Enhanced Li+ charge storage in naphthalene diimide/vanadium pentoxide intercalates

Abstract

N,N′-Bis(4-aminophenyl)-1,4,5,8-naphthalene diimide (NDI-ph) was intercalated into lamellar vanadium pentoxide (V₂O₅) in different amounts to prepare hybrid intercalates. The presence of the imide supports the material’s ability to form lithium salts with the structural stabilization of the oxide matrix. This effect is remarkable in charge/discharge cycles in terms of Li⁺ uptake and discharge by the lamellar intercalates, as we could double the ion uptake capacity (1.27 Li⁺ per V₂O₅ unit vs. 0.66 for pure V₂O₅), enhance the chemical reversibility and double the specific charge capacity (188 mA h g⁻¹ vs. 98 mA h g⁻¹ for pure V₂O₅) with very small amounts of this imide. This is the first paper dealing with naphthalene diimide intercalates in vanadium pentoxide xerogel for Li⁺ storage.