Sodium titanate nanotube (Na-TNT) sample has been prepared by a hydrothermal method using TiO2 and NaOH as starting materials and then calcined at 400 degrees C in air. X-ray diffraction and N-2 adsorption-desorption tests have been employed to characterize its crystal and pore structure. The Na-TNT can be used as the negative electrode for electric energy storage devices using Na+-based organic electrolytes. The charge storage mechanism at the Na-TNT negative electrode has been investigated by electrochemical tests (galvanostatic charge-discharge, cyclic voltammetry, etc.), ex-situ XRD and HRTEM measurements. The electric energy storage devices of Na-TNT/graphite have been constructed and the influence of graphite/Na-TNT mass ratio on their performance has been studied. (C) 2013 Elsevier B.V. All rights reserved.