Optimizing Aqueous Zinc‐Sulfur Battery Performance via Regulating Acetonitrile Co‐Solvents and Carbon Nanotube Carriers

Rechargeable aqueous zinc‐sulfur batteries (AZSBs) are gaining attention due to their high energy density, ultra‐stable discharge platform, and safety. However, poor liquid/solid reaction processes at the anode and cathode reduce reaction kinetics, and the severe dissolution of polysulfides causes shuttle effects during discharge/charge cycles, hindering practical applications. Improving performance requires optimizing both the cathode and electrolyte. Herein, we design an organic‐inorganic hybrid electrolyte (zinc trifluoromethanesulfonate and trace iodine monomer dissolved in an acetonitrile/water co‐solvent (AN‐X)) and a partially exfoliated multi‐walled carbon nanotube (PECNT) hosted sulfur (S@PECNTs) cathode for AZSBs. The sulfur is highly dispersed along the PECNTs with appropriate wettability at the electrode/electrolyte interface using AN‐3 as the electrolyte. Meanwhile, this electrolyte inhibits hydrogen evolution at negative potentials and promotes uniform Zn ion stripping/plating. Expressively, the AN‐3‐based AZSB exhibits a high discharge capacity of 1370 mAh g‐1 with excellent Coulombic efficiency (79.9%), outstanding rate capability, and cycling performance. These improvements are attributed to the synergistic effect between the S@PECNTs and the AN‐3 electrolyte, which reduces Rct to enhance reaction kinetics and blocks the dissolution and shuttle effect of polysulfides, ensuring a reversible reaction between zinc and sulfur.