Positive electrode material for sodium batteries and method for producing same

Patent metadata

Field	Value
Publication number	US-9537146-B2
Application number	US-201314405830-A
Country	US
Kind code	B2
Filing date	May 10, 2013
Priority date	Jun 12, 2012
Publication date	Jan 3, 2017
Grant date	Jan 3, 2017

Abstract

The invention is to provide a positive electrode material for sodium batteries, which has high operating potential and enable charging and discharging at high potential, and a method for producing thereof. Disclosed is a positive electrode material for sodium batteries, comprising positive electrode active material particles represented by the following general formula (1), and an electroconductive carbonaceous material that coats at least part of the surface of the positive electrode active material particles: General Formula (1): Na x M y (AO 4 ) z (P 2 O 7 ) w wherein M is at least one selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn; A is at least one selected from the group consisting of Al, Si, P, S, Ti, V and W; x is a value that satisfies 4≧x≧2; y is a value that satisfies 4≧y≧1; z is a value that satisfies 4≧x≧0; w is a value that satisfies 1≧w≧0; and at least one of z and w is 1 or more.

First claim

The invention claimed is:

1. A positive electrode material for sodium batteries, comprising positive electrode active material particles having a crystal structure attributed to space group Pn2 1 a and being represented by the following general formula (1), and an electroconductive carbonaceous material that coats at least part of the surface of the positive electrode active material particles:
Na 4 M 3 (PO 4 ) 2 (P 2 O 7 )  General Formula (1):

wherein M is at least one selected from the group consisting of Mn, Co, and Ni.

2. The positive electrode material for sodium batteries according to claim 1 , wherein the M in the general formula (1) is divalent before charging.

3. The positive electrode material for sodium batteries according to claim 1 , wherein the positive electrode active material is represented by the general formula Na 4 Mn 3 (PO 4 ) 2 (P 2 O 7 ).

4. A method for producing a positive electrode material for sodium batteries, the material comprising positive electrode active material particles having a crystal structure attributed to space group Pn2 1 a and being represented by the following general formula (1), and an electroconductive carbonaceous material that coats at least part of the surface of the positive electrode active material particles:
Na 4 M 3 (PO 4 ) 2 (P 2 O 7 )  General Formula (1):

wherein M is at least one selected from the group consisting of Mn, Co, and Ni,
the method comprising the steps of:
preparing a complex containing the positive electrode active material particles and the electroconductive carbonaceous material adhering through a pressing process to the surface of the positive electrode active material particles, by pressing and allowing the electroconductive carbonaceous material to adhere to the surface of the particles by mechanochemical treatment, and
heat-treating the complex under an inert atmosphere or reduction atmosphere.

5. The method for producing a positive electrode material for sodium batteries according to claim 4 , wherein the M is divalent before charging.

6. The method for producing a positive electrode material for sodium batteries according to claim 4 , wherein the positive electrode active material is represented by the general formula Na 4 Mn 3 (PO 4 ) 2 (P 2 O 7 ).

Assignees

• Toyota Motor Co Ltd

Inventors

• Nose Masafumi

Classifications

• 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

• H01M4/366 Primary

  as layered products · CPC title

• H01M4/485

  of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence) · CPC title

• H01M2004/028

  Positive electrodes · CPC title

• Y02P70/54

  Cross-Sectional Technologies · mapped topic