Revitalizing Chlorine–Based Batteries for Low–Cost and High–Performance Energy Storage

Abstract

Rechargeable batteries with higher energy densities and sustainability have been intensively pursued in the past decades, driven by the wide applications such as electric vehicle industry and grid energy storage. As an ancient battery system born ≈140 years ago, chlorine (Cl)–based batteries have been actively revisited in recent years, because of their impressive electrochemical performance with the low–cost and sustainable features, making them highly attractive candidates for energy storage applications. In this Perspective, the historical development of Cl–based batteries is reviewed at first, focusing on the progresses in new battery chemistries enabled by various Cl–based electrolytes. An emphasis is then placed on the unique cathode and anode chemistries enabled by rational regulation of Cl–based electrolytes. At last, the challenges and prospects, particularly the obstacles for real–world applications of state–of–the–art Cl–based batteries are introduced.

Rechargeable Seawater-Based Chloride-Ion Batteries Enabled by Covalent Surface Chemistry in MXenes

“…19−21 Among them, aqueous chloride-ion batteries (ACIBs) have drawn attention because of their high theoretical energy densities (2500 Wh L −1 /1100 Wh kg −1 ), stability, and the widespread availability of chloride sources. 22,23 Seawater, a natural chloride-rich electrolyte (approximately 0.54 M), is virtually inexhaustible, comprising 96.5% of Earth's total water reserves. Therefore, using seawater as an electrolyte in rechargeable batteries offers numerous economic and environmental benefits, making them an ideal solution for sustainable energy storage.…”

“…Various anions have been applied as charge carriers in aqueous battery systems, including halides (F – , Cl – , Br – , and I – ), − superhalides ([ZnCl x ] 2– x , [MgCl x ] 2– x , and [LiCl 2 ] − ), − and other oxygen-containing anions (NO 3 – , CO 3 2– , and OH – ). − Among them, aqueous chloride-ion batteries (ACIBs) have drawn attention because of their high theoretical energy densities (2500 Wh L –1 /1100 Wh kg –1 ), stability, and the widespread availability of chloride sources. , Seawater, a natural chloride-rich electrolyte (approximately 0.54 M), is virtually inexhaustible, comprising 96.5% of Earth’s total water reserves. Therefore, using seawater as an electrolyte in rechargeable batteries offers numerous economic and environmental benefits, making them an ideal solution for sustainable energy storage.…”