Improved performance of Li/SOCl2 batteries using binuclear metal azaphthalocyanines as electrocatalysts

A total of twenty four binuclear metal azaphthalocyanine compounds in four series of M2(azaPc)2Me, M2(azaPc)2SO2, M2(azaPc)2, M2(azaPc)2CO (M = Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+) were synthesized by solid phase method, which were applied for Li/SOCl2 battery as electrocatalysts to enhance its capacity and discharge voltage. In all cases, the electrochemical performances of Li/SOCl2 batteries were improved compared with controls. It is worth mentioning that Mn2(azaPc)2SO2 increased the discharge voltage to 3.3485 V, rising by 0.1570 V compared with that of the blank. Co2(azaPc)2CO lengthened the discharge time to 1821 s, rising by 75.80%. And Co2(azaPc)2 raised battery capacity to 35.24 mA h, increasing by 79.56%. Based on cyclic voltammetry measurements, the reaction mechanism was found to involve an irreversible two-step electron transfer process and a hypothesis was conjectured. All the azaphthalocyanine compounds were characterized by element analysis, IR analysis, and UV-Vis absorption.