Fig. 4. Kinetic analysis of the Li+ storage behavior. (a) Cyclic voltammetry (CV) curves of the (Mg0.2Ti0.2Zn0.2Cu0.2Fe0.2)3O4 electrode for LIBs at different scan rates of 0.1, 0.2, 0.4, 0.6, 0.8 and 1.0 mV s−1. (b) The corresponding logarithm peak current versus logarithm scan rate plots with inset showing the calculated b values. (c) Separation of capacitive (blue region) and diffusion (red region) controlled contribution at 1.0 mV s−1. (d) The normalized contribution ratio of pseudocapacitive capacities at different scan rates for the (Mg0.2Ti0.2Zn0.2Cu0.2Fe0.2)3O4 electrode, which indicates that the electrode was mainly controlled by pseudocapacitive electrochemical behavior.
