Method for producing lithium metal phosphate

Patent metadata

Field	Value
Publication number	US-9590246-B2
Application number	US-201113820388-A
Country	US
Kind code	B2
Filing date	Sep 2, 2011
Priority date	Sep 3, 2010
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

Provided is a method for producing a lithium metal phosphate, and the method comprises initiating and allowing to proceed, in the presence of a polar solvent, a conversion reaction of a lithium ion (Li + ) source such as lithium hydroxide, a divalent transition metal ion (M 2+ ) source such as a divalent transition metal sulfate, and a phosphate ion (PO 4 3− ) source such as phosphoric acid into a lithium metal phosphate at 150° C. or higher. The conversion reaction is initiated and allowed to proceed by bringing solution A containing one of a lithium ion, a divalent transition metal ion, and a phosphate ion into contact with solution B containing the others of these ions at 150° C. or higher, or by adjusting the pH of solution C that has a pH of lower than 4 and contains a lithium ion, a divalent transition metal ion, and a phosphate ion to 4 or higher.

First claim

The invention claimed is:

1. A method for producing a lithium metal phosphate by a conversion reaction of lithium ion (Li+) source, a divalent transition metal ion (M2+) source, and a phosphate ion (PO43−) source,
the method comprising:
preparing solution C having a pH of lower than 4 and a temperature of less than 150° C., and containing a lithium ion, a divalent transition metal ion, and a phosphate ion,
heating the solution C at 150° C. or higher while the pH is lower than 4,
adding a basic liquid to the solution C at 150° C. or higher for elevating the pH from less than 4 to not less than 4 in the presence of a polar solvent while maintaining the temperature of 150° C. or higher to initiate the conversion reaction, and
subsequently maintaining the temperature of 150° C. or higher and the pH of 4 or higher to continue the conversion reaction.

2. The method for producing a lithium metal phosphate according to claim 1 , wherein
the basic liquid is a liquid having a pH of 9 or higher.

3. The method for producing a lithium metal phosphate according to claim 1 , wherein
the lithium ion source is lithium hydroxide, the divalent transition metal ion source is a divalent transition metal sulfate, and the phosphate ion source is a phosphoric acid.

4. The method for producing a lithium metal phosphate according to claim 1 , wherein
the divalent transition metal ion is at least one selected from a group consisting of an iron ion and a manganese ion.

5. The method for producing a lithium metal phosphate according to claim 1 , wherein
the conversion reaction is carried out under a pressure of 0.5 MPa or higher.

Assignees

• Shirakawa Akihiko
• Kabe Isao
• Tonegawa Akihisa
• Showa Denko Kk

Inventors

• Shirakawa Akihiko
• Kabe Isao
• Tonegawa Akihisa

Classifications

• H01M4/5825 Primary

  Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines · CPC title

• C01B25/45

  containing plural metal, or metal and ammonium · CPC title

• H01M4/58 Primary

  of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title