A Key concept in Magnesium Secondary Battery Electrolytes

Abstract

A critical roadblock toward practical Mg-based energy storage technologies is the lack of reversible electrolytes that are safe and electrochemically stable. Here, we report on high-performance electrolytes based on 1-ethyl-3-methylimidazolium chloride (EMImCl) doped with AlCl3 and highly amorphous δ-MgCl2 . The phase diagram of the electrolytes reveals the presence of four thermal transitions that strongly depend on salt content. High-level density functional theory (DFT)-based electronic structure calculations substantiate the structural and vibrational assignment of the coordination complexes. A 3D chloride-concatenated dynamic network model accounts for the outstanding redox behaviour and the electric and magnetic properties, providing insight into the conduction mechanism of the electrolytes. Mg anode cells assembled using the electrolytes were cyclically discharged at a high rate (35 mA g(-1) ), exhibiting an initial capacity of 80 mA h g(-1) and a steady-state voltage of 2.3 V.

Magnesium Ethylenediamine Borohydride as Solid-State Electrolyte for Magnesium Batteries

“…demonstrated the first fully inorganic and halide-free Mg electrolytes enabling reversible Mg plating and stripping78. In an effort to improve the safety, attempts have been made to replace the flammable organic solvents by ionic liquids91011.…”

Anthraquinone‐Based Polymer as Cathode in Rechargeable Magnesium Batteries

“…Although the first prototype Mg battery using stable Mo 6 S 8 as cathode was introduced over fifteen years ago, major challenges remain to be solved. [4][5][6][7][8] There is also intensiver esearch going on in the field of ionic liquid electrolytes, [9,10] which could offer safer Mg electrolytes regarding their flammability and volatility.N on-nucleophilic electrolytes with high oxidative stability open the possibility to employ organic materials in which weaki ntermolecularf orces enabler eversible electrochemical interactions and fast diffusion of Mg cations. Herein, we present an ew,g eneral, and robust approach towards achieving stable cycling of Mg batteries.…”

“…[4][5][6][7][8] There is also intensiver esearch going on in the field of ionic liquid electrolytes, [9,10] which could offer safer Mg electrolytes regarding their flammability and volatility.N on-nucleophilic electrolytes with high oxidative stability open the possibility to employ organic materials in which weaki ntermolecularf orces enabler eversible electrochemical interactions and fast diffusion of Mg cations. [4][5][6][7][8] There is also intensiver esearch going on in the field of ionic liquid electrolytes, [9,10] which could offer safer Mg electrolytes regarding their flammability and volatility.N on-nucleophilic electrolytes with high oxidative stability open the possibility to employ organic materials in which weaki ntermolecularf orces enabler eversible electrochemical interactions and fast diffusion of Mg cations.…”

Magnesium Borohydride-Based Electrolytes Containing 1-butyl-1-methylpiperidinium bis(trifluoromethyl sulfonyl)imide Ionic Liquid for Rechargeable Magnesium Batteries

“…Recently, Bertasi et al reported Mg electrolytes based on 1-ethyl-3-methylimidazolium chloride (EMImCl) with AlCl 3 and amorphous δ-MgCl 2 exhibited highly reversible behavior. 37 2 , IL solvents BMIM-TFSI (l-n-butyl-3-methylimidazolium bis(trifluoromethyl sulfonyl)imide), PP 13 -TFSI (N-methyl-N-propylpiperidinium bis(trifluoromethyl sulfonyl)imide), and DEME-BF 4 (N,N-diethyl-N-methyl(2-methoxyethyl)-ammonium tetrafluoroborate), and DME and ACN (acetonitrile) organic cosolvents. 38 The failure owes to the strong coulombic attraction between the anions and the extremely charge-dense Mg 2+ cation, which prevents dissociation in solution to produce solvated mobile Mg 2+ and the strong association could not 27 In view of few reports about the compatibility of ILs-based magnesium electrolytes with cathodes, an appropriate electrolyte formulation for Mg batteries and hybrid Mg-Li batteries was further identified for practical application.…”