A kind of lithium iron phosphate with flower-like structure and preparation method thereof

Abstract

The invention discloses lithium iron phosphate with a flower-like structure and a preparation method thereof. Flower-like lithium iron phosphate is characterized in that lithium iron phosphate powder has average particle size about 5-100 mu m. Lithium iron phosphate is prepared by the following method: (1) firstly weighing lithium salt, iron salt and phosphate according to certain molar stoichiometric proportion, and dissolving in deionized water to prepare a solution with the ratio of Li<+> to Fe<2+> to PO4<3-> being 3:1:1 to 1:1:1 and Fe ion concentration being 0.02-0.5M; (2) slowly adding a pH regulator to the solution obtained in the step (1) to adjust the pH value to 8-10; (3) adding the pH-adjusted solution obtained in the step (2) to a 100mL polytetrafluoroethylene inner lining at a filling degree of 50-80%, placing the inner lining in a stainless steel hydrothermal kettle, then placing a program control temperature box for heat treatment, controlling the temperature at 120-200 DEG C to carry out continuous reaction for 6-60 hours, and after heat treatment is finished, carrying out suction filtering and separation to obtain a grey precipitate; and (4) cleaning the precipitate obtained in the step (3) with deionized water for multiple times, placing in the program control temperature box, and drying at 60-100 DEG C for 10-24 hours to finally obtain flower-like lithium iron phosphate with different particle sizes. The obtained lithium iron phosphate specimen can be used as a cathode material of a lithium ion cell.

Description

technical field [0001] The invention relates to lithium iron phosphate with a flower-like structure in the field of lithium ion batteries and a preparation method thereof. Background technique [0002] Due to the advantages of high voltage, high capacity, long cycle life, and good safety performance, lithium-ion batteries have broad application prospects in portable electronic devices, electric vehicles, and space technology. Of which LiFePO 4 The material is the most eye-catching, because it not only has the advantages of wide source of raw materials, cheap price, non-toxic, and environmental friendliness, but also LiFePO 4 It has the advantages of stable structure, good thermal stability and high safety, and more importantly, its theoretical capacity is as high as 170mAhg -1 , therefore, in recent years LiFePO 4 It has been developed rapidly and has certain practical applications, especially in power batteries. It has a good application prospect. At present, the most co...

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Problems solved by technology

Of which LiFePO 4 The material is the most eye-catching, because it not only has the advantages of wide source of raw materials, cheap price, non-toxic, and environmental friendliness, but also LiFePO 4 It has the advantages of stable structure, good thermal stability and high safety, and more importantly, its theoretical capacity is as high as 170mAhg -1 , therefore, in recent years LiFePO 4 It has been developed rapidly and has certain practical applications, especially in power batteries. It has a good application prospect. At present, the most commonly used LiFePO 4 Powder particles are usually composed of irregular particles, and their tap density and volume specific capacity are low, which affects their industrialization process

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