:1.
  4. 4. The method of claim 1, wherein in step 2, the time of the impregnation is 20 to 28 h.
  5. 5. The method according to claim 1, wherein in step 2, the pre-oxidation treatment is performed at a temperature of 180 to 220 ℃ and the carbonization treatment is performed at a temperature of 700 to 900 ℃.
  6. 6. The cellulose acetate derivative carbon nanofiber prepared by the preparation method according to any one of claims 1 to 5, wherein the carbon yield of the cellulose acetate derivative carbon nanofiber is more than or equal to 45%, and the cellulose acetate derivative carbon nanofiber has a flexible self-supporting structure.
  7. 7. A zinc ion hybrid capacitor comprising the cellulose acetate derived carbon nanofiber as defined in claim 6 as a positive electrode material.

Description

Cellulose acetate derived carbon fiber based electrode, preparation method and application Technical Field The invention belongs to the technical field of electrode preparation, and particularly relates to a cellulose acetate derived carbon fiber based electrode, a preparation method and application thereof. Background With the rapid development of electric vehicles and intelligent electronic devices, the market has created an urgent need for electrochemical energy storage systems that have a combination of high energy density, high power density, long cycle life, and high safety. The Zinc Ion Hybrid Capacitor (ZIHCs) combines the high-energy storage characteristic of the battery type negative electrode and the rapid response characteristic of the capacitor type positive electrode, and the water-based electrolyte further improves the safety, so that the zinc ion hybrid capacitor becomes a research hot spot of a novel energy storage device. Carbon materials are widely used as ZIHCs positive electrode materials because of their good conductivity, excellent chemical stability and low cost. Among the numerous carbon precursors, cellulose Acetate (CA) is an ideal biomass carbon source with a wide range of sources, a high carbon content, and an oxygen content. Cellulose Acetate (CA) can be obtained through a simple esterification reaction of cellulose, is one of cellulose derivatives with highest global yield, has annual yield of over million tons and is widely applied to the fields of spinning, membrane separation and biological medicine. In view of its significant cost advantages, CA-based electrode materials are considered ideal choices for energy storage devices. However, CA molecular chains contain a large number of very cleavable acetyl groups and lack cyclizable cross-linking functionality, failing to form a stable graphite crystallite skeleton during carbonization. And, the CA derivative nanofiber has low carbon yield after high-temperature carbonization, and poor structural stability and mechanical property, which severely limits the application of the CA derivative nanofiber. In the prior art, in order to obtain the CA derivative carbon fiber with complete morphology, strong alkali (such as NaOH) is needed to be used for deacetylation treatment in advance to convert the CA into cellulose with higher thermal stability. The process has the following defects that (1) the deacetylation process takes longer time and usually takes more than 12 hours, (2) a great amount of alkaline waste liquid is generated by using a strong alkali reagent, the environmental pollution is serious, and (3) the process flow is complicated, the production cost is increased, and the large-scale application is not facilitated. Therefore, the CA derived carbon fiber preparation strategy which does not need deacetylation treatment, has a simple process and is environment-friendly is developed, and has important significance for promoting the industrialization of high-performance ZIHCs carbon-based positive electrodes. Disclosure of Invention The invention provides a cellulose acetate derived carbon fiber based electrode, a preparation method and application, and solves the technical problems of complex preparation process, serious pollution, low carbon yield and easy collapse of morphology of the existing cellulose acetate carbon fiber by combining electrostatic spinning with zinc acetate impregnation and direct carbonization without deacetylation. The invention provides a cellulose acetate derived carbon fiber based electrode, a preparation method and application thereof, comprising the following steps: step 1 preparing cellulose acetate fiber felt Carrying out electrostatic spinning on cellulose acetate to obtain a cellulose acetate fiber felt, and preparing cellulose acetate derivative carbon nanofiber in step 2 ① Dipping the cellulose acetate fiber felt in the step 1 into zinc acetate solution to obtain a dipped fiber felt; ② Pre-oxidizing the impregnated fiber mat in an air atmosphere, and carbonizing in an inert atmosphere to obtain a carbonized product; ③ And carrying out acid washing treatment on the carbonized product, and drying to obtain the cellulose acetate derivative carbon nanofiber, wherein the preparation method does not comprise a deacetylation treatment step. Preferably, in step 2, the solvent of the zinc acetate solution is water or a mixed solvent of water and ethanol. Preferably, in the mixed solvent of water and alcohol, the volume ratio of water to alcohol is 1-5:1. Preferably, in step 2, the time of the impregnation is 20-28 h. Preferably, in step 2, the temperature of the pre-oxidation treatment is 180-220 ℃, and the temperature of the carbonization treatment is 700-900 ℃. The invention also provides the cellulose acetate derivative carbon nanofiber prepared by the preparation method of any one of the above, wherein the carbon yield of the cellulose acetate derivative carbon nanofiber is more than or equal to