Royal Society of Chemistry, Journal of Materials Chemistry A: materials for energy and sustainability, 16(2), p. 5809
DOI: 10.1039/c4ta00090k
Full text: Unavailable
Research in the field of lithium-ion batteries favours electrode materials with high surface area. In this context, this paper is dedicated to mesoporous thin films (MTFs) and compares the electrochemical performance of γ-LiV2O5 MTFs with post-synthesis electrochemical lithium intercalation in α-V2O5 MTFs. Formation of vanadium oxide MTFs by soft-chemistry is notoriously difficult. However, it is shown that wormlike vanadium oxide (V–O) and lithium vanadium oxide (Li–V–O) MTFs can be obtained on silicon substrates by a direct sol–gel soft-templating route (evaporation-induced micelle assembly) using a polystyrene-block-poly(ethylene oxide) (PS-b-PEO) structuring agent. Heat treatment for 1 minute at 400 °C (Li–V–O system) or 30 minutes at 350 °C (V–O system) leads to the crystallization of γ-LiV2O5 or α-V2O5, respectively. These calcination conditions ensure the degradation of the structuring agent while preventing the collapse of the mesostructure, yielding MTFs with pore size diameter in the 30–35 nm range. Using the same set of synthesis conditions, films can be deposited on conductive glass substrates for electrochemical investigation: the α-V2O5 films display better specific capacities, while the cyclability is good for both compositions, even at a current density as high as 30 C-rate.