Process for producing carbon coated iron lithium phosphate

Abstract

The invention relates to a preparation method of lithium iron phosphate for the carbon cladding of a lithium ion battery. The prior lithium iron phosphate preparation technical art is complex, and has high cost. The invention has the synthetic process that: ferric oxide, phosphoric acid, simple organics and doped element compound are mixed and dried, the mol ratio of phosphate radical ion, ferric ion and doped element ion is 1:y:z, wherein, y is larger than or equal to 0.95 and smaller than or equal to 1, and y plus z is equal to 1; the mixture is added with lithium source compound, added with water to be mixed and dried, the mol ratio of lithium ion and phosphate radical ion is x:1, and x is larger than or equal to 0.95 and smaller than or equal to 1.05; the mixture which reacts for 2 to 20 hours under 500 to 800 DEG C is cooled in a furnace. The invention finally produces the precursor uniformly mixed with superfine crystal grain, and during the subsequent high temperature solid phase reaction, the end product lithium iron phosphate can be produced through shorter distance diffuseness of atoms. The end product has high purity, the crystallisation is good, the capacity is high, and the cycle stability is good.

Description

technical field [0001] The invention belongs to the technical field of energy materials, and in particular relates to a preparation method of carbon-coated lithium iron phosphate used for lithium-ion batteries. technical background [0002] Lithium-ion batteries are an excellent battery system. It has the characteristics of high energy density, no memory effect, no pollution, and long life. With the advancement of lithium-ion battery technology, it also has the characteristics of high safety and can be made into any shape, so it is an ideal energy storage device. [0003] Lithium-ion batteries are widely used in various electronic devices, such as laptop computers, mobile phone batteries, digital cameras, portable lighting equipment, etc. At the same time, it is also used in electric tools, electric bicycles and electric vehicles. With the gradual consumption of the world's oil resources and the gradual improvement of society's requirements for environmental protection, e...

AI Technical Summary

Problems solved by technology

In the process of raw material production, storage and transportation, measures need to be taken to prevent the oxidation of divalent iron source, so the cost is high

In this case, even after a long time of heat preservation, the raw material cannot completely generate lithium iron phosphate

In order to refine ferric oxide, high-energy ball milling equipment is required for long-term ball milling, which requires high equipment, high energy consumption, and loud noise

Moreover, when the amount of material increases, the efficiency of high-energy ball mill equipment decreases sharply, making it difficult to realize industrial production.