(Invited) Screening Plus Testing of Cathode Materials for Ca and Mg Batteries

Abstract

While the current state-of-the-art in rechargeable batteries is the Li-ion technology, research efforts are intensified towards the development of alternative technologies to satisfy the ever-increasing demand for enhanced energy density. The development of rechargeable batteries based on the intercalation reaction of multivalent cations (Ca2+, Mg2+, Al3+) is a current challenge for electrochemical energy storage. Designing such batteries demands the identification of competitive electrode materials and electrolytes for each particular active ion. In the last years, we have combined computational and experimental techniques in the search of potential cathode materials that could reversibly insert Mg/Ca ions [1-4]. First principles calculations are used to predict three fundamental electrochemical properties of materials: average intercalation voltage, specific capacity and ionic mobility. Benchmarking the computational results with experimental evidences is a necessary step to accelerate reliable materials design based on DFT calculations. Therefore, our experimental investigations comprise the synthesis, characterization and electrochemical testing of materials. In this work, we confront computational and experimental results for selected oxides, nitrides, sulphides and silicate materials. We will show that the combined computational/experimental approaches lead to proof of concept and rationalization for the reversible electrochemical intercalation and deintercalation of calcium in TiS2 [4]. Acknowledgments: Authors are grateful for financial support from Ministerio de Ciencia e Innovación (grant MAT2014-53500-R), the European Union H2020-FETOPEN funded project CARBAT-766617 and Toyota Motor Europe.