The present disclosure belongs to technical field of cathode materials of lithium batteries, and discloses a preparation method of high-safety high-capacity lithium manganese iron phosphate. The method includes the steps: (1) synthesizing a ferrous phosphate precursor through a co-precipitation process, and sintering to obtain an anhydrous ferrous phosphate precursor; (2) synthesizing a manganese phosphate precursor through co-precipitation process, and sintering to obtain an anhydrous manganese phosphate precursor; (3) adding lithium phosphate and deionized water into anhydrous ferrous phosphate precursor, and performing ball milling and wet sanding to obtain slurry A; (4) adding lithium phosphate, an organic carbon source, a dispersant, a dopant and deionized water into anhydrous manganese phosphate precursor, and performing ball milling and wet sanding to obtain slurry B; and (5) mixing slurry A with slurry B, and performing ball milling, spray drying, sintering and air jet pulverization to obtain high-safety high-capacity lithium manganese iron phosphate.

Provided are a phosphate material with a nanoporous structure, a preparation method therefor and a use thereof. It has a chemical formula of Mn.sub.1-xFe.sub.xPO.sub.4, (0.01x0.99) and has a particle size of at most 50 nm and a porous structure. Also provided is a phosphate material having a general chemical formula of Mn.sub.1-a-bFe.sub.aM.sub.bPO.sub.4, wherein M is one or more selected from the group consisting of Mg, Ti, V, Cr, Co, Ni, Zn, Ga, Al, Zr, Nb, Mo, Sn, Sb, Ca, Ba, Sr, B, Ru, Si, Te, Nb, Cu and Li, and preferably a combination of five or more of the elements, 0.01a0.98, 10.sup.4b10.sup.2, and the phosphate material has a particle size of at least 50 nm and has a porous structure. The material can be used for preparing a manganese iron phosphate battery cathode material, and the specific capacity, rate performance and cycle performance of the obtained anode material are improved.

The present invention relates to hollow nanocoils having a three-dimensional helical structure in the form of a hollow tube and a method of manufacturing the same. The present invention provides a method of synthesizing metal nanocoils into inorganic hollow nanocoils using the galvanic replacement reaction and an electrochemical reaction including the Kirkendall effect. The inorganic hollow nanocoil structure body of the present invention can be applied to various fields such as sensors, catalysts, batteries, or gene delivery and therapy using a large surface area.

Positive electrode active materials, their manufacturing methods, and rechargeable lithium batteries including the same are provided. The positive electrode active material comprises a first particle that comprises a plurality of primary particles and a first coating part on an interface between the primary particles. The primary particles comprise a compound represented by Chemical Formula 1.

The first coating part comprises lithium metal phosphate.

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In Chemical Formula 1, the subscripts satisfy the relationship of 0.8<a11.2, 0.7x11.0, 0y10.3, 0z10.05, 0c10.05, and 0.99x1+y1+z11.01, and B.sup.1 is at least one element selected from among Ti, Mg, V, and Nb.