A review on realizing rechargeable batteries based on SOCl2/SO2 electrolyte systems

As representative high‐energy density primary batteries, Li‐SOCl2 and Li‐SO2 batteries possess superiorities including high working potential, long temperature range, low self‐discharge rate and high safety compared with other conventional primary batteries. In spite of the high energy features, these devices have only been applied for single discharge rather than achieved energy cyclic utilization via recharge. Various modifying strategies have been put out concerning the two electrolyte systems to liberate theoretical energy storage capability as much as possible over decades. Nevertheless, reversible chemistry is also urgently required nowadays for these sulfur‐based electrolyte primary batteries to achieve transformation and upgrading. In the review, we collect some of the modification works for Li‐SOCl2 and Li‐SO2 primary batteries since their invention and successively introduce some of the opening research studies of secondary batteries, designed technologies of which are demonstrated through aspects through anode interface, cathode materials, and electrolyte composition. Finally, it is aiming to look further into the future development of the reversibility of the unique electrolyte systems.