Preparation method of thulium-doped lithium titanate positive electrode material for lithium-ion battery

Abstract

The invention discloses a preparation method of a thulium-doped lithium titanate positive electrode material for a lithium-ion battery. The preparation method comprises the steps of (a) carrying out weighing, (b) adding absolute ethyl alcohol to a raw material, carrying out ball-milling and taking out the raw material for drying; (c) adding an acetate fiber, a mixed molten salt of potassium chloride and sodium chloride and the absolute ethyl alcohol to the raw material prepared in the step (b), and carrying out ball-milling and drying; and (d) carrying out sintering at 750-800 DEG C for 4-6 hours, cooling after sintering is completed, cleaning a product with water and drying the product to obtain the thulium-doped lithium titanate positive electrode material. The thulium-doped lithium titanate positive electrode material for the lithium-ion battery disclosed by the invention has higher discharge capacity and gram volume; the thulium-doped lithium titanate positive electrode material is of a hollow tubular structure and the tube wall is of a loose structure; and the problem of volume expansion in the charge-discharge process can be relieved. By the preparation method, an inorganic filler titanium dioxide in the acetate fiber is utilized and is doped into crystal lattices of the lithium titanate positive electrode material; the stability of the lithium titanate positive electrode material is improved; and the capacity fading problem of the lithium-ion battery is improved.

Description

technical field [0001] The invention relates to the technical field of lithium ion battery manufacturing, in particular to a preparation method of a thulium-doped lithium titanate cathode material for lithium ion batteries. Background technique [0002] Compared with other types of batteries such as lead-acid and nickel-cadmium, lithium-ion batteries have the advantages of large specific capacity, high working voltage, fast charging speed, wide working temperature range, long cycle life, small size, light weight, green and pollution-free, etc. At present, it has been widely used in mobile phones, notebook computers, electric tools and other fields, and its application scope is becoming more and more extensive. The rapid development of new digital electronic products has put forward more and more demands on the energy density and high reliability of lithium-ion batteries. high demands. [0003] Like other secondary batteries, the positive electrode material also occupies a v...

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Problems solved by technology

[0003] Like other secondary batteries, the positive electrode material also occupies a very high position in the lithium-ion battery. Together with the negative electrode material, it determines the performance of the lithium-ion battery. Traditional lithium-ion batteries often use lithium cobalt oxide, lithium manganese oxide, and lithium nickel oxide. Or lithium-containing materials such as nickel-cobalt lithium manganese oxide are used as positive electrode materials for lithium-ion batteries. Recently, lithium iron phosphate materials have increasingly become the focus of attention, but these lithium-ion battery positive electrode materials still have some defects, such as discharge capacity. It can be objectively improved, but the gram capacity is still small, which greatly limits the growth of the finished product capacity of lithium-ion batteries, and also limits the development of lithium-ion batteries to miniaturization and miniaturization; limits the development of lithium-ion powered vehicles, and in the future Under the premise of increasing the self-weight of electric vehicles, the mileage of electric vehicles increases slowly, or even difficult to increase; it also limits the endurance of mobile devices such as mobile phones. The battery puts forward higher requirements. When it needs to meet the requirements of smaller size and larger capacity, it is difficult for the existing lithium-ion batteries to meet similar requirements.