# US 2014/0193722 A1 · Metal hydride alloy with improved low-temperature performance

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- Number: US 2014/0193722 A1
- Document ID: US20140193722A1
- Status: Published application
- Kind: A1
- Application number: 13/735,282
- Filed: 2013-01-07
- Published: 2014-07-10
- Earliest claimed: 2013-01-07
- Assignees: Ovonic Battery Company, Inc.
- Applicants: Ovonic Battery Company, Inc.
- Inventors: Kwo Young; Benjamin Reichman; Michael A. Fetcenko
- Web page: https://patentgrep.com/patent/US20140193722A1

## CPC

- H01M 4/383: {Hydrogen absorbing alloys}
- H01M 4/385: {of the type LaNi5}
- H01M 10/345: {Gastight metal hydride accumulators}
- Y02E 60/10: Energy storage using batteries
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

The performance of an ABx type metal hydride alloy is improved by adding an element to the alloy which element is operative to enhance the surface area morphology of the alloy. The alloy may include surface regions of differing morphologies.

## Claims

### Claim 1

A method for improving the low-temperature electrochemical performance of an ABx (1≦x≦5) type metal hydride alloy incorporated into a rechargeable battery cell, said method comprising:
adding an element selected from the group consisting of: Si, Mo, Y, Sn, Sb, and combinations thereof to said alloy which element is operative to increase the surface area of said alloy by a factor of more than 2 and/or the catalytic ability of said alloy by more than 20%.

### Claim 2 (depends on 1)

The method of claim 1, wherein said element increases the surface area of said alloy by a factor of at least 4.

### Claim 3 (depends on 1)

The method of claim 1, wherein said element increases both the surface area and the catalytic activity of said alloy.

### Claim 4 (depends on 1)

The method of claim 1, wherein said element comprises Si.

### Claim 5 (depends on 1)

The method of claim 1, wherein said alloy is selected from the group consisting of: AB alloys, AB2 alloys, AB3 alloys, AB5 alloys, A2B7 alloys, and combinations thereof.

### Claim 6 (depends on 1)

The method of claim 1, wherein said alloy is an AB2 Laves phase alloy.

### Claim 7 (depends on 1)

The method of claim 1, wherein said metal hydride alloy includes nickel and said element substitutes for a portion of the nickel in said nickel metal hydride alloy.

### Claim 8 (depends on 1)

The method of claim 1, wherein said element is present in an amount greater than zero and ranging up to 10 atomic percent.

### Claim 9 (depends on 1)

The method of claim 1, wherein said element is present in an amount of up to 5 atomic percent.

### Claim 10

A rechargeable electrochemical cell having a nickel cathode, a separator, electrolyte, and an anode, said anode comprising an ABx (1 <x<5) type metal hydride alloy material, said cell characterized by improved low temperature electrochemical performance, the improvement comprising:
the addition of an element to said alloy, said element (i) operative to increase the surface area and/or catalytic ability of said alloy and (ii) selected from the group consisting of: Si, Mo, Y, Sn, Sb, and combinations thereof and wherein said element increases the surface area of said alloy by a factor of more than 2 and/or the catalytic activity of said alloy by more than 20% (as compared to the surface area and/or catalytic activity of said alloy without the addition of said element).

### Claim 11 (depends on 10)

The cell of claim 10, wherein said element increases the surface area of said alloy by a factor of at least 4.

### Claim 12 (depends on 10)

The cell of claim 10, wherein said element increases both the surface area and the catalytic activity of said alloy.

### Claim 13 (depends on 10)

The cell of claim 10, wherein said element comprises Si.

### Claim 14 (depends on 10)

The cell of claim 10, wherein said alloy is selected from the group consisting of: AB alloys, AB2 alloys, AB3 alloys, AB5 alloys, A2B7 alloys, and combinations thereof.

### Claim 15 (depends on 10)

The cell of claim 10, wherein said alloy is an AB2 Laves phase alloy.

### Claim 16 (depends on 10)

The cell of claim 10, wherein said metal hydride alloy includes nickel and the element substitutes for a portion of the nickel in said alloy.

### Claim 17 (depends on 10)

The cell of claim 10, wherein said element is present in an amount greater than zero and up to 10 atomic percent.

### Claim 18 (depends on 10)

The cell of claim 10, wherein said element is present in an amount greater than zero and up to 5 atomic percent.

### Claim 19 (depends on 15)

The cell of claim 15, wherein said alloy comprises: Ti, Zr, V, Cr, Mn, Co, Ni, Si, Sn, and Al.

### Claim 20 (depends on 19)

The cell of claim 19, wherein said alloy comprises on an atomic percentage basis: Ti12Zr21.5V10Cr7.5Mn8.1Co8.0Ni32.2-xSixSn0.3Al0.4 wherein x is greater than 0 and less than or equal to 4.

### Claim 21

A method for making a composite ABx (1≦x≦5) type metal hydride material, said material comprising a first, matrix portion and a plurality of second, channel portions disposed in spaced apart relationship in said matrix portion, said channel portions having a concentration of catalytic channels defined therein, said channels having a cross-sectional dimension in the range of 25-150 angstroms, and a length which is greater than the cross-sectional dimension of said channels, said channels having catalytic sites defined thereupon, said method comprising the steps of:
providing a first, ABx matrix material;
providing a second, ABx metal hydride material, said second material including an additive element selected from the group consisting of Si, Mo, Y, Sn, Sb, and combinations thereof, said element being operative to increase the electrochemically active surface area of said second material by a factor of more than 2 and/or the catalytic ability of said second material by more than 20%;
activating said second material; and
dispersing said second material in said first material so as to provide said composite material.

### Claim 22 (depends on 21)

The method of claim 21, wherein the step of dispersing said second material in said first material is carried out after the step of activating said second material.

### Claim 23 (depends on 21)

The method of claim 21, wherein said step of dispersing said second material is carried out before the step of activating said second material.

### Claim 24 (depends on 21)

The method of claim 21, wherein said step of dispersing said second material is carried out by preferential corrosion of metals present in the hydride material.

### Claim 25 (depends on 21)

The method of claim 21, wherein the first material has a melting point which is less than the melting point of said second material, and the step of dispersing said second material in said first material comprises dispersing particles of said first material in a molten body of said second material.