Nitrogen, phosphorus and oxygen in-situ co-doped porous carbon material as well as preparation method and application thereof

The invention discloses a nitrogen, phosphorus and oxygen in-situ co-doped porous carbon material as well as a preparation method and application thereof. Aiming at the problems of heteroatom co-doping and structure regulation and control of a carbon material, the preparation method comprises the following steps: uniformly mixing a coal or petroleum heavy organic matter, guanidine phosphate urea, phosphoric acid threonine, a metal oxide, solid alkali and a solvent, reacting, carbonizing a product in an inert atmosphere, pickling, filtering and drying to obtain the nitrogen, phosphorus and oxygen in-situ co-doped porous carbon material. A cross-linking-grafting-carbonizing strategy is adopted in the preparation process, the phosphate threonine and the phosphate guanidyl urea can cause defects of a carbon microcrystalline structure in the decomposition process, a large number of micropores are formed, and the rate performance and the cycle performance of the porous carbon material serving as the positive electr