Electrochemical Performance of Mg Metal‐Quinone Battery in Chloride‐Free Electrolyte

• Published in: Batteries & supercaps 2021-05, Vol.4 (5), p.815-822
• Main Authors: Pavčnik, Tjaša, Bitenc, Jan, Pirnat, Klemen, Dominko, Robert
• Format: Article
• Language: English
• Subjects: chloride-free electrolytes; ex situ measurements; magnesium rechargeable batteries; organic materials; quinone-based polymers
• ISSN: 2566-6223; 2566-6223
• DOI: 10.1002/batt.202000293

Mg batteries are a promising energy storage system due to the high capacity of the Mg metal anode. However, until recently Mg battery practical application seemed very distant due to corrosive nature of Mg electrolytes and the lack of suitable cathode materials. In this work, we bridge this gap by combining novel chloride‐free Mg electrolyte, Mg perfluorinated pinacolato borate (MgFPB), with quinone based organic cathode. ATR‐IR spectroscopy and complementary energy dispersive X‐ray spectroscopy (EDS) of ex situ cathodes confirm reduction of carbonyl group during discharge an its preferred coordination with Mg2+ cations, although monovalent not fully dissociated MgFPB+cation pairs are detected as well. Mediocre capacity retention of PAQS/CNTs is improved through the use of phenanthrenequinone based polymer (PFQ/rGO). The study demonstrates the promising performance of organic compounds in chloride‐free electrolytes and points towards future steps on the path towards practical Mg metal organic batteries. Teaming up chloride‐free Mg electrolytes with organic cathodes: Mg batteries are one of the most promising future battery technologies due to high capacity and abundance of Mg metal. This work aims to combine state‐of‐the‐art development in the field through the application of organic polymer materials in optimized chloride‐free Mg electrolytes. This combination enables long‐term Mg battery performance with good reversibility. Certain challenges connected with capacity utilization and long‐term stability still remain and are being addressed through the development of novel organic cathodes.