The invention provides
starch-based hard carbon and a preparation method thereof, a negative
electrode plate, a
sodium ion battery and
electric equipment, and relates to the technical field of
new energy. According to the preparation method disclosed by the invention, hydroxyl and
hydrogen atoms in the
starch are consumed through
organic acid esterification, so that a
molten state is not formed in the subsequent oxidation crosslinking and
carbonization processes, the structure and strength of a
carbon skeleton are improved, and functional groups and doped atoms are more easily introduced; in the oxidation cross-linking process,
oxygen-containing functional groups mainly containing carbonyl are mainly introduced, and the cross-linking degree is enhanced, so that
phosphorus and
nitrogen atoms are better doped in subsequent
carbonization, a better spherical structure is formed, and the subsequent
carbonization yield is further improved. The
starch-based hard carbon material prepared by the method has the advantages that the starch-based hard carbon material is mixed with the
phosphorus source and the
nitrogen source for carbonization, the pore-forming process and the
phosphorus-
nitrogen atom
doping process can be directly completed in the heating process, and open pores are changed into closed pores in the high-temperature and constant-temperature process, so that the prepared starch-based hard carbon material has excellent structure and surface groups and heteroatoms, and the dynamic performance of the starch-based hard carbon material is further optimized.