Supramolecule-Based Excluded-Volume Electrolytes and Conjugated Sulfonamide Cathodes for High-Voltage and Long-Cycling Aqueous Zinc-Ion Batteries

Abstract

Aqueous zinc-ion batteries (AZIBs) have attracted great attention for sustainable energy storage due to their high safety and low cost. However, the performance of the AZIBs is restricted by electrolyte decomposition, cathode degradation, and anodic dendrite growth. Herein, we propose (2-hydroxypropyl)-β-cyclodextrin electrolytes with synergistic functions of an excluded-volume effect and hydrogen-bond networks, which greatly reduce the activity of water molecules, expand the electrochemical window of the electrolyte, inhibit the dissolution of active materials, and suppress the growth of zinc dendrites. Moreover, organic conjugated sulfonamides are demonstrated to be promising cathodic materials with stable structures and high-potential redox sites. The as-constructed AZIBs exhibit a high open-circuit voltage (1.7 V), a wide operating temperature range (−20 to +90 °C), and long cycling life (with a capacity retention of 98.3% after 2000 cycles at 10 C). The rational design of an organic electrode and an advanced electrolyte is a promising route to boost the overall performances of aqueous secondary batteries.