A carbon coating method for in-situ growth of metal-organic complexes on electrode surface

Abstract

The invention provides a carbon coating method for in situ growth of a metal organic complex on the surface of an electrode, and belongs to the field of hydrogen storage materials. The method comprises the following steps: uniformly mixing Ti1.4V0.6Ni quasicrystal powder with nickel carbonyl powder according to a mass ratio of 1:5, carrying out cold static pressing with a tablet press to form a circular electrode with the diameter of 10mm and the thickness of 1mm, generating polydopamine on the surface of the electrode through polymerization, realizing in situ growth of a metal organic complex ZIF-67 on the surface of the polydopamine, and charring the obtained electrode under the protection of argon and hydrogen mixed atmosphere to obtain an electrode with the surface being coated with a metal organic complex carbon skeleton. An experiment result shows that the capacity attenuation rate of the electrode with the surface being coated with the metal organic complex carbon skeleton is lower than that of electrodes without the metal organic complex after charge and discharge cycle for 100 weeks.

Description

technical field [0001] The invention belongs to the technical field of hydrogen storage materials, and in particular relates to a carbon coating method for in-situ growth of metal-organic complexes on an electrode surface. Background technique [0002] Carbon coating modification is an effective way to improve the conductivity of electrode materials. One type is directly added to the precursor to form a carbon coating layer in situ during the sintering process of the sample, and the other type is to perform carbon coating treatment after the sample is obtained. , carbon coating is widely used in the field of lithium-ion batteries and supercapacitor materials, as shown in Table 1, using different carbon sources and different addition methods, the results obtained are also different. [0003] Table 1 Representative results of carbon coating of battery materials [0004] [0005] In an alkaline electrolyte environment, it is difficult to coat materials with carbon, but ther...

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Problems solved by technology

[0012] On January 28, 2015, the Chinese Patent Office published the CN 104307482 patent titled "Functionalized ZIF-type metal-organic framework porous material, its preparation method and application", which provides a functionalized ZIF-type metal-organic framework porous material, and its skeleton contains Metal zinc ion or cobalt ion, the advantage of this invention is that this material has good physical and chemical stability, to CO 2 It has good adsorption performance, and at the same time, the material has good electrochemical performance as an electrode material for lithium-ion batteries. After N cycles (N is greater than or equal to 10), the discharge specific capacity of lithium-ion batteries is maintained at the Nth discharge specific capacity. More than 95%, but the functionalization research of ZIF-type metal-organic framework materials in this patent is limited to lithium-ion batteries in the field of electrochemical batteries, and it is also limited to CO in terms of gas adsorption. 2 , while the functionalization research and hydrogen absorption and desorption application of ZIFs in the field of nickel-metal hydride secondary batteries have not been involved

[0019] On December 21, 2005, the Chinese Patent Office published the CN1709564A patent titled "An Icosahedral Titanium Reference Crystal Material with Hydrogen Storage Function and Its Preparation Method". It takes 5h to 6h to obtain the quasicrystal phase. Therefore, the temperature at which the phase transition of the quasicrystal occurs must be at least higher than 600°C, but the actual temperature of the battery is mostly between -20°C and +40°C, and the temperature of the catalytic hydrogenation reaction is also low. will be higher than 600°C; although the invention reveals the possibility of using the quasicrystal alloy in batteries or catalytic hydrogenation reactions, and the quasicrystal also exhibits a high hydrogen storage capacity, it is difficult to prepare single-phase quasicrystals, and the distance The application is still far away;

[0020] On September 1, 2010, the Chinese Patent Office published the CN101816915A patent titled "Amorphous Icosahedral Quasicrystalline Hydrogen Storage Alloy and Its Quenching Preparation Method". Hydrogen alloy, the reversible hydrogen absorption and desorption capacity of the quasicrystal is close to 2.3mass%. The performance of chemical hydrogen storage is mediocre, and the alloy system contains precious metal palladium, which has a high cost;

[0021] On September 22, 2015, the Chinese Patent Office published a patent titled "A Aluminum-Containing Sodium Titanium Vanadium Nickel Quasicrystal Composite Hydrogen Storage Material and Its Preparation Method" 201210552733.7 patent. The advantage of this invention is: the method of mechanical alloying in Ti 1.4 V 0.6 Adding aluminum, sodium and other elements to the Ni quasicrystal powder increases the entropy change of the quasicrystal composite hydrogen storage alloy, and the electrochemical maximum discharge capacity of the quasicrystal hydrogen storage material containing aluminum, sodium, titanium, vanadium and nickel reaches 299.2mAh g -1 At the same time, the cycle life of the battery has also been significantly improved, which broadens the idea for the further application of titanium-based crystalline hydrogen storage alloys, but the energy of the mechanical alloying process is relatively high, and it is easy to make Ti 1.4 V 0.6 The icosahedral quasicrystal phase in the Ni quasicrystal undergoes an amorphous transformation, resulting in the destruction or disappearance of the quasicrystal structure

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