Nickel hydrogen battery

Patent metadata

Field	Value
Publication number	US-9985288-B2
Application number	US-201615235615-A
Country	US
Kind code	B2
Filing date	Aug 12, 2016
Priority date	Aug 21, 2015
Publication date	May 29, 2018
Grant date	May 29, 2018

Abstract

A nickel hydrogen battery configured to suppress a decrease in battery voltage. The battery comprises a cathode containing a cathode active material, an anode containing an anode active material, and an electrolyte layer in contact with the cathode and the anode. The cathode active material contains H 2 NiP 2 O 7 having a crystal structure including at least one NiO 6 octahedron and at least one PO 4 tetrahedron.

First claim

What is claimed is:

1. A nickel hydrogen battery comprising:
a cathode including a cathode active material;
an anode including an anode active material; and
an electrolyte layer in contact with the cathode and the anode,
wherein the cathode active material includes H 2 NiP 2 O 7 having a crystal structure comprising at least one NiO 6 octahedron and at least one PO 4 tetrahedron.

2. The nickel hydrogen battery according to claim 1 , wherein the crystal structure comprises a plurality of the NiO 6 octahedra, and
the NiO 6 octahedra share edges with the NiO 6 octahedra adjacent thereto.

3. The nickel hydrogen battery according to claim 1 , wherein the crystal structure comprises a plurality of the PO 4 tetrahedra, and
the PO 4 tetrahedra share apices with the PO 4 tetrahedra adjacent thereto.

4. The nickel hydrogen battery according to claim 1 , wherein the H 2 NiP 2 O 7 has a three-dimensional framework formed by sharing oxygen atoms included in the at least one NiO 6 octahedron and the at least one PO 4 tetrahedron.

5. The nickel hydrogen battery according to claim 1 , wherein the crystal structure belongs to space group P2 1 /c determined by X-ray diffraction measurement.

6. The nickel hydrogen battery according to claim 1 , wherein the anode active material includes at least one selected from hydrogen and a hydrogen storage alloy.

7. The nickel hydrogen battery according to claim 1 , wherein a ratio of the portion of the crystal structure of the H 2 NiP 2 O 7 comprising the at least one NiO 6 octahedron and the at least one PO 4 tetrahedron is 70 mass % or more.

8. The nickel hydrogen battery according to claim 1 , wherein a content ratio of the H 2 NiP 2 O 7 in the cathode active material is in the range of 60% to 100%, by mass %, with respect to the total mass of the cathode active material.

9. The nickel hydrogen battery according to claim 1 , wherein the cathode active material has diffraction peaks at the following positions of diffraction angle 2θ: 12.44°, 21.35°, 26.05°, 27.84° and 32.53°, with a margin of error of about 0.50°.

10. The nickel hydrogen battery according to claim 1 , further comprising an outer case configured to house the cathode, the anode and the electrolyte layer.

Assignees

• Toyota Motor Co Ltd

Inventors

• Nakayama Hideki

Classifications

• H01M2004/028

  Positive electrodes · CPC title

• H01M4/242

  Hydrogen storage electrodes · CPC title

• C01B25/42

  Pyrophosphates · CPC title

• H01M4/5825 Primary

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

• H01M10/345 Primary

  Gastight metal hydride accumulators · CPC title