Hydrogen Storage Alloys

Patent metadata

Field	Value
Publication number	US-2016233495-A1
Application number	US-201514619455-A
Country	US
Kind code	A1
Filing date	Feb 11, 2015
Priority date	Feb 11, 2015
Publication date	Aug 11, 2016
Grant date	—

Abstract

Hydrogen storage alloys comprising a) at least one electrochemically active main phase and b) at least one electrochemically active secondary phase; and/or comprising a) at least one main phase, b) a storage secondary phase comprising one or more rare earth elements and c) a catalytic secondary phase, where the abundance of the storage secondary phase is >0.5 wt % and the abundance of the catalytic secondary phase is from about 0.3 to about 15 wt %, based on the alloy; exhibit improved electrochemical properties, for example improved low temperature electrochemical properties.

First claim

1 . A hydrogen storage alloy which exhibits
an high rate dischargeability of ≧93% at the 3 rd cycle, defined as the ratio of discharge capacity measured at 50 mA g −1 to that measured at 4 mA g −1 , measured in a flooded cell configuration against a partially pre-charged Ni(OH) 2 positive electrode with no alkaline pretreatment applied before the half-cell measurement and where each sample electrode is charged at a constant current density of 50 mA g −1 for 10 h and then discharged at a current density of 50 mA g −1 followed by two pulls at 12 and 4 mA/g; and/or a charge transfer resistance (R) at −40° C. for the main phase or main phases of ≦150 Ω·g; and/or a surface catalytic ability at −40° C. for the main phase or main phases of ≦30 seconds; and/or a charge transfer resistance (R) at −40° C. of ≦150 Ω·g.

2 . An alloy according to claim 1 comprising a main phase or main phases and a secondary phase.

3 . An alloy according to claim 1 which exhibits
a charge transfer resistance (R) at −40° C. for the main phase or main phases of ≦60 Ω·g; and/or
a charge transfer resistance (R) at −40° C. of ≦60 Ω·g.

4 . A hydrogen storage alloy according to claim 2 comprising a storage secondary phase.

5 . A hydrogen storage alloy according to claim 2 comprising an electrochemically active storage secondary phase.

6 . An alloy according to claim 1 comprising
i) one or more elements selected from the group consisting of Ti, Zr, Nb and Hf and
ii) one or more elements selected from the group consisting of V, Cr, Mn, Ni, Sn, Al, Co, Cu, Mo, W, Fe, Si and rare earth elements; or
i) one or more elements selected from the group consisting of Ti, Zr, Nb and Hf and
ii) Ni, Cr and one or more elements selected from the group consisting of B, Al, Si, Sn, other transition metals and rare earth elements; or
i) one or more elements selected from the group consisting of Ti, Zr, Nb and Hf and
ii) Ni, Cr and one or more elements selected from the group consisting of V, Mn, Sn, Al, Co, Cu, Mo, W, Fe, Si and rare earth elements.

7 . An alloy according to claim 6 where the atomic ratio of ii) to i) is from about 2.02 to about 2.45.

8 . An alloy according to claim 1 comprising a C14 or C15 main Laves phase or comprising C14 and C15 main Laves phases.

9 . An alloy according to claim 1 comprising C14 and C15 main Laves phases where the C14 phase abundance is from about 70 to about 95 wt % and the C15 phase abundance is from about 2 to about 20 wt %, based on the alloy.

10 . An alloy according to claim 2 comprising a catalytic secondary phase.

11 . An alloy according to claim 2 comprising a catalytic secondary phase which has a TiNi (B2) crystal structure.

12 . An alloy according to claim 2 comprising a catalytic secondary phase which comprises one or more elements selected from the group consisting of Ti, Zr, Nb and Hf and also comprises Ni.

13 . An alloy according to claim 2 comprising a catalytic secondary phase which comprises Ti and Ni or comprises Ti, Zr and Ni.

14 . An alloy according to claim 2 comprising a catalytic secondary phase which comprises from about 13 to about 45 at % Ti.

15 . An alloy according to claim 2 comprising a catalytic secondary phase which comprises from about 5 to about 30 at % Zr.

16 . An alloy according to claim 2 comprising a catalytic secondary phase which comprises from about 38 to about 60 at % Ni.

