Method for preparing vapor-phase coated modified lithium nickelate, cobaltate and manganate positive electrode materials

Abstract

The invention discloses a method for preparing vapor-phase coated modified lithium nickelate, cobaltate and manganate positive electrode materials. The method includes steps of S1, heating anhydrous acetic acid liquid until the anhydrous acetic acid liquid is boiling at the temperature of 120 DEG C, delivering acetic acid steam to gas inlets of pulse type gas flow mixing machines via pipelines andkeeping gas inlet pressures higher than or equal to 0.8 Mpa; S2, feeding conventional lithium nickelate, cobaltate and manganate positive electrode materials into bins of pneumatic mixing machines and allowing the conventional lithium nickelate, cobaltate and manganate positive electrode materials to move at the high speeds under the effects of acetic acid vapor so as to obtain coated lithium nickelate, cobaltate and manganate materials; S3, heating the coated lithium nickelate, cobaltate and manganate materials obtained at the step S2 until the temperatures of the lithium nickelate, cobaltate and manganate materials reach 650-800 DEG C and preserving heat for 8-12 h; S4, naturally cooling sintered products obtained at the step S3 until the temperatures of the sintered products reach theroom temperature and smashing and sieving the sintered products to obtain the vapor-phase coated modified lithium nickelate, cobaltate and manganate positive electrode materials which are target products. The method has the advantages that the PH (potential of hydrogen) values of lithium nickelate, cobaltate and manganate surfaces can be lowered to a great extent by the aid of material surface alkaline and acidic vapor neutralization principles, accordingly, the cycle performance and the processing properties of the lithium nickelate, cobaltate and manganate materials can be improved, and theinput cost of high-nickel ternary materials used by battery enterprises can be reduced to a great extent.

Description

technical field [0001] The invention relates to a preparation method of vapor-phase coated modified nickel-cobalt lithium manganese oxide cathode material. Background technique [0002] At present, lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, nickel cobalt lithium manganese oxide, etc. are used in the market as anode materials for lithium-ion batteries. Due to its high compaction density, lithium cobalt oxide once became the overlord in the 3C field, but Due to the scarcity of cobalt resources, the cost is very expensive. The cost of lithium manganese oxide is relatively low, but its energy density is low and its high-temperature performance is poor. Currently, it is mainly used in low-end digital products. Although lithium iron phosphate has excellent cycle performance, its low The specific capacity also begins to limit its development. Nickel-cobalt lithium manganese oxide has high specific capacity and good cycle performance, and is considered t...

AI Technical Summary

Problems solved by technology

However, due to its high nickel content and high pH value, high-nickel ternary materials require battery manufacturers to meet harsh conditions in the manufacturing process, resulting in domestic battery companies being unable to use them or failing to achieve the expected performance after use, which also makes high-nickel ternary materials Sanyuan is not widely used and promoted in China

[0003] At present, in order to reduce the pH value of nickel-cobalt-lithium manganese oxide materials, the surface pH value is generally reduced by washing or wet-coating elements such as aluminum, magnesium, and titanium, but the process is complicated and the cost is high. Although the pH value can be reduced after washing, However, its specific surface area increases, and its cycle performance and specific capacity will also be greatly reduced. Although the coating of aluminum, magnesium, titanium and other elements can also reduce its pH value, the effect is limited, and the processing performance of nickel cobalt lithium manganate is also limited. to significantly improve

Images