Naphthalene Diimides and Vanadium Pentoxide Composite Electrodes for Lithium Ion Batteries

Abstract

N,N′-bis(4-pyridyl)-1,4,5,8-naphthalene diimide (NDI-py) and N,N′-bis(4-benzidine)-1,4,5,8-naphthalene diimide (NDI-bz) were intercalated into lamellar vanadium pentoxide (V2O5·nH2O) xerogels (VXG) in different quantities. Li+ electro-insertion-associated specific charge capacity was considerably improved for the composite electrodes towards pure VXG (125 mA h g–1 for NDI-py3 and 141 mA h g–1 for NDI-bz3 composites vs. 98 mA h g–1 for pure VXG, at 0.1 mA cm–2), even when bearing low imide amounts. Composites charge/discharge cyclability is also enhanced due to the presence of the imides, especially in the case of VXG/NDI-bz composite. Electrochemical impedance spectroscopy results proved that charge transfer at electrolyte/host matrix interface is the limiting step of the lithium ion electro-insertion. The present results are in agreement with the results obtained with N,N′-bis(4-aminophenyl)-1,4,5,8-naphthalene diimide (NDI-ph), and allow a systematic structure/property analysis of V2O5·nH2O/1,4,5,8-naphthalene diimides as cathode materials for Li+ batteries.