3.3 The Electrochemical Performance of ZMOP-4//PCNTs
ZISCs were assembled by ZMOP-4 cathode, PCNTs anode, and the mixed concentration ZnSO4 (2 M and 0.1 M) electrolyte. The schematic diagram of ZMOP-4//PCNTs ZISCs is shown in Figure 7a . Meanwhile, the electrochemical properties of PCNTs anode as illustrated in Figure S1 . Figure S1a shows CV curves at different sweep speeds, which are similar in shape to rectangles, indicating excellent double-layer characteristics. Figure S1b and c reflect the GCD data and specific capacitance curves of PCNTs at various current densities. The specific capacitance was progressively stabilized. From 0.1 A g-1 to 1 A g-1, the specific capacitances of the PCNTs anode were 633, 306, 177.5, 140, 115, and 81.25 F g-1, demonstrating the remarkable performance of the PCNTs. Furthermore, inFigure 7b , the CV curves of ZMOP-4 and PCNTs at the sweep speed of 1 mV s-1 can be seen, indicating that positive-negative electrodes both had a good response in the window range of 0-0.8 V and 0.8-1.9 V, respectively. Figure 7c and d show the CV curves at different sweep speeds and the GCD data of assembled ZISCs with various current densities, respectively. During the range of 0-1.9 V, the CV curves have typical redox peaks, and all curves have similar shapes at different sweep speeds. The major redox peaks at 0.56 V and 1.28 V, indicating that ZMP-4//PCNTs ZISCs have good pseudocapacitance reaction and high stability. To achieve excellent energy density of ZISCs, the mass ratio between electrodes is very important. Good linear potential time distribution can be seen through the GCD curve, which indicates good capacitance performance. Furthermore, it also indicates that the mass ratio of positive-negative electrodes is appropriate.