Electrochemical properties of Cu2O/Cu composite particles prepared by a novel and facile method

Highlights: → A novel and simple chemical precipitation route was used to synthesize octahedral Cu2O particles. → The electrochemical behavior of the Cu2O electrode in alkaline solution was investigated systematically. - Abstract: Cu2O/Cu composite particles were synthesized by a novel and facile chemical reduction method without any template or surfactant. X-ray diffraction (XRD) results showed that the product mainly consisted of the Cu2O phase coexisting with a few Cu phases. Typical FE-SEM images indicated that the particles with an octahedral shape were Cu2O. In addition, the electrochemical performance of the Cu2O/Cu particles as the working electrode material in alkaline solution was systematically investigated. The particles showed a maximum discharge capacity of 222.9 mAh g-1 at a discharge current density of 60 mA g-1 and a high value of 109.1 mAh g-1 after 50 charge-discharge cycles. The results of cyclic voltammetry demonstrated that the reaction between Cu2O and Cu is the major electrochemical reaction during the charging and discharging process. The results of electrochemical impedance spectroscopy indicated that the formation of Cu2O on the surface of Cu particles significantly increased the contact resistance and the charge transfer resistance of the electrode during the discharging process.