Preparation method of calcium hexaluminate composite coating material with high adhesive force, high-temperature reduction resistance and alkali attack resistance

Abstract

The invention discloses a preparation method of a calcium hexaluminate composite coating material with high adhesive force, high-temperature reduction resistance and alkali attack resistance. The preparation method includes the steps of preparation of coating powder, synthesis of coating powder, processing and compounding of coating powder, preparation of coating slurry, preparation of the coating, sintering of the coating material, and the like. The calcium hexaluminate composite coating material prepared by the method has high melting temperature which can be up to 1875 DEG C, has good stability in high-temperature reduction resistance, has high alkali attack resistance capacity in an alkali environment; besides, the calcium hexaluminate composite coating material has a lamellar structure which can absorb volume expansion effect caused by high temperature to reduce expansion coefficient of a crucible, is not easy to crack and come off, and can effectively prevent impurity from beingmixed to a lithium ion battery positive electrode materials during use.

Description

technical field [0001] The invention relates to the technical field of preparation technology of refractory materials, in particular to a preparation method of a composite calcium hexaaluminate coating material with high adhesion, high temperature reduction resistance and alkali corrosion resistance. Background technique [0002] With the continuous development of industries such as new energy and environmental protection engineering, the requirements for the research and manufacture of related auxiliary equipment and materials are also increasing. In recent years, the preparation of cathode materials for lithium batteries has attracted more and more attention from all parties. The cathode materials of lithium batteries mainly include lithium cobaltate, lithium manganese oxide, nickel-manganese-cobalt ternary materials, and lithium iron phosphate. The uniformity of these cathode materials Indexes such as purity and purity restrict the performance of the material. The impurit...

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Problems solved by technology

The preparation of cathode materials for lithium batteries is generally synthesized from basic raw materials through high-temperature solid-state reaction. The reactor is made of refractory materials with special properties. Currently, crucibles such as cordierite, mullite, and corundum are commonly used. However, due to Lithium-containing cathode materials are strongly alkaline and highly corrosive, which directly causes cordieri to be easily corroded, and the quality of cathode materials is degraded due to the mixing of harmful impurities in the crucible; mullite has high silicon content and poor alkali resistance , long-term use will inevitably cause the exfoliation produced on the inner wall of the crucible to be mixed into the positive electrode material and reduce the performance of the product; the thermal expansion coefficient of the alumina crucible is large, and the crucible is prone to cracking during use, which will affect the service life and increase the production cost of the manufacturer.

These problems have always limited the development of the industry

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