Modified Solid Electrolyte Interphases with Alkali Chloride Additives for Aluminum-Sulfur Batteries with Enhanced Cyclability

Abstract

Al-S batteries are promising energy storage devices, employing high-capacity and low-cost Al (2980 mA h g-1, 8050 mAh cm-3) and sulfur (1672 mAh g-1) as the anode and cathode, respectively. However, Al-S batteries suffer from the notorious shuttle effect of polysulfides as other intensively investigated metal-sulfur batteries. Up to now, several strategies have been proposed to improve the poor reversibility and lifespan of Al-S batteries. At the cathode side, materials that can adsorb polysulfides have been employed as the host material of sulfur to reduce the dissolution of polysulfides,1,2 e.g., heteroatom-functionalized and/or hierarchical porous carbonaceous materials, metal-organic frameworks (MOFs), boron nitrides, and Mxenes.3,4 Nonetheless, AMAs, which also play an important role in the shuttle process, have received little attention up to now. Suitable engineering of electrolytes enabling an electronically insulating solid electrolyte interphase (SEI) on AMAs may suppress the deposition of low-solubility Al2S3 and/or short-chain polysulfides further promoting the cell cycling performance.Herein, alkali chlorides are, for the first time, proposed as electrolyte additives to modify the SEI on AMAs and suppress the polysulfide shuttle in Al-S batteries.5 It is demonstrated that adding NaCl to the conventional [AlCl3]1.3[EmimCl]1 electrolyte can enhance the cyclability of Al-S batteries by forming a thicker, NaxAlyO2-containing SEI layer on AMAs. In addition to NaCl, LiCl and KCl as electrolyte additives also lead to improvement of Al-S batteries’ lifespan. These findings provide a new path to suppress the detrimental polysulfides shuttle effect in Al-S batteries, resulting in their improved cycle performance. References (1) Smajic, J.; Wee, S.; Simoes, F. R. F.; Hedhili, M. N.; Wehbe, N.; Abou-Hamad, E.; Costa, P. M. F. J. Capacity Retention Analysis in Aluminum-Sulfur Batteries. ACS Appl. Energy Mater. 2020, 3 (7), 6805–6814.(2) Zhang, Y.; Ma, L.; Tang, R.; Zheng, X.; Wang, X.; Dong, Y.; Kong, G.; Zhao, F.; Wei, L. The Host Hollow Carbon Nanospheres as Cathode Material for Nonaqueous Room-Temperature Al–S Batteries. Int. J. Hydrogen Energy 2021, 46 (7), 4936–4946.(3) Guo, Y.; Jin, H.; Qi, Z.; Hu, Z.; Ji, H.; Wan, L. J. Carbonized-MOF as a Sulfur Host for Aluminum–Sulfur Batteries with Enhanced Capacity and Cycling Life. Adv. Funct. Mater. 2019, 29 (7), 1–6.(4) Wang, Z.; Zheng, X.; Chen, A.; Han, Y.; Wei, L.; Li, J. Unraveling the Anchoring Effect of MXene-Supported Single Atoms as Cathodes for Aluminum−Sulfur Batteries. ACS Mater. Lett. 2022, 4, 8, 1436-1445.(5) Xu, C.; Diemant, T.; Liu, X.; Passerini, S. Modified Solid Electrolyte Interphases with Alkali Chloride Additives for Aluminum–Sulfur Batteries with Enhanced Cyclability. Adv. Funct. Mater. 2023. 2214405.