Fig. 7. (a) Rate performances of polysulfide@TFPPy–ETTA–COF (red) and S@TFPPy–ETTA–COF (blue). (b) Charge–discharge curves of polysulfide@TFPPy–ETTA–COF at different rates. (c) Nyquist plots of polysulfide@TFPPy–ETTA–COF (red) and S@TFPPy–ETTA–COF (blue).