Nickel hydrogen secondary battery

Patent metadata

Field	Value
Publication number	US-2017110764-A1
Application number	US-201515317106-A
Country	US
Kind code	A1
Filing date	Jun 23, 2015
Priority date	Jun 27, 2014
Publication date	Apr 20, 2017
Grant date	—

Abstract

A nickel hydrogen secondary battery accommodates an electrode group including a positive electrode and a negative electrode which are stacked one on top of another through a separator, together with an alkaline electrolyte. The battery contains Li, with a total amount of Li in the battery 2 of 15 to 50 mg/Ah, as determined as the mass in terms of LiOH per Ah of the positive electrode capacity. The negative electrode includes particles of rare earth-Mg—Ni-based hydrogen storage alloy which contains a rare earth element, Mg and Ni. The hydrogen storage alloy particles 44 includes, on the surface thereof, a rare earth hydroxide which is the hydroxide of a rare earth element and has a specific surface area of 0.1 to 0.5 m 2 /g.

First claim

1 . A nickel hydrogen secondary battery comprising an electrode group hermetically enclosed in a container together with an alkaline electrolyte, the electrode group including a positive electrode and a negative electrode which are stacked one on top of another through a separator, wherein
the nickel hydrogen secondary battery contains Li, with a total amount of Li in the nickel hydrogen secondary battery of 15 to 50 mg/Ah, as determined as the mass in terms of LiOH per Ah of the positive electrode capacity, the negative electrode includes particles of a rare earth-Mg—Ni-based hydrogen storage alloy which contains a rare earth element, Mg and Ni, and the particles of the hydrogen storage alloy include, on the surface thereof, a rare earth hydroxide which is a hydroxide of the rare earth element, and have a specific surface area of 0.1 to 0.5 m 2 /g.

2 . The nickel hydrogen secondary battery according to claim 1 , wherein the hydrogen storage alloy has a composition represented by a general formula: Ln 1-x Mg x (Ni 1-y T y ) z , wherein Ln represents at least one element selected from La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ca, Sr, Sc, Y, Ti, Zr and Hf; T represents at least one element selected from Mn, Co, V, Nb, Ta, Cr, Mo, Fe, Al, Ga, Zn, Sn, In, Cu, Si, P and B; and the subscripts x, y and z satisfy relations 0<x≦1, 0≦y≦0.5, and 2.5≦z≦4.5, respectively.

3 . The nickel hydrogen secondary battery according to claim 1 , wherein the hydrogen storage alloy has a composition configured to exclude Mn and Co.

4 . The nickel hydrogen secondary battery according to claim 1 , wherein a La content ratio of the rare earth element components of the hydrogen storage alloy is 20 mass % or more.

5 . The nickel hydrogen secondary battery according to claim 1 , wherein a Sm content ratio of the rare earth element components of the hydrogen storage alloy is 20 mass % or more.

6 . The nickel hydrogen secondary battery according to claim 1 , wherein
the positive electrode comprises positive electrode active material particles, wherein the positive electrode active material particles comprise base particles composed mainly of nickel hydroxide and a conductive layer comprising a Li-containing Co compound and covering the surface of the base particles.

7 . The nickel hydrogen secondary battery according to claim 1 , wherein the positive electrode comprises at least one selected from the group consisting of a Y compound, a Nb compound, an Yb compound, and a W compound, as an additive.

8 . The nickel hydrogen secondary battery according to claim 1 , wherein the alkaline electrolyte comprises LiOH.

9 . The nickel hydrogen secondary battery according to claim 1 , wherein the rare earth hydroxide are needle crystals deposited on the surface of the hydrogen storage alloy particles.

Assignees

• Fdk Corp

Inventors

• Kihara Masaru
• Saguchi Akira
• Shingai Yusuke
• Ishida Jun
• Kai Takuya

Classifications

• H01M10/26

  Selection of materials as electrolytes · CPC title

• H01M4/52

  of nickel, cobalt or iron · CPC title

• H01M4/383

  Hydrogen absorbing alloys · CPC title

• H01M4/46

  Alloys based on magnesium or aluminium · CPC title

• H01M10/30 Primary

  Nickel accumulators (H01M10/34 takes precedence) · CPC title