Fig. 3: Electrochemical characterizations of electrolytes and negative electrode.

a Plots of conductivity versus temperature for zwitterionic (Zw), poly zinc 2-acrylamido-2-methylpropanesulfonate (PAMPS), and polyacrylamide (PAM) soaked in 3 m Zn(ClO4)2 with 40 wt% maltose and liquid electrolyte (LE). b Electrochemical stability window of different electrolytes. c Direