Effects of electrolytes and temperature on high-rate discharge behavior of MmNi5-based hydrogen storage alloys

A series of experiments have been performed to investigate the effects of electrolyte composition and temperature on the high-rate discharge behaviors of MmNi(5)-based AB(5) hydrogen storage alloy electrodes Two types of AB(5) electrodes have been used using different alloys Ce-nch alloy V (La-0 26 Ce0 44Pr0 1Nd0 2Ni3 55Co0 72Mn0 43Al0 (3)) and La-nch alloy N (La-0 Ce-58(0) Pr-25(0) (06) Nd0 11Ni3 66Co0 74Mn0 41Al0 18) Electrolytes EN were obtained by adding a saturated amount of Al-2(SO4)(3) to the onginal electrolyte EO (6 M KOH + 1 wt% LiOH) The electrolyte EN has previously been shown to be very effective to stop the self-discharge of the AB(5) electrodes, better charge/discharge cycle life have been observed The electrochemical properties of the electrodes were measured by two methods step mode high-rate discharge and continuous mode high-rate discharge The results indicate that at 298 K and 333 K, high-rate discharge capacity of Ni-MH battery was mostly affected by the chemical composition of the electrolyte, then the type of alloy Better discharge abilities in high-rate discharge capacity have been observed in electrolyte EO than in electrolyte EN The Ce-nch alloy V has a higher high-rate discharge capacity than La-nch alloy N High-rate discharge capacity decreases in the following order VEO > NEO > VEN > NEN (VEO denotes the combination of alloy V and electrolyte EO used in the test battery, similarly equivalent representations for NEN, VEO and VEN) (C) 2010 Professor T Nejat Veziroglu Published by Elsevier Ltd. All rights reserved.