Hydrogen Storage Alloys

摘要

Hydrogen storage alloys comprising a metal oxide containing≧60 at % oxygen; and/or comprising metal regions separated by a boundary region, which boundary region comprises at least one channel; and/or comprising metal regions separated by a boundary region, where the boundary region has a length and an average width, where the average width is from about 12 nm to about 1100 nm; and/or comprising a metal oxide zone comprising a metal oxide, which oxide zone is aligned with at least one channel; and/or comprising a Ni/Cr metal oxide have improved electrochemical properties, for instance improved low temperature electrochemical performance.

主权项

1. A hydrogen storage alloy having improved low temperature electrochemical properties, comprising a metal oxide containing≧60 at % oxygen, which alloy exhibits
a charge transfer resistance (R) at −40° C. of ≦150 Ω·g; and/or an high rate dischargeability of ≧93% at the 3rd 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 surface catalytic ability for the main phase or main phases at −40° C. of ≦30 seconds; and/or a charge transfer resistance (R) at −40° C. for the main phase or main phases of ≦150 Ω·g.