DEVELOPMENT OF C-14 LAVES PHASE ALLOY FOR BATTERY WITH GOOD HIGH-RATEDISCHARGEABILITY

In order to develop C14 type alloys with excellent electrochemical pro perties, alloys with enthalpy - Delta H for hydride formation in the r ange of 35 similar to 37 kJ/molH(2) were designed by using relations a mong - Delta H, cell volume V-C14 of C14 structure, average atomic rad ius rev and ratio of atomic radii r(A/B). Cell volume V-C14 of heat-tr eated alloys at 1353 K for 36 ks was in good agreement with the design ed value. Only a small error of around 1.6 kJ/molH(2) was found betwee n the designed and observed - Delta H values for heat-treated alloys. Many as-cast alloy electrodes showed higher discharge capacities than heat-treated alloys. Discharge capacities of as-cast alloy electrodes were in the range of 376 similar to 408 mAh/g at discharge current den sity of 17 mA/g and 346 similar to 381 mAh/g at 110 mA/g with good hig h-rate capability.