Electrochemical Effect of Carbon Nanospheres on AB_5 Alloy

Abstract

In this work, we studied hydride forming alloys as negative electrode of Nickel – Metal Hydride (NiMH) batteries. The addition of carbon nanospheres (NEC) to the hydride forming alloy, by means of high energy mechanical milling technique, was investigated. The tested alloy is an AB5 one, elaborated by melting in an induction electric furnace. The carbon nanospheres were synthesized by two steps polymerization of furfuryl alcohol, drying and carbonization, and then doped with different contents of Nickel (0-20 %). Electrochemical activation, cyclic stability, rate capability and electrochemical impedance spectroscopy were studied. The results show that the adding of NEC improve the electrochemical performance with respect to the alloy. The electrodes with no doped NEC and 20 % Ni doped NEC are those that present better electrochemical performance in discharge capacity, rate capability and impedance.