In Situ and Operando Analyses of Reaction Mechanisms in Vanadium Oxides for Li‐, Na‐, Zn‐, and Mg‐Ions Batteries

Abstract

Due to their diversity in the composition, lattice structures and physical/chemical properties, and various oxidation states (2+, 3+, 4+, and 5+), (VxOy) nanomaterials have attached much attention for developing new rechargeable batteries, including lithium‐ion batteries (LIBs), sodium‐ion batteries (NIBs), zinc‐ion batteries (ZIBs), and magnesium‐ion batteries (MIBs) as well as new energy storage concepts such as light‐rechargeable batteries. However, to further improve the electrochemical performance of VxOy‐based batteries, it is crucial to understand the various electrochemical mechanisms taking place in these materials for LIBs, NIBs, ZIBs, and MIBs. This review covers a systematical discussion of in situ and operando analysis methods carried out on V2O5, VO2, LixVyOz, NaxVyOz, ZnxVyOz, and MgxVyOz for LIBs, NIBs, ZIBs, and MIBs and the fundamental insights they have provided in the energy storage mechanisms in these batteries.

Carbon‐Coated Electrospun V2O5 Nanofibers as Photoresponsive Cathode for Lithium‐Ion Batteries

“…VO 2 possessing vanadium in the 4þ valence state offers better accessibility of oxidation at relatively lower activation polarization. [45,53,54] CV measurements at different scan rates (0.15-1.2 mV s À1 ) of the photocathode were performed to investigate the influence of light (400 nm, 11 mW cm À2 ) on the electrochemical processes in the voltage window of 2-4 V (Figure S2a-d, Supporting Information). For the CV cycles, which were recorded under light illumination, the redox peak positions were retained, whereas the current density was found to increase indicating the photoresponsive nature of the electrode.…”

“…VO 2 possessing vanadium in the 4+ valence state offers better accessibility of oxidation at relatively lower activation polarization. [ 45,53,54 ]…”

Dual‐Ion Intercalation Chemistry Enabling Hybrid Metal‐Ion Batteries

“…The flexibility of the structure and composition of vanadium oxide (V x O y ) make it suitable as intercalation host for mono-and polyvalent ions such as Li + , Na + , Mg 2 + , and Zn 2 + . [36] By rational manipulation of the structure of V x O y it is possible to gain control over the intercalation of polyvalent ions. [36] The lamellar structure of vanadium oxides has been effectively tuned by simultaneously intercalation of Mg 2 + and polyaniline (PANI), and this serves to enhance their Zn 2 + storage performance.…”

Photo‐Enhanced Magnesium‐Ion Capacitors Using Photoactive Electrodes

“…The asymmetric electrode design used in this work (VO 2 and AC) allows to increase the operating potential of the device, in this case to 1.8 V. [16] VO 2 is selected both because of its bandgap (≈2.3 eV) which is suitable for light harvesting and its framework like structure with large tunnels of ≈0.82 and ≈0.5 nm 2 along b-axis and c-axis that allow for a direct pathway for effective insertion/ extraction of Mg-ions. [13,14,[17][18][19] Figure 1a depicts the energy diagram of the photo-electrodes proposed in this paper, which is designed such that it facilities the extraction of electrons from VO 2 . Light exposure of our Photo-MICs resulted in an enhancement of capacitance with up to 56% at high current densities alongside a 21% higher energy density (light wavelength λ ≈ 455 nm and intensity ≈12 mW cm -2 ).…”