17 . An alloy according to claim 2 comprising a catalytic secondary phase which comprises from about 42 to about 47 at % Ni, from about 20 to about 29 at % Ti and from about 12 to about 22 at % Zr, where (Ti+Zr) is from about 39 to about 43 at %.

18 . An alloy according to claim 2 comprising a catalytic secondary phase which comprises from about 42 to about 47 at % Ni, from about 20 to about 29 at % Ti and from about 12 to about 22 at % Zr, where (Ti+Zr) is from about 39 to about 43 at % and where the at % of Zr is ≦the at % of Ti.

19 . An alloy according to claim 4 where the storage secondary phase comprises Ni.

20 . An alloy according to claim 4 where the storage secondary phase comprises La and Ni.

21 . An alloy according to claim 4 where the storage secondary phase comprises from about 30 to about 60 at % of one or more rare earth elements.

22 . An alloy according to claim 4 where the storage secondary phase comprises from about 30 to about 60 at % Ni.

23 . An alloy according to claim 4 where the storage secondary phase comprises from about 41 to about 51 at % La and from about 44 to about 50 at % Ni.

24 . An alloy according to claim 4 where the storage secondary phase abundance is from about 0.51 to about 15 wt %, based on the alloy.

25 . An alloy according to claim 2 comprising a catalytic secondary phase with an abundance from about 0.3 to about 15 wt %, based on the alloy.

26 . An alloy according to claim 2 comprising a storage secondary phase and a catalytic secondary phase.

27 . An alloy according to claim 26 comprising from about 0.1 to about 4.0 wt % of a catalytic secondary phase comprising Ti and Ni and from about 0.1 to about 4.0 wt % of a storage secondary phase comprising La and Ni, based on the total alloy.

28 . An alloy according to claim 26 where the weight ratio of the catalytic secondary phase abundance to the storage secondary phase abundance is <5.0.

29 . An alloy according to claim 26 where the weight ratio of the catalytic secondary phase abundance to the storage secondary phase abundance is from about 5 to about 0.1.

30 . An alloy according to claim 26 where the total abundance of the storage and catalytic secondary phases is from about 0.81 to about 30 wt %, based on the alloy.

31 . An alloy according to claim 1 comprising from about 0.1 at % to about 10.0 at % one or more rare earth elements.

32 . An alloy according to claim 1 comprising Ti, Zr, V, Ni and one or more rare earth elements; or comprising Ti, Zr, Ni, Mn and one or more rare earth elements; or comprising Ti, Cr, V, Ni and one or more rare earth elements; or comprising Ti, Zr, V, Ni, Cr and one or more elements selected from the group consisting of B, Al, Si, Sn and other transition metals; or comprising Ti, Zr, V, Ni, one or more rare earth elements and one or more elements selected from the group consisting of Cr, Mn, Sn, Al, Cu, Mo, W, Fe, Si and Co; or comprising Ti, Zr, V, Ni, one or more rare earth elements and one or more elements selected from the group consisting of Cr, Mn and Al; or comprising Ti, Zr, V, Ni, Cr, Mn, Al, Co and one or more rare earth elements; or comprising Ti, Zr, V, Ni, Cr, Mn, Al, Co and La.

33 . An alloy according to claim 1 comprising about 0.1 to about 60% Ti, about 0.1 to about 40% Zr, 0<V<60%, 0 to about 56% Cr, about 5 to about 22% Mn, about 0.1 to about 57% Ni, 0 to about 3% Sn, about 0.1 to about 10% Al, about 0.1 to about 11% Co and about 0.1 to about 10% one or more rare earth elements; or comprising about 5 to about 15% Ti, about 18 to about 29% Zr, about 3.0 to about 13% V, about 1 to about 10% Cr, about 6 to about 18% Mn, about 29 to about 41% Ni, about 0.1 to about 0.7% Al, about 2 to about 11% Co and about 0.7 to about 8% one or more rare earth elements; or comprising about 11% to about 13% Ti, about 21 to about 23%

Assignees

• Basf Corp

Inventors

• Young Kwo
• Wong Diana
• Reichman Benjamin

Classifications

• H01M4/383

  Hydrogen absorbing alloys · CPC title

• H01M4/385 Primary

  of the type LaNi5 · CPC title

• C22C30/00

  Alloys containing less than 50% by weight of each constituent · CPC title

• Y02E60/50

  Fuel cells · CPC title

• H01M8/083

  Alkaline fuel cells · CPC title