Positive electrode (cathode) materials identification, synthesis, and optimization were accelerated combining computational and experimental methods. A set of practical requirements were imposed prior to the screening in terms of stability, abundance, toxicity, cost and easy synthesis protocol to facilitate upscaling. Through comprehensive DFT calculations performed at Universidad Complutense de Madrid, a variety of transition metal containing structures and compositions were screened and potential cathode materials for Ca-based batteries identified. The electrochemical activity was confirmed in electrochemical cells at Consejo Superior de Investigaciones Científicas. The methodology for materials screening and the selected materials are subject to patenting.