A veritable calcium-ion battery using CaCo2O4 (s.g. P2/m) as a positive electrode, V2O5 (s.g. Pmmn) as a negative electrode and calcium perchlorate in acetonitrile as electrolyte solution has been evaluated for the first time. The electrochemical tests, XRD results and X-ray photoelectron spectra confirm that the calcium ion can be firstly removed from CaCo2O4 and then reintercalated, and this material can be an interesting candidate for developing non-aqueous calcium-ion batteries. (C) 2016 Elsevier B.V. All rights reserved.