Porous spherical carbon-coated sodium vanadium phosphate composite positive electrode material and preparation method thereof

Abstract

Disclosed are a porous spherical carbon-coated sodium vanadium phosphate composite positive electrode material and a preparation method thereof. The composite positive electrode material is prepared by the steps of (1) dissolving a vanadium source compound and a reducing agent into water, performing heating and then adding a phosphorus source compound and a sodium source compound to obtain a mixedsolution; (2) adding an organic solvent, wherein the polarity of the organic solvent is greater than that of water, and putting into a sealed container to be subjected to a heating reaction, and next, performing cooling, centrifuging, washing, depositing and drying to obtain precursor powder; and (3) performing mixing with glucose, and performing sintering and cooling on the mixture in protectiveatmosphere. The positive electrode material is spherical and has the primary granular diameter of 50-200nm; when the composite positive electrode material is assembled into a battery, the initial discharge capacity per gram at 0.2C and 10C within a voltage range of 2.0-3.8V can reach 110 mAh.g<-1> and 95 mAh.g<-1> respectively; the capacity retention rate can reach 99.47% at 10C rate after 100 cycles; and the method is simple and low in reaction temperature.

Description

technical field

[0001] The invention relates to a sodium vanadium phosphate composite positive electrode material and a preparation method thereof, in particular to a porous spherical carbon-coated sodium vanadium phosphate composite positive electrode material and a preparation method thereof. Background technique

[0002] With the consumption of non-renewable fossil energy such as oil and natural gas, the arrival of the energy crisis has attracted more and more attention. In this context, green and non-polluting new high-energy chemical power sources have become a hot spot in the development of countries all over the world.

[0003] Lithium-ion battery is a new type of chemical power source, which is composed of two compounds that can reversibly insert and extract lithium ions as positive and negative electrodes. However, with the rapid development of lithium-ion batteries, the demand for metal lithium is increasing, but lithium resources are limited. Therefore, the cost ...

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