Opportunities and Challenges in the Development of Cathode Materials for Rechargeable Mg Batteries

Abstract

Recent years have seen an intense and renewed interest in the Mg battery research, naming Mg-S the ≫Holy Grail≪ battery, and expectations that Mg battery system will be able to compete and surpass Li-ion batteries in a matter of years. Considerable progress has been achieved in the field of Mg electrolytes, where several new electrolytes with improved electrochemical performance and favorable chemical properties (non-corrosive, non-nucleophilic) were synthesized. Development in the field of cathodes remains a bit more elusive, with inorganic, sulfur, and organic cathodes all showing their upsides and downsides. This review highlights the recent progress in the field of Mg battery cathodes, paying a special attention to the performance and comparison of the different types of the cathodes. It also aims to define advantages and key challenges in the development of each type of cathodes and finally specific questions that should be addressed in the future research.

Methods and Protocols for Reliable Electrochemical Testing in Post-Li Batteries (Na, K, Mg, and Ca)

“…Such corrosion potentially has an impact on the overall electrochemical response through cycling of copper sulfide species. 49…”

“…83 Thus, any presence of oxygen, water, or other impurities in the electrolyte (even at the ppm level) can lead to inactive passivating films. Several methods have been employed in order to overcome this issue, including the addition of Mg–chloride salts, 84 the use of magnesium powder for which an acceptable degree of Mg free surface could be maintained, 49 and the use of a so-called “conditioning” process, 83,85 which consists of performing several plating and stripping cycles until the stationary electrochemical response is obtained. Therefore, the use of the Mg metal electrode is far from being obvious, and if the nature of its interface with the electrolyte is not carefully considered during battery material testing it can lead to discarding promising electrode or electrolyte materials.…”

Computational Investigation of Chalcogenide Spinel Conductors for All-Solid-State Mg Batteries

“…Magnesium batteries are an interesting alternative to Li-ion technology because of the potential for improved safety and higher energy density. [1][2][3] The ability to use Mg metal as an anode is beneficial because of its high volumetric energy density (3830 mAh/mL) relative to that of graphite (700 mAh/mL), which is generally employed as an anode in Li-ion batteries using liquid or polymer gel electrolytes. 4 Only a few good liquid electrolytes exist for Mg batteries as Mg metal cannot be deposited reversibly in electrolytes that react with the metal.…”

Magnesium batteries: Current picture and missing pieces of the puzzle

“…Discussion about the different types of anode materials is made in close connection to various types of electrolytes (liquid, solid-state, polymer and ionic liquids based) and finally a section on cathode materials classified on the basis of their electrochemical mechanisms, as insertion, conversion and coordination systems, is provided to complete this perspective. With the respect to the other recently published review papers [4,5,6,7,8,9,10,11], the target of this report is to provide for each component of a RMB a critical assessment, evaluated quantitatively in terms of their potential practical performance in a cell (volumetric and gravimetric energy densities). Results shown in Fig.…”