Computational high-throughput screening of layered double hydroxides as cathodes for chloride ion batteries

The chloride-ion battery (CIB) based on the anion transfer plays an essential role in developing new battery technologies. As a rare anion intercalated layered material, layered double hydroxide (LDHs) has attracted considerable attention as promising cathodes for CIBs. However, driven by the great compositional diversity, developing a general methodology to effective design and assess the usability of unexploited LDHs for CIBs is still a challenging issue. Herein, a computational high-throughput screening is performed among MII3MIII/IV LDHs (MII = Ni and Co; MIII/IV = Ni, Co, Fe, V, Cr and Ti). When designated as the only guest in LDHs gallery, Cl atoms tend to absorb above the O atoms without MIII/IV around and adsorption energy increases with the order of Ti > Cr > V > Fe > Co > undoped hydroxides. During the chlorination reaction, a special Cl-H-O-MIII/IV electron transfer chain is proposed for the first time. Furthermore, Cl storage performance for 11 cathodes were evacuated by the theoretical voltage in a full CIB system. The results indicates Ti-containing LDHs is the most encouraging cathodes, which is verified by the experimental measurement. This work provides a clear guidance and a theoretical insight into the anion insertion electrochemistry for LDHs materials.