H. Senoh et al., Charge efficiency of misch metal-based hydrogen storage alloy electrodes at relatively low temperatures, ELECTR ACT, 46(7), 2001, pp. 967-971
Charge efficiency of Mm (misch metal)-based hydrogen storage alloy (MmNi(3.
6)Mn(0.4)Al(0.3)Co(0.7)) electrode was evaluated in the temperature range o
f 25 to -40 degreesC. The charge efficiency obviously decreased less than 0
degreesC. From the rate of hydrogen absorption in solid-gas phase, exchang
e current density and charge-transfer resistance measured at various temper
atures, it was inferred that the rate-determining step in the charge proces
s of the negative electrode at relatively low temperatures was the charge-t
ransfer reaction on the electrode surface. The addition of Mo to the alloy
was effective for improving the electrocatalytic activity, leading to the i
mprovement of the charge efficiency at relatively low temperatures. (C) 200
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