The effect of protons on the Mg²⁺ migration in an α-V₂O₅ cathode for magnesium batteries: a first-principles investigation

Abstract

Via first-principles calculations, we showed that the Mg-ion diffusion energy barrier in α-V2O5 can be substantially decreased through hydrogenation.

Mechanisms of Water-Stimulated Mg2+ Intercalation in Vanadium Oxide: Toward the Development of Hydrated Vanadium Oxide Cathodes for Mg Batteries

“…Similar structural changes following hydrogenation were observed using XPS in a 2016 study by Ma et al (2016). Furthermore, a recent 2019 study by Ni et al (2019) showed that increasing the hydrogen content of V 2 O 5 electrodes by hydrogenation substantially lowers the migration barrier for magnesium-ion insertion. In fact, the migration barrier for α-V 2 O 5 may drop from 1.28 eV without hydrogenation to 0.56 eV when 2 mol of hydrogen are inserted per mole of V 2 O 5 .…”

“…However, as the author notes, there is another potential explanation for the improved performance. On most voltage windows used for the electrochemical insertion of magnesium, the electrolysis of water may occur (2H 2 O → O 2 + 4H + + 4e − ) (Ni et al, 2019). As protons are generated, it is possible that they might be reduced or intercalated at the cathode-electrolyte interface, resulting in higher capacity values being observed.…”

High rate and capacity performances of functionalized MXene/graphene heterostructure anodes for magnesium‐ion batteries

“…The development of electric vehicles and mobile devices motivates an increasing demand to safe and cheap energy storage devices. As a portable power, magnesium‐ion batteries (MIBs) are regarded as the promising next‐generation batteries because of the fascinating advantages including no dendrite formation, small ion radius, excellent safety and abundant element comparing to commercialized lithium‐ion batteries (LIBs) 1‐10 . Developing high performance anodes is necessary for the application of rechargeable ion batteries, which has been made many efforts for LIBs 8,11,12 .…”

“…As a portable power, magnesium-ion batteries (MIBs) are regarded as the promising nextgeneration batteries because of the fascinating advantages including no dendrite formation, small ion radius, excellent safety and abundant element comparing to commercialized lithium-ion batteries (LIBs). [1][2][3][4][5][6][7][8][9][10] Developing high performance anodes is necessary for the application of rechargeable ion batteries, which has been made many efforts for LIBs. 8,11,12 One important challenge for MIBs is that Mg metal is inapplicable to be an anode with traditional electrolytes due to the irreversible formation of insulating passivation layers on the surface of Mg metal, and which can result in failures in the stripping and plating of magnesium.…”

Can doping of transition metal oxide cathode materials increase achievable voltages with multivalent metals?

“…We use, to this end, vanadium pentoxide (V 2 O 5 ), which is a semiconductor and a popular host for mono-and polyvalent cations. [12][13][14][15] Theoretical studies on doped vanadia electrode materials have been limited to interstitial doping by metal intercalation (n-type), [16] as well as hydrogenation [17] and water cointercalation, [18] which have been reported to effectively constitute n-and p-doping, respectively. We also consider other oxides, including those with qualitatively different band compositions, for comparison.…”