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Rationally Designed Vanadium Pentoxide as High Capacity Insertion Material for Mg‐Ion
Author(s) -
Mukherjee Ayan,
Taragin Sarah,
Aviv Hagit,
Perelshtein Ilana,
Noked Malachi
Publication year - 2020
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.202003518
Subject(s) - pentoxide , materials science , electrolyte , anhydrous , vanadium , electrochemistry , intercalation (chemistry) , cathode , chemical engineering , ion , inorganic chemistry , chemistry , electrode , organic chemistry , metallurgy , engineering
Owing to high energy density and economic viability, rechargeable Mg batteries are considered alternatives to lithium ion batteries. However besides the chevrel phase, none of the conventional inorganic cathode materials demonstrate reversible intercalation/deintercalation of Mg +2 ions in an anhydrous electrolyte system. The lack of high voltage and high capacity cathode frustrates the realization of Mg batteries. Previous studies indicate that vanadium pentoxide (V 2 O 5 ) has the potential to reversibly insert/extract Mg ions. However, many attempts to utilize V 2 O 5 demonstrate limited electrochemical response, due to hindered Mg ion mobility in solid. Here, monodispersed spherical V 2 O 5 with a hierarchical architecture is rationally designed, through a facile and scalable approach. The V 2 O 5 spheres exhibit initial discharge capacity of 225 mA h g −1 which stabilizes at ≈190 mA h g −1 at 10 mA g −1 , much higher than previous reports. The V 2 O 5 spheres exhibit specific discharge capacity of 55 mA h g −1 at moderate current rate (50 mA g −1 ) with negligible fading after 50 cycles (≈5%) and 100 cycle (≈13%), while it retains ≈95% columbic efficiency after 100 cycles demonstrating excellent stability during Mg +2 ion intercalation/deintercalation. Most interestingly, exact phase and morphology are completely retained even after repeated Mg +2 ion intercalation/deintercalation at different current rates, demonstrating pronounced electrochemical activity in an anhydrous magnesium electrolyte.