A carbon nanotube-coated cobalt oxide material and its preparation method and application

Abstract

The invention discloses a carbon nanotube-coated cobalt oxide material, a preparation method and application thereof. Co-PBA powder was prepared by using cobalt source, polyvinylpyrrolidone, water, and potassium cobalt cyanide, and then carbon nanotube-coated cobalt oxide materials were prepared by electrospinning technology and annealing. The carbon nanotube-coated cobalt oxide material in the present invention has a large specific surface area, which provides channels for ion transmission, improves the specific capacity and charge-discharge efficiency of lithium batteries; oxidizes the carbonized nano-spinning thread to obtain Co with higher activity 3 o 4 Carbon nanofibers improve the capacity of the entire battery; carbon nanotube-coated cobalt oxide materials have good morphology and Co 3 o 4 Its own properties can realize OER and ORR dual-function catalysts; the preparation and application methods of carbon nanotube-coated cobalt oxide materials are simple and easy to realize.

Description

technical field [0001] The invention belongs to the technical field of battery electrode materials, and in particular relates to a carbon nanotube-coated cobalt oxide material and a preparation method and application thereof. Background technique [0002] With the aggravation of energy crisis and environmental pollution problems, the development and application of new energy storage and conversion devices is imminent. Currently, energy storage and conversion devices mainly include supercapacitors, fuel cells, and secondary batteries. The most common secondary battery is a lithium-ion battery, which usually uses graphite as the negative electrode material, but the specific capacity of the graphite negative electrode material itself is not high, which limits the energy storage capacity of the lithium-ion battery. One class of fuel cells requires the use of catalytic technology, and the main commercial catalysts are still precious metal catalysts, and only for a single catalyt...

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Problems solved by technology

For example, Su et al. (Nanoscale, 2014, 6, 15080-15089) synthesized a spherical carbon-coated elemental cobalt material through a hydrothermal carbonization strategy, but this preparation method only uses polypyrrole as a polymer to polymerize cobalt acetate and then carbonize it. , the material does not have an organic framework structure (MOF) structure, and its shape is lumpy, which reduces the ion transmission rate and cannot provide a large number of active sites, and its preparation process is not suitable for industrial applications; Guo et al. (H.Guo, T.Li, W.Chen, L.Liu, X.Yang, Y.Wang, Y.Guo, Nanoscale 2014, 6, 15168) synthesized cubic CoFe 2 o 4 , but this material does not have a carbon-coated structure, resulting in a decrease in its conductivity, and does not have the mesoporous structure contained in carbon nanotubes, which leads to its non-adjustable pore size and insufficient ion transmission rate; Wang et al. silk synthesized a carbon-encapsulated hollow Co 3 o 4 Carbon nanofibers (J.Mater.Chem.A, 2019, 7, 3024-3030), but the fibers do not have a MOF-like structure as mentioned above, and a large amount of cobalt is used, resulting in a certain amount of waste

Most of the above metal oxide electrode materials only pay attention to the manufacture of hollow nanostructures, which have poor conductivity and are easily crushed and inactivated after volume expansion. Although carbon-coated materials solve the problem of easy crushing, their carbon structure is not connected, resulting in poor conductivity. For example, cobalt acetate or cobalt nitrate is directly used as cobalt source to synthesize Co 3 o 4 , which does not have an organic framework (MOF), which weakens the ion exchange rate and directly affects battery performance

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