A carbon-sulfur composite electrode and secondary battery based on graphene array

A graphene array, carbon-sulfur composite technology, applied in secondary batteries, battery electrodes, non-aqueous electrolyte battery electrodes, etc., can solve the problem that the advantages of graphene materials cannot be reflected, the electrical conductivity cannot be maximized, and the surface area of ​​the conductive network is reduced. and other problems, to achieve the effect of improving the electrochemical utilization rate, reducing the shuttle effect, and improving the cycle performance.

Inactive Publication Date: 2017-05-24
NANJING ZHONGCHU NEW ENERGY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The carbon atoms in the ideal carbon nanotube and graphene structures are both sp 2 The hybrid bonding method, both of which have a huge specific surface area, extremely high mechanical strength and excellent electron transport ability, can effectively improve the electrical conductivity of the composite material, but in practical applications, because graphene is extremely prone to agglomeration, Graphene sheets are easy to stack, resulting in greatly reduced surface area of ​​its conductive network, low specific capacity and low rate, which cannot reflect the advantages of graphene material itself
However, carbon nanotubes and sulfur composite materials are also in a disordered stacking state of carbon nanotubes, resulting in uneven sulfur loading and high contact resistance. The advantages of carbon nanotube tubular materials cannot be fully utilized, and their electrical conductivity cannot be maximized.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0041] (1) Preparation of graphene array: 30 μm thick nickel current collector is used as the substrate and placed in the quartz glass tube of the tubular resistance furnace, and 1000 sccm of argon and hydrogen gas mixture is introduced, wherein the volume ratio of hydrogen is 1%, and the temperature is raised at the same time to 650°C; adjust the voltage to 10kV to generate stable glow plasma to remove impurities on the surface of the substrate. After 10 minutes, feed 150 sccm methane and 1350 sccm argon, and feed water vapor at the same time, control the relative humidity at 40%, and then stop feeding Mixed gas of argon and hydrogen, reacted for 20 minutes, cooled down to room temperature in a reducing atmosphere after the end, and took it out for later use.

[0042](2) Composite carbon nanotubes: Electron beam evaporation is used to coat the surface of the graphene array with silicon with a thickness of about 20nm as a transition layer, and then coated with a Fe catalyst wit...

Embodiment 2

[0047] (1) Preparation of graphene array: use a stainless steel substrate, attach iron powder to its surface, place it in a chemical vapor deposition chamber, and seal it; apply a magnetic field in the vertical direction of the substrate, the magnetic field strength is 0.01T, and pass 50 sccm argon gas for 30 minutes In order to exclude oxygen in the reaction chamber, heat the substrate to 700°C, and then pass 100 sccm of methane into it for 1 hour. After the reaction, stop the heating, turn off the methane, cool to room temperature under the protection of argon, and take out the product and wash it with 1mol / L hydrochloric acid. Dry and set aside.

[0048] (2) The method of compounding carbon nanotubes is the same as that in Example 1.

[0049] (3) Composite sulfur: heat the elemental sulfur to a molten state, put the prepared graphene array composite material with carbon nanotubes into it under the protection of argon, keep it for 8 hours, take it out, put it in an oven at 4...

Embodiment 3

[0052] The methods of graphene array and composite carbon nanotubes are the same as in Example 1.

[0053] Composite sulfur: dissolve sulfur in an organic solvent such as carbon disulfide to form a sulfur-containing solution, place the graphene array composite material grown with carbon nanotubes in it for impregnation, and obtain a composite electrode after drying.

[0054] The preparation and testing methods of the battery are the same as in Example 1. The measured open circuit voltage of the battery is 1.69V, the first discharge capacity is 890mAh, and after 50 charge and discharge cycles, the capacity retention rate is 80.7%.

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PUM

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Abstract

The invention discloses a composite electrode comprising a graphene array, carbon nanotubes and sulfur and a preparation method thereof and also discloses a secondary aluminum cell utilizing the composite electrode as a positive pole. The composite electrode is obtained by compounding of sulfur and a graphene array with the carbon nanotubes growing on the graphene array surface, has a very large specific surface area and a three-dimensional network conductive skeleton, and can effectively improve active substance sulfur load capacity and utilization rate. The secondary aluminum cell has a high specific capacity and good circularity.

Description

technical field [0001] The invention belongs to the field of battery material science, and relates to a graphene array / carbon nanotube / sulfur composite electrode and its preparation method, and its application in secondary aluminum batteries. Background technique [0002] With the rapid development of new power sources such as electronic and communication equipment, electric vehicles, wind power and photovoltaic power generation, human beings have higher and higher demands on battery performance for supporting power sources, and there is an urgent need to develop power batteries and energy storage batteries. The theoretical volume specific capacity of aluminum is 8050mAh / cm 3 , is 4 times that of lithium, and the chemical activity is stable, it is an ideal negative electrode material; the theoretical volume specific capacity of sulfur is 3467mAh / cm 3 , is one of the positive electrode materials with the highest known energy density. Therefore, aluminum-sulfur batteries have...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01M4/13H01M10/054
CPCH01M4/587H01M4/625H01M10/054Y02E60/10
Inventor 赵宇光钟毓娟
Owner NANJING ZHONGCHU NEW ENERGY
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