Alloy Anode Materials for Rechargeable Mg Ion Batteries

Abstract

Rechargeable magnesium ion batteries are interesting as one of the alternative metal ion battery systems to lithium ion batteries due to the wide availability and accessibility of magnesium in the earth's crust. On the one hand, electrolyte solutions in which Mg metal anodes are fully reversible are not suitable for the use of high voltage/high capacity transition metal oxide cathodes due to complex surface phenomena. On the other hand, Mg metal anodes cannot work reversibly in conventional electrolyte solutions in which high voltage/high capacity Mg insertion cathodes can work because of passivation phenomena that fully block them. Replacing Mg metal with alternative anodes that can work reversibly in conventional electrolyte solutions could provide a promising route to elaborate high voltage and high capacity rechargeable Mg battery systems. Herein, the recent progress in alloy anodes based on group IIIA, IVA, VA elements is summarized. The theoretical evaluations, achievable capacities, synthetic strategies, battery test configurations, electrochemical properties, and underlying reaction mechanisms are systematically summarized and discussed. The key issues and challenges impeding their current use are identified and some valuable suggestions for their future development as practical reversible anodes for Mg batteries are provided.

Revealing the Magnesium‐Storage Mechanism in Mesoporous Bismuth via Spectroscopy and Ab‐Initio Simulations

“…However,p oor kinetics associated with the high diffusion barrier of metal ions,a nd the severe volume variations originated from alloying/de-alloying process,a re two key obstacles that prevent wide application of this alloy anode. [21] Delicate structures,s uch as yolk-shell nanospheres for Na + storage, [22] colloidal nanocrystals for Mg-ion battery [13a] and dual-shell boxes for K-ion storage [23] can significantly enhance electrochemical performance by shortening the ion diffusion length. Here,f or the first time,m esoporous Bi nanosheets were loaded onto flexible substrate forming af ree-standing Mg 2+ storage anode.A si si llustrated in Figure S3 and S4, bismuth oxyiodide nanosheet was grown on carbon matrix via afacile hydrothermal approach.…”

Recent Progress and Challenges in the Optimization of Electrode Materials for Rechargeable Magnesium Batteries

“…Moreover, the dendrite-free property (in specific conditions) and high coulombic efficiency in proper electrolytes make it more competitive. [27][28][29][30][31] However, the divalent Mg 2+ ions exhibit sluggish kinetics which originates from the strong polarizing nature and results in low or even no capacity in most cathode materials established for Li-storage. [32][33][34][35] Choosing Mo 6 S 8 as the cathode material is a breakthrough on the way to RMBs and it still surpasses many of cathodes even today, especially in cycling stability.…”

An Overview on Anodes for Magnesium Batteries: Challenges towards a Promising Storage Solution for Renewables

“…One of the most interesting solutions seems to be represented by the rechargeable magnesium-ion batteries (MIBs) [ 92 , 93 , 94 , 95 , 96 ], which utilize magnesium cations as the active charge transporting species in solution and (in many cases) metallic magnesium as the anode. A primary advantage of this technology is given by the solid magnesium anode that leads to high energy density values, well above those of lithium-based cells [ 97 , 98 , 99 , 100 , 101 ]. However, some issues have emerged when using elemental magnesium and novel solutions have been proposed.…”