Biosynthesis method of high-performance olivine type manganese-based phosphate positive electrode material

Abstract

The invention provides a biosynthesis method of a high-performance olivine-type manganese-based phosphate positive electrode material, and an olivine-type phosphate material is synthesized by using a biomineralization mechanism of yeast cells and is used as an electrode material of a lithium ion battery. According to the biosynthesis method disclosed by the invention, the size, the structure, the morphology, the chemical composition, the crystal growth orientation and the like of nano inorganic salt particles can be more effectively regulated and controlled on the molecular level; wherein the mineralization growth process of phosphate crystals is regulated by utilizing a biological mineralization mechanism of yeast cells, and nano crystal LiMn0.8Fe0.2PO4 particles preferentially growing in the Li < + > transmission crystal orientation [010] direction are obtained; furthermore, by virtue of a high-temperature inert atmosphere heat treatment condition, yeast cells are thermally decomposed into a biomass carbon network in which amorphous carbon and nitrogen-doped graphene coexist, and a multi-stage nano in-situ composite structure is formed between the biomass carbon network and LiMn0.8Fe0.2PO4 nanocrystals, so that a three-dimensional conductive network of an efficient electronic path and an ion path is constructed, and the electrochemical performance of the manganese-based olivine type LiMn0.8Fe0.2PO4 positive electrode material is remarkably improved.

Description

technical field [0001] The invention belongs to the technical field of biosynthesis, and in particular relates to a biosynthesis method of a high-performance olivine-type manganese-based phosphate cathode material. Background technique [0002] Olivine-type manganese-based phosphate, because of its advantages of high potential and high specific capacity, is considered to be an important candidate for high-energy-density lithium-ion battery cathode materials. LiMnPO4 has the same olivine structure as LiFePO4 and belongs to the Pnmb space group. Since the redox reaction potential of Mn2+ / Mn3+ in LiMnPO4 (4.1V vs. Li / Li+) is 0.7V higher than the redox reaction potential of Fe2+ / Fe3+ in LiFePO4 (3.4V vs. Li / Li+), the LiMnPO4 material can be compared with LiFePO4 The material yields about 20% more energy. However, LiMnPO4 has lower electronic conductivity and ionic conductivity than LiFePO4, and Mn3+ is easy to escape from the MnPO4 lattice into the electrolyte in the highly de...

AI Technical Summary

Problems solved by technology

Among them, the disadvantages of the high-temperature solid-phase method are that the particle size is not easy to control, the particle shape is irregular, it is easy to agglomerate in large pieces, and the tap density is low; the disadvantage of the hydrothermal synthesis method is that the synthesis conditions are strictly controlled, the high-pressure operation is dangerous, and the production cost High; the disadvantage of the sol-gel method is that the synthesis period is long, the energy consumption is large, and the consistency of the gel state is not easy to control; the disadvantage of the spray drying synthesis method is that the equipment is complex, the energy consumption is large, and the product yield is low.

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