Preparation method of nano graphite powder/carbon nanofiber composite electrode for all-vanadium redox flow battery

An all-vanadium redox flow battery and nano-graphite powder technology, applied in battery electrodes, circuits, electrical components and other directions, can solve the problems of low surface activity of electrode materials and unstable electrocatalytic performance of electrode materials, and achieve electrochemical activity improvement, The effect of increased roughness and improved energy efficiency

Inactive Publication Date: 2015-01-28
INST OF METAL RESEARCH - CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The object of the present invention is to provide a kind of preparation method of nano-graphite powder / nano-carbon fiber composite electrode for all-vanadium redox flow battery, solve the electrode reaction of all-vanadium redox flow battery existing in the prior art in electrode material surface activity is low, electrode material is limited Unstable electrocatalytic performance and other issues

Method used

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Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0015] In a specific embodiment of the present invention, the preparation method of nano-graphite powder / nano-carbon fiber composite electrode for all-vanadium redox flow battery comprises the following steps and process method:

[0016] 1) Preparation of spinning solution: adding polyacrylonitrile or polyethylene glycol into dimethylformamide or dimethylacetamide in a certain proportion, stirring evenly under water bath conditions;

[0017] Among them, the average molecular weight of polyacrylonitrile is 50,000-200,000, the average molecular weight of polyethylene glycol is 2,000-10,000, and the mass ratio of polyacrylonitrile or polyethylene glycol to dimethylformamide or dimethylacetamide is 5 : 95 to 20: 80 (preferably 10: 90 to 15: 85), the water bath temperature is 40 ~ 80 ° C, the stirring time of polyacrylonitrile or polyethylene glycol in dimethylformamide or dimethylacetamide 0.5 to 24 hours (preferably 3 to 6 hours).

[0018] 2) Adding nano-graphite powders of diff...

Embodiment 1

[0031] 1) Add polyacrylonitrile with a mass fraction of 10% into dimethylformamide with stirring, and stir for 2 hours at a water bath temperature of 60° C. to obtain a composite spinning solution. The average molecular weight of polyacrylonitrile is 150,000.

[0032] 2) Add graphite powder with a particle size of 500nm to the spinning solution, the mass ratio of the added graphite powder to the polyacrylonitrile in the solution is 1:100, stir for 12 hours, and then ultrasonic for 6 hours to obtain a uniform composite spinning solution.

[0033] 3) adding the composite spinning solution obtained in step 2) into a 20ml syringe, and using electrospinning technology to obtain a nanofiber membrane, the thickness of the nanofiber membrane is 0.5 mm;

[0034] Among them, the parameters of the electrospinning process are as follows: the aperture of the needle head is 0.3 mm, the distance between the needle head and the nanofiber film collecting plate on the rotating roller is 12 cm, ...

Embodiment 2

[0039] The difference from Example 1 is:

[0040] 1) Polyethylene glycol with a mass fraction of 10% was added to dimethylformamide under stirring conditions, and the temperature of the water bath was stirred at 40° C. for 3 hours to obtain a composite spinning solution. The average molecular weight of polyethylene glycol was 8000.

[0041] 2) Add graphite powder with a particle size of 500nm to the spinning solution, the mass ratio of the added graphite powder to the polyacrylonitrile in the solution is 1:100, stir for 12 hours, and then ultrasonic for 6 hours to obtain a uniform composite spinning solution.

[0042] 3) adding the composite spinning solution obtained in step 2) into a 20ml syringe, and using electrospinning technology to obtain a nanofiber membrane, the thickness of the nanofiber membrane is 0.5 mm;

[0043] Among them, the parameters of the electrospinning process are: the aperture of the needle head is 0.6 mm, the distance between the needle head and the nan...

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Abstract

The invention relates to the field of battery manufacturing and energy source storage, in particular to a preparation method of a nano graphite powder/carbon nanofiber composite electrode for an all-vanadium redox flow battery. Firstly, a spinning solution required by an experiment is prepared, and then nano graphite powder with different particle sizes and the spinning solution are uniformly mixed. By an electrospinning technology, a required nanofiber membrane is prepared, and then is pre-oxidized in the air and is carbonized in an inert atmosphere tubular atmosphere furnace to obtain a required nano graphite powder/carbon nanofiber composite electrode. According to the all-vanadium redox flow battery composite electrode prepared by the method provided by the invention, the carbon fiber diameter is at the nanoscale, and the carbon fiber is compounded with nano graphite powder with high electrical conductivity, so that the roughness of the fiber is substantially increased, and thus the specific surface area of the electrode is two orders of magnitude larger than that of the conventionally used electrode material. Meanwhile, the high-activity nano graphite powder enables the electrochemical activity of the electrode to be improved, so that the energy efficiency of the all-vanadium redox flow battery is greatly improved.

Description

technical field [0001] The invention relates to the fields of battery manufacturing and energy storage, in particular to a method for preparing a nano-graphite powder / nano-carbon fiber composite electrode for an all-vanadium redox flow battery. Background technique [0002] The all-vanadium redox flow battery is a new type of secondary battery that utilizes the chemical changes in different valence states of vanadium ions to store energy. The electrochemical polarization is reduced, and its rated power and rated power can be designed separately. Instantaneous charging can be achieved by replacing the electrolyte, and 100% deep discharge will not damage the battery. Based on the above advantages, it can be widely used in wind energy, solar energy and other energy storage, power grid peak regulation, uninterruptible power supply, etc. [0003] At present, the electrode materials used in all-vanadium redox flow batteries are mainly carbon-based graphite felt or carbon felt, wh...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/88
CPCH01M4/88Y02E60/50
Inventor 刘建国魏冠杰严川伟
Owner INST OF METAL RESEARCH - CHINESE ACAD OF SCI
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