Preparation method of octahedral porous molybdenum dioxide and application of octahedral porous molybdenum dioxide in lithium-ion battery

Abstract

The invention discloses a preparation method of octahedral porous molybdenum dioxide and an application of the octahedral porous molybdenum dioxide in a lithium-ion battery. The preparation method comprises the steps of: adding trimesic acid and tetramethyl ammonium hydroxide to a solution containing a copper salt and a phosphomolybdic acid and / or phosphomolybdate for stirring to form an emulsion; transferring the emulsion into a hydrothermal reaction kettle for hydrothermal reaction to obtain a precursor compound; and putting the precursor compound into a protective atmosphere, carrying out thermal treatment at a high temperature and then washing the product to obtain a porous octahedral molybdenum dioxide material which is formed by stacking and assembling ultrafine nanoparticles, is uniform in shape and form and good in stability and has a porous characteristic. The molybdenum dioxide material is applied to the lithium-ion battery as a negative electrode material, so that the rate capability and the cycling stability of the electrode material are improved under the premise of ensuring the specific capacity; the preparation technology of the molybdenum dioxide material is simple; the cost is low; and the molybdenum dioxide material has a relatively good research prospect.

Description

technical field [0001] The invention relates to a preparation method of a negative electrode material of a lithium ion battery, in particular to the preparation of an octahedral porous molybdenum dioxide and its application in a lithium ion battery, belonging to the field of new energy materials. Background technique [0002] As an electrochemical energy storage device that occupies a dominant position in society, lithium-ion batteries have achieved rapid development in portable electronic products (notebook computers, smart mobile equipment, tablet computers, etc.) and electric vehicles, and have shown good development prospects . Graphite has been commercially used as the anode of lithium-ion batteries due to its cheapness and good stability, but its capacity is still low. [0003] Recently, transition metal oxides have attracted attention in the field of lithium-ion batteries because of their relatively high theoretical specific capacity. Among these oxides, molybdenum d...

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Problems solved by technology

Shi et al. (Nano Letters, 2009, 9, 4215.) reported using silicon dioxide as a template to prepare nanometer mesoporous molybdenum dioxide by gas phase technology under 10% hydrogen atmosphere conditions. When applied to lithium-ion batteries Exhibited 750nAhg -1 specific capacity, but the preparation method is expensive, the synthesis conditions are harsh, and hydrogen gas with potential safety hazards is required, so it is difficult to achieve mass production; Zhao et al. (J.Mater.Chem., 2012, 22, 13334.) reported a Molybdenum dioxide with a core-shell structure synthesized by a solvothermal method, and applied to the negative electrode of lithium-ion batteries, its first-cycle specific capacity is 749.3mAhg -1 , reduced to 623.8mAhg after 50 laps -1 , although the performance is relatively good, but the core-shell structure is relatively complex, and the morphology structure is not easy to control, which limits its large-scale application; Chinese patent CN 102815749A discloses a method for preparing molybdenum dioxide nanorods by co-precipitation method, which The synthesis conditions of this method are difficult to control, and the uniformity of the material morphology is poor.

[0005] Most of the above-mentioned preparation methods of molybdenum dioxide have the disadvantages of harsh synthesis conditions and difficult control of morphology and material uniformity. When they are used as lithium-ion battery negative electrode materials, some have poor cycle stability and some have unsatisfactory high-current performance. Therefore, there is an urgent need to explore a negative electrode material for lithium-ion batteries with good capacity performance, good cycle and rate performance, and simple preparation methods in this field.

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