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

Abstract

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.

Alloying electrode coatings towards better magnesium batteries

“…Despite the solubility issue, which can be mitigated with polymer synthesis, promising electrochemical cycling could be performed with appropriate electrolytes. [44][45][46][47][48][49][50][51] We used sulphur-impregnated activated carbon clothes (ACC-S, Fig. S14 †) which are commonly used as model electrodes in magnesium batteries despite their limited sulphur loading (10 wt% of sulphur, corresponding to a surface density Fig.…”

Storing Mg Ions in Polymers: A Perspective

“…). Low oxidation stability. The oxidation voltage of commonly used Mg electrolytes is usually below 2.5 V, [ 20,24,40 ] much lower than that of commercial LIBs electrolytes (>4.5 V). Low oxidation stability hinders the utilization of high‐voltage polymer cathodes. MgCl + ‐storage mechanism.…”

“…[41] In addition, poly (phenanthrene quinone) (PFQ) and poly (benzoquinonyldisulfide) (PBQDS) were also reported. [23,24,33,42] Although carbonyl-based polymers have been extensively investigated and remarkably progressed, some challenges still remain unsolved for the practical application. The low operating voltage of carbonyl-based polymers leads to low energy densities.…”

“…Since 1996, various polymers, including carbonyl-, nitrogen-, and sulfur-based polymers, have been reported as cathodes for RMBs (Figure 1). [18][19][20][21][22][23][24] Still, polymer cathodes suffer from low capacities, low conductivity and mismatch with electrolytes, which requires further exploration. In this perspective, we critically discuss the application of polymers as cathodes for RMBs.…”

Redox-active sodium 3,4-dihydroxy anthraquinone-2-sulfonate anchored on reduced graphene oxide for high-performance Zn-ion hybrid capacitors

“…5,20 Additionally, the molecular structure and functional groups can be adjusted to optimize the electrochemical performance. Various quinones and their derivatives have been reported, including anthraquinone, 17,20 phenanthrenequinones, 21 hydroquinone, 22 benzoquinone, 23 etc. Although some progress has been made, there are still some limitations in the practical application of quinone molecules in ESDs.…”