Porous MoO3 films are obtained by electrodepositing on Ni substrates. The galvanostatic charge/discharge tests show that, the film cathodes have a reversible capacity of 190mAhg−1 at a current density of 30mAg−1 between the voltage limits of 1.5–3.5V vs. Li+/Li, a much better performance than the pristine MoO3 powder. More than 75% capacitive contribution in the capacity of porous MoO3 films is responsible for the high capacity, according to the cyclic voltammetry analysis. Another improved property of the porous MoO3 films is the rate performance, which still retains 70 mAhg−1 at a current density of 1.25Ag−1. The chronopotentiometry results reveal that, the prominent rate performances are owing to the high rate ability of the capacitive contribution.