Electrochemical properties in Li+ storage. (a) Cycling performance of V2O5@FeOOH-1, V2O5@FeOOH-2, V2O5@FeOOH-5, V2O5·nH2O, and FeOOH at 200 mA g−1. (b) The rate-capacity performance of V2O5@FeOOH-1, V2O5·nH2O, and FeOOH from 100 to 3000 mA g−1. (c) Cyclic voltammetry curves of V2O5@FeOOH-1 at a series of scan rates from 0.2 to 1.0 mV s−1. (d) Normalized contribution ratio of capacitive (orange) and diffusion-controlled (gray) capacities at various scan rates. (e) Schematic illustration for V2O5@FeOOH-1 electrode during Li+ intercalation process.