High-power Mg batteries enabled by heterogeneous enolization redox chemistry and weakly coordinating electrolytes

Abstract

Magnesium batteries have long been pursued as potentially high-energy and safe alternatives to Li-ion batteries; however, fast chargedischarge capability, one of the most desired properties for advanced batteries, remains elusive for this technology. Here, we develop a next generation Mg battery prototype, delivering a specific energy of up to 566 Wh kg 1 and an ultrahigh specific power of up to 30.4 kW kg 1 , which is close to two orders of magnitude higher than state-of-the-art Mg battery. This is achieved by coupling a kinetically fast organic cathode material, operating under bond cleavage-free solidliquid reaction, and an electrolyte capable of providing dendrite-free Mg depositionstripping at a record current density of 20 mA cm 2 .One Sentence Summary: Ultrahigh power, an unprecedented quality of Mg battery, is unveiled and demonstrated using a prototype combining a quinone-based cathode and a second to none Mg(CB 11 H 12 ) 2 electrolyte that enables ultrahigh rate cycling of dendrite-free Mg anode.

Monocarborane cluster as a stable fluorine-free calcium battery electrolyte

“…The highest solubility in the diagram is observed at a solvent ratio of approximately 1/1 (v/v). Similar improvements in solubility have been reported by using mixed solvents for several salts containing cluster-type complex hydride anions, such as Mg(CB 11 H 12 ) 2 , Li 2 B 10 Cl 10 , and Li 2 B 12 Cl 12 29 , 40 . One of the possibility for the improved solubility observed in the present study is that the mixed solvents can be functionalized of the monocarborane cluster anion with one or more moieties 41 .…”

“…The monocarborane cluster anion ([CB 11 H 12 ] − ) is a type of complex hydride anion, which is known as a weakly coordinating anion 20 – 23 . Moreover, due to its high reductive and oxidative stability, it allows for a wide potential window and shows excellent stability against metal anodes such as Li, Na, and Mg 24 – 29 . These led to the idea that an electrolyte with the [CB 11 H 12 ] − anion could also be highly compatible with Ca batteries.…”

Organic Positive Materials for Magnesium Batteries: A Review

“…This technology provides an energy density comparable to the well-known Li-ion battery. [113] In this study, pyrene-4,5,9,10-tetraone (PTO), possibly synthesized by oxidizing pyrene with RuCl 3 .xH 2 O/NaIO 4 [114] or benzyltrimethylammonium fluorochromate [115] (Scheme 12), was identified as the active material for Mg-cell cycling in the boron clusterbased electrolyte Mg(CB 11 H 12 ) 2 (MMC).…”

“…However, an impressive performance in electrochemical processes was Reproduced from ref. [113] with permission from Springer Nature, copyright 2020. discovered for Mg batteries including good retained capacity after 200 cycles and stable Coulombic efficiency. Moreover, PTCDA typically has a large conjugate planar structure where the number of Mg 2 + ions inserted into the active sites can be adjusted by modifying the voltage range.…”

Empowering magnesium

“…Writing in Nature Energy 4 , Rana Mohtadi, Yan Yao and co-workers from the USA propose an ingenious two-pronged strategy to overcome the above-mentioned issues. First, they employ a pyrene-4,5,9,10-tetraone (PTO) cathode.…”