Low temperature synthesis of high electrochemical performance Co_3O_4 nanoparticles for application in supercapacitor

摘要

Nonaggregate and well-crystallized Co_3O_4 nanoparticles with size of 5-15 nm were prepared on a large scale at low temperature by an epoxide precipitation route. The preparation of Co_3O_4 nanoparticles followed the steps of α-Co(OH)_2 formation through epoxide precipitation reactions, conversion of α-Co(OH)_2 to CoOOH in ammonia regulated alkaline suspension, and transformation of CoOOH to Co_3O_4 at 100℃. The small size and nonaggregate state of obtained Co_3O_4 nanoparticles guaranteed the full contact of Co_3O_4 nanoparticles with electrolyte and the complete penetration of electrolyte into the particles. Consequently, the Co_3O_4 nanoparticles presented specific capacitance as high as 879.5 F g~(-1) at scan rate of 5 mV s~(-1) in 1 KOH. Their specific capacitance remain 82.8% of the initial specific capacitance after 5000 charge and discharge cycles. These results demonstrated that these Co_3O_4 nanoparticles can be applied as a high performance electrode material for supercapacitor.