Sustainable and cost-effective ternary electrolyte EtNHCl-AlCl-Mg(DEP) for high-performance rechargeable magnesium batteries

• Published in: Physical chemistry chemical physics : PCCP Vol. 24; no. 3; pp. 184 - 1848
• Main Authors: Prabhakar, Seggem, Chavan, Santosh N, Basak, Pratyay, Jetti, Vatsala Rani
• Format: Journal Article
• Published: 19.01.2022
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/d1cp04794a

Cost-effective and sustainable battery materials for large-scale batteries are the need of the hour to garner renewable energy with high-performance metal battery technologies. Here, we report the high-performance and long cycle life electrolyte prepared from low-cost triethylamine hydrochloride (Et 3 NHCl) and aluminum chloride (AlCl 3 ) termed as (TA) with different concentrations of magnesium diethylphosphate (Mg(DEP) 2 ) salt. The optimized ratio of the 0.1 M Mg(DEP) 2 electrolyte has shown a high ionic conductivity of 4.5 × 10 −3 S cm −1 at ambient temperature and good anodic stability of 2.41 V vs. Mg/Mg 2+ . The dissolution/deposition of magnesium (Mg) on a Pt working electrode was systematically analyzed in this electrolyte. Cyclic voltammetry (CV) of the Mg-graphite battery was used to probe the intercalation/de-intercalation of Mg-AlCl 4 − ions into/from the graphite layer structure. This was confirmed by various analytical techniques, such as energy dispersive X-ray spectroscopy, X-ray diffraction technique and X-ray photoemission spectroscopy. Notably, during the galvanostatic study analysis, the assembled Mg cell delivered a high discharge capacity of 115 mA h g −1 at a high C/10 rate, with more than 180 cycles at >80% coulombic efficiency. This electrolyte will be helpful in grid-scale power storage systems in future generations. The cost-effective and sustainable electrolyte is needed for scaling up high-performance battery technologies. The simple ternary mixture of Et 3 NHCl-AlCl 3 -Mg(DEP) 2 presented as an effective electrolyte for Mg batteries.