Facilitating high-capacity V2O5 cathodes with stable two and three Li+ insertion using a hybrid membrane structure consisting of amorphous V2O5 shells coaxially deposited on electrospun carbon nanofibers.

This study reports an approach to achieving stable 2 and 3 Li + insertion, respectively, into vanadium pentoxide (V 2 O 5 ) as lithium-ion battery (LIB) cathode materials using a core-shell structure based on a self-standing carbon nanofiber (CNF) membrane fabricated by an electrospinning process. Uniform coaxial V 2 O 5 shells are coated onto continuous CNF cores via a pulsed electrodeposition. The materials analyses confirm that the V 2 O 5 shell after 4 h of thermal annealing at 300 °C forms a partially hydrated amorphous structure. SEM and TEM images indicate that the uniform 30–50 nm thick V 2 O 5 shell forms an intimate interface with the CNF core. Lithium insertion capacities up to 291 and 429 mAh g −1 are achieved in the voltage ranges of 4.0–2.0 V and 4.0–1.5 V, respectively, which are in good agreement with the theoretical values of 294 mAh g −1 for 2 Li + /V 2 O 5 insertion and 441 mAh g −1 for 3 Li + /V 2 O 5 insertion into crystalline V 2 O 5 materials. Moreover, after 100 cycles, remarkable retention rates of 97% and 70% are obtained for 2 Li + /V 2 O 5 and 3 Li + /V 2 O 5 insertion, respectively. These results reveal that it is potentially feasible to fabricate the core-shell structure with electrospinning and electrodeposition processes to break the intrinsic limits of V 2 O 5 and enabling this high-capacity cathode materials for future LIBs. [ABSTRACT FROM AUTHOR]