APPROACH FOR MANUFACTURING EFFICIENT MESOPOROUS NANO-COMPOSITE POSITIVE ELECTRODE LiMn1-XFeXPO4 MATERIALS

Abstract

A mesoporous nano-composite LiMn 1-x Fe x PO 4 (0≦x≦1) particle that has a uniform carbon coating on the surface of the particle. Also disclosed is a mesoporous nano-composite LiMn 1-x Fe x PO 4 particle prepared by a process including steps: (i) providing a mixture of a soft-template compound, a lithium ion-containing compound, an iron ion-containing compound, a manganese ion-containing compound, and a phosphate ion-containing compound in a solvent; (2) removing the solvent to obtain a LiMn 1-x Fe x PO 4 precursor; and (3) calcining the precursor followed by milling and annealing to obtain the LiMn 1-x Fe x PO 4 particle.

1 . A mesoporous nano-composite particle, comprising:
 phospho-olivine LiMn 1-x Fe x PO 4  crystals forming a grain, in which 0≦x≦1, and   a uniform carbon coating on the surface of the grain, the coating having an average thickness of 1 to 10 nm,   wherein the particle has a particle size of 10 to 100 nm, a surface area of 30 to 50 m 2 g −1 , and a pore size of 3 to 40 nm.   
     
     
         2 . The particle of  claim 1 , wherein the particle has a particle size of 50 to 80 nm, a surface area of 40 to 50 m 2 g 1 , and a pore size of 3 to 30 nm, and the carbon coating has an average thickness of 3 to 7 nm. 
     
     
         3 . The particle of  claim 1 , wherein the carbon coating is formed of conductive carbon selected from the group consisting of acetylene black, conductive carbon black, carbon nanotubes, and graphitic nano-sheets. 
     
     
         4 . The particle of  claim 3 , wherein the conductive carbon is conductive carbon black selected from the group consisting of Printex XE2, Black Pearls 2000, and Ketjenblack. 
     
     
         5 . The particle of  claim 2 , wherein the carbon coating is formed of conductive carbon selected from the group consisting of acetylene black, conductive carbon black, carbon nanotubes, and graphitic nano-sheets. 
     
     
         6 . The particle of  claim 5 , wherein the conductive carbon is conductive carbon black selected from the group consisting of Printex XE2, Black Pearls 2000, and Ketjenblack. 
     
     
         7 . The particle of  claim 1 , wherein x is 0, 0.2, 0.5, or 0.8. 
     
     
         8 . The particle of  claim 7 , wherein the particle has a particle size of 50 to 80 nm, a surface area of 40 to 50 m 2 g −1 , and a pore size of 3 to 30 nm, and the carbon coating has an average thickness of 3 to 7 nm. 
     
     
         9 . The particle of  claim 7 , wherein the carbon coating is formed of conductive carbon selected from the group consisting of acetylene black, conductive carbon black, carbon nanotubes, and graphitic nano-sheets. 
     
     
         10 . The particle of  claim 1 , wherein 0<x<1. 
     
     
         11 . The particle of  claim 10 , wherein the particle has a particle size of 50 to 80 nm, a surface area of 40 to 50 m 2 g −1 , and a pore size of 3 to 30 nm, and the carbon coating has an average thickness of 3 to 7 nm. 
     
     
         12 . The particle of  claim 10 , wherein the carbon coating is formed of conductive carbon selected from the group consisting of acetylene black, conductive carbon black, carbon nanotubes, and graphitic nano-sheets. 
     
     
         13 . The particle of  claim 12 , wherein the conductive carbon is conductive carbon black selected from the group consisting of Printex XE2, Black Pearls 2000, and Ketjenblack. 
     
     
         14 . The particle of  claim 11 , wherein the carbon coating is formed of conductive carbon selected from the group consisting of acetylene black, conductive carbon black, carbon nanotubes, and graphitic nano-sheets. 
     
     
         15 . The particle of  claim 14 , wherein the conductive carbon is conductive carbon black selected from the group consisting of Printex XE2, Black Pearls 2000, and Ketjenblack. 
     
     
         16 . The particle of  claim 10 , wherein x is 0.2, 0.5, or 0.8. 
     
     
         17 . The particle of  claim 16 , wherein the particle has a particle size of 50 to 80 nm, a surface area of 40 to 50 m 2 g −1 , and a pore size of 3 to 30 nm, and the carbon coating has an average thickness of 3 to 7 nm. 
     
     
         18 . The particle of  claim 16 , wherein the carbon coating is formed of conductive carbon selected from the group consisting of acetylene black, conductive carbon black, carbon nanotubes, and graphitic nano-sheets. 
     
     
         19 . The particle of  claim 18 , wherein the conductive carbon is conductive carbon black selected from the group consisting of Printex XE2, Black Pearls 2000, and Ketjenblack. 
     
     
         20 . A mesoporous nano-composite LiMn 1-x Fe x PO 4 particle, wherein the particle is prepared by a process including the following steps:
 providing a solvent containing a soft-template compound, a lithium ion-containing compound, an iron ion-containing compound, a manganese ion-containing compound, and a phosphate ion-containing compound;   removing the solvent to obtain a LiMn 1-x Fe x PO 4  precursor;   calcining the LiMn 1-x Fe x PO 4  precursor to obtain crystalline LiMn 1-x Fe x PO 4  grains;   milling the crystalline LiMn 1-x Fe x PO 4  grains in the presence of conductive carbon to obtain nanostructured LiMn 1-x Fe x PO 4 /C particles; and   annealing the nanostructured LiMn 1-x Fe x PO 4 /C particles to obtain nano-composite LiMn 1-x Fe x PO 4 /C particles,   
       wherein the amounts of the lithium ion-containing compound, the ferrous ion-containing compound, the manganese ion-containing compound, and the phosphate ion-containing compound are in stoichiometric proportion; and the weight ratio of the soft-template compound to the lithium ion-containing compound is 1:1 to 10:1.