Preparation method of carbon-coated lithium iron manganese phosphate graphene composite nanomaterial

Abstract

Disclosed is a preparation method of a carbon-coated lithium iron manganese phosphate graphene composite nanomaterial. The preparation method comprises the following steps of performing a mixed reaction on concentrated sulfuric acid, graphite, sodium nitrate and potassium permanganate and then adding deionized water and hydrogen peroxide, performing cleaning and drying by diluted hydrochloric acidand deionized water to obtain graphite oxide, and adding the graphite oxide into deionized water to be subjected to mixing treatment to obtain a graphene oxide water suspension liquid; taking a lithium source, a phosphorus source and an admixture of manganese source and an iron source, enabling the lithium source to be dissolved into ethylene glycol, and adding the graphene oxide water suspensionliquid; enabling the admixture of the manganese source and iron source to be dissolved into the deionized water, adding the graphene oxide water suspension liquid and performing diluting by ethyleneglycol; enabling the phosphorus source to be dispersed into ethylene glycol, performing adding until a third mixture is changed into a seventh mixture, and a fifth mixture is changed into a seventh mixture, and then removing SO<4><2-> to obtain a lithium iron manganese phosphate graphene composite precursor; and performing dispersion on the lithium iron manganese phosphate graphene composite precursor, then adding a carbon source and putting into a mixed gas to obtain the carbon-coated lithium iron manganese phosphate graphene composite nanomaterial.

Description

【Technical field】 [0001] The invention relates to the technical field of battery cathode materials, in particular to a method for preparing a carbon-coated lithium iron phosphate lithium manganese graphene composite nanomaterial. 【Background technique】 [0002] After years of development, lithium batteries have been widely used in many fields, but the electrochemical performance of lithium batteries is not enough to meet the current needs. How to improve the electrochemical performance of lithium batteries has become a hot and difficult research topic. The positive electrode material of the lithium battery directly affects the electrochemical performance of the lithium battery. Therefore, in recent years, a lot of research has been devoted to cathode materials for lithium batteries. LiMnPO as cathode material 4 Compared to LiFePO as the cathode material 4 It has the advantages of high working voltage, low self-discharge rate, mature material and low cost. The two have th...

AI Technical Summary

Problems solved by technology

In view of the above problems, however, the modification methods implemented include three methods: surface coating, composite material preparation, and nanonization. Using a single modification method, it is difficult to obtain a positive electrode material with ideal performance. Therefore, it is necessary to obtain a positive electrode with excellent electrochemical performance. materials, it is necessary to use double or even multiple modification methods to modify lithium iron phosphate manganese

Images