High-throughput screening of stable layered anode materials A2TMO3Cl for chloride-ion batteries

Abstract

The past decade has witnessed rapid advancements in chloride-ion batteries (CIBs), including the development of transition metal chlorides, oxychlorides and layered double hydroxide cathode materials, as well as organic, aqueous, and solid-state electrolyte systems. However, research on anode materials has still been limited to a few strong alkaline metals due to the high demand for Cl⁻ affinity. The inherent insulating chlorinated phase and reconstructed chlorination process of these metallic anodes are the most severe obstacles to the practical application of CIBs. Herein, high-throughput screening is applied to explore the potential anode materials from the layered perovskite oxychlorides (A₂TMO₃Cl). The screened Ca₂CoO₃Cl and Ba₂RhO₃Cl are identified that can maintain their layered structure during electrochemical processes, thereby enabling a stable Cl⁻ (de)intercalation reaction process. Strong alkaline metals in A₂TMO₃Cl are directly connected to Cl⁻, ensuring strong binding ability to meet the requirements of CIB anodes. Meanwhile, transition metal in A₂TMO₃Cl acts as a redox center, which provides Cl⁻ storage capacity and good electrical conductivity. Based on such a layered framework, Ca₂CoO₃Cl and Ba₂RhO₃Cl possess low Cl⁻ diffusion barriers of 0.50 and 0.52 eV, which are numerically and mechanically improved compared to those of the reported CIB anode materials.