A kind of preparation method of tin oxide coated cobalt magnesium lithium material

Abstract

The invention discloses a method for preparing a stannic-oxide-wrapped cobalt magnesium lithium material. The method includes the following steps: cobalt salt and magnesium salt are dissolved into water, stabilizers are added to be mixed, a solution A is obtained, the solution A and precipitators are added into a reaction container at the same time for carrying out co-precipitation, purifying processing, heat nature determining processing and sub-high temperature processing are carried out on sediment to obtain cobalt magnesium oxide; the cobalt magnesium oxide is mixed with LiOH.H2O, absolute ethyl alcohol is added, ball milling is carried out in a planetary ball mill, filtering and drying are carried out, the obtained powder material is loaded into a porcelain boat, the porcelain boat with the powder material is pushed into a resistance furnace to be sintered, and a cobalt magnesium lithium material is obtained after cooling is carried out; the obtained cobalt magnesium lithium material is mixed with SnCl2.2H2O and deionized water, the mixture is evenly stirred, ultrasonic processing, filtering and drying are carried out, and the stannic-oxide-wrapped cobalt magnesium lithium material is obtained after roasting is carried out in a muffle furnace. The prepared stannic-oxide-wrapped cobalt magnesium lithium material is stable in electrochemical performance, stable in crystal lattice, large in tap density and good in cycle performance and rate performance.

Description

Technical field: [0001] The invention relates to the technical field of lithium ion batteries, in particular to a preparation method of a tin oxide-coated cobalt-magnesium-lithium material. Background technique: [0002] Lithium-ion batteries have the advantages of high energy density, long service life, no memory effect and no heavy metals such as cadmium and lead. Lithium-ion batteries have been widely used in portable devices such as mobile phones, notebook computers, and cameras. In the application of small power batteries such as electric tools and electric bicycles, lithium-ion batteries can also replace the current Cd-Ni batteries and lead-acid batteries that have an impact on the environment. As early as 2005, the European Union issued RoHS regulations, which specifically restricted The content of six chemical elements such as Pb, Cr, and Cl in chemicals. This has brought more opportunities for the development of the lithium-ion battery industry. Especially in the...

AI Technical Summary

Problems solved by technology

[0003] The research on lithium ion originated in the 1970s. At that time, it was mainly a rechargeable lithium ion battery. However, the surface of the negative metal lithium was uneven, which would lead to uneven surface potential. Lithium dendrites would continue to grow during the charging and discharging process. Large, on the one hand, it may be broken, causing irreversible loss of lithium; on the other hand, lithium dendrites may pierce the separator and cause a short circuit inside the battery, and the instantaneous large current will cause thermal runaway, causing the battery to catch fire or even explode. There are potential safety hazards, and its cycle performance cannot meet the requirements. Therefore, this battery remains in the experimental stage and has not been truly commercialized.

[0004] In recent years, lithium-ion batteries have developed rapidly. At present, the precursors of power lithium-ion batteries mainly include tricobalt tetroxide, manganese trioxide, iron hydroxyphosphate, cobalt nickel oxide, nickel oxycobalt manganese, cobalt magnesium manganese carbonyl, magnesium-doped cobalt trioxide, etc., but The lithium-ion battery material prepared by it has poor safety, unstable electrochemical performance, and short service life, which requires surface coating of the positive electrode material prepared by it.