Modification method of high-voltage olivine-type lithium cobalt phosphate positive electrode material

The invention provides a preparation method of N, F co-doped carbon layer modified lithium cobalt phosphate. The preparation method mainly comprises the following steps: pre-sintering a Li source, a Co source and a P source in a tubular furnace to obtain a lithium cobalt phosphate precursor; and mixing the precursor with a carbon source containing N and F elements, and sintering to obtain the N and F co-doped carbon layer modified lithium cobalt phosphate positive electrode material. In the lithium cobalt phosphate positive electrode material, the N and F co-doped carbon layer uniformly coats the surface of the lithium cobalt phosphate positive electrode material to form a Co-N-C chemical bond, so that the electronic conductivity, the cycling stability and the rate capability of the lithium cobalt phosphate are remarkably improved. 本发明提供了一种N、F共掺杂碳层改性磷酸钴锂的制备方法。该制备方法主要包括，将Li源、Co源、P源置于管式炉中进行预烧得到磷酸钴锂前驱体；将前驱体与含N、F元素的碳源混合后烧结，得到N、F共掺杂碳层改性磷酸钴锂正极材料。此发明中，N、F共掺杂碳层均匀地包覆在磷酸钴锂正极材料表面，并形成Co-N-C化学键，此方案显著提高了磷酸钴锂的电子导电性、循环稳定性和倍率