Fig. 4

(a) CV curves of CoFe-ZIF@CNTs with different mass of CNTs at the scanning rate of 10 mV s^-1; (b) GCD curves of CoFe-ZIF@CNTs with different mass of CNTs at a current density of 1 A g^-1; (c) Specific capacitance of CoFe-ZIF@CNTs with different mass of CNTs.