Lithium-sulfur (Li-S) batteries and lithium-selenium (Li-Se) batteries that contain only one single active element have unique advantages and disadvantages. Inspired by ternary lithium batteries, multielement chalcogenide compounds with integrated advantages may improve upon the performance of lithium-chalcogenide batteries at the source. In this work, activated carbon (AC) with an Al2O3@SiO2 heterojunction is used as the carrier, and the performances and mechanisms of elemental substances (X/AC, X = S, Se, and Te) are studied in ether and ester electrolytes as the basis for preparing multielement chalcogenide composites (SST/AC, SST: S-Se-Te compound). In the ester electrolyte system, SST811/AC (where S/Se/Te = 8:1:1, molar ratio) exhibited the best cycling performance, and the capacity remained at 1024.9 mA h g-1 after 300 cycles. The characterization results revealed the mechanisms and sequences of the gradual liquid-phase reactions of SST/AC in ether electrolytes and the direct solid-phase reactions in ester electrolytes. The active elements in SST/AC fully demonstrated their own functions, enabling the effective construction of new lithium-chalcogenide battery systems. This work provides inspiration for the subsequent research of multielement lithium-chalcogenide batteries and paves the way for their application.
Keywords: activated carbon; electrolytes; lithium-chalcogenide batteries; multielement chalcogenide composites; reaction mechanisms.