Halogen Storage Electrode Materials for Rechargeable Batteries

The ever‐increasing demand for rechargeable batteries with high energy density, abundant resources, and high safety has pushed the development of various battery technologies based on cation, anion, or dual‐ion transfer. The use of halogen storage electrode materials has led to new concept battery systems such as halide‐ion batteries (HIB) and dual‐ion batteries (DIB). This review highlights the recent progress on these electrode materials, including metal (oxy)halides, layered double hydroxides, MXenes, graphite‐based materials, and organic materials with carbon or nitrogen redox centers. The reversible electrochemical halogen storage of halide ions (e.g., F − , Cl − , and Br − ), dual halogen (e.g., Br m Cl n and [ICl 2 ] − ), or binary halide anions (e.g., PF 6 − , AlCl 4 − , [ZnCl x ] 2−x , and [MgCl x ] 2−x ) in the electrodes is covered. The challenges and mechanisms of halogen storage in various electrode materials in HIBs and DIBs are summarized and analyzed, providing insights into the development of high‐performance halogen storage electrode materials for rechargeable batteries.