A facile biotemplating method has been developed to prepare mesoporous orthorhombic nobium pentoxide (T-Nb2O5) films with ultrahigh lithium ion (Li+) intercalation pseudocapacitance. Nanorod-like cellulose nanocrystals (CNs) with 5-10 nm in width and 100-300 nm in length are produced by the hydrolysis of cotton, which can serve as a novel soft templating agent enabling the straightforward synthesis of mesoporous T-Nb2O5 films. By varying the niobic-to-template ratio, it is possible to tune the surface area and crystallite dimension of the Nb2O5 films. The obtained T-Nb2O5 films show typical capacitive-dominated behaviour in the sweep rate range of 1-20 mV s(-1). It delivers an initial intercalation capacity of 644 C g(-1) at a current density of 0.625 A g(-1), corresponding to x = 1.83 for LixNb2O5, and can still keep relatively stable capacity of 560 C g-1 after 300 cycles. Moreover, its excellent high-rate capability (450 C g(-1) at 12.5 A g(-1)) and wider temperature adaptability present here suggests the promising of T-Nb2O5 as high-energy pseudocapacitor electrode with superior intercalation capacitive behaviour. (C) 2014 Elsevier B.V. All rights reserved.