Control of crystal size tailors the electrochemical performance of α-V₂O₅ as a Mg²⁺ intercalation host

Abstract

α-V2O5 has been extensively explored as a Mg2+ intercalation host with potential as a battery cathode, offering high theoretical capacities and potentials vs Mg2+/Mg. However, large voltage hysteresis is observed...

Phase Control of Multivalent Vanadium Oxides VOx by Ion‐Beam Sputter‐Deposition

“…For instance, vanadium oxides comprise one such prototypical system. Its phases have triggered research in manifold applications such as batteries, [1][2][3][4][5][6][7][8][9][10] electrochromic devices, [11][12][13][14][15][16] and thermochromic smart windows. [17][18][19][20] The different possible oxidation states of vanadium allow for the formation of several binary phases with complex properties.…”

Layered Materials in the Magnesium Ion Batteries: Development History, Materials Structure, and Energy Storage Mechanism

“…Further, a recent study reveals the effect of nanosize V 2 O 5 electrode on the electrochemical performance of RMBs. [ 40 ] Nanoscale and microscale α ‐V 2 O 5 materials were fabricated by a continuous hydrothermal flow synthesis method and evaluated voltage hysteresis and capacity of each electrode. The experimental results clearly deviated from the conventional interpretation of V 2 O 5 material.…”

“…The experimental results clearly deviated from the conventional interpretation of V 2 O 5 material. [ 40 ] Compared to the micro‐sized electrodes, the nanostructure significantly decreased the first cycle voltage hysteresis (1.66 V reduced to 1.08 V), thereby raising the achievable stable capacity (230 up to 310 mAh g −1 ). However, despite nanosized electrodes substantially shortening the ion diffusion distance, the absence of measurable potential hysteresis amelioration in the subsequent charge/discharge cycles demonstrates that the nano‐sized structure only alleviates part of the energy barriers to Mg 2+ insertion and deinsertion.…”

Interlayer Engineering of VS2 Nanosheets via In Situ Aniline Intercalative Polymerization toward Long-Cycling Magnesium-Ion Batteries

“…First, highly polarized divalent Mg 2+ ions have strong Coulombic interactions with cathode materials, which usually leads to sluggish diffusion/insertion kinetics within the crystal lattices of cathode. − In addition, only a few electrolytes can meet high Coulombic efficiency for Mg plating/stripping and satisfying compatibility with existing electrode materials. − Therefore, the development of cathode materials capable to reversibly Mg 2+ storage with high capacity, fast kinetics, and outstanding cycling stability is still a great challenge. − Aurbach’s group first constructed the RMBs using Chevrel phase Mo 6 S 8 as top-performing cathode material in 2000, a milestone development in the field of RMBs. Although Chevrels are considerable for RMBs, their theory discharge capacity (128.8 mA h g –1 ) and low intercalation voltage (1.1 V vs Mg 2+ /Mg) drastically limit their energy density. , Subsequently, only a few cathode materials with gratifying capacity and cycling stability for RMBs have been developed, including transition metal oxides (V 2 O 5 , MnO 2 ), − olivine-phase MgFeSiO 4 , and layered transition-metal chalcogenides (TMCs, MoS 2 , TiS 2 , and WSe 2 ). − Among them, the metal oxides and polyanionic olivine are faced with sluggish kinetics and shaky cycling stability. , In comparison, TMCs exhibit enhanced mobility of Mg 2+ ions , owing to the weaker Coulombic attraction between the “soft” anionic lattices (S or Se) and guest Mg 2+ ions. − …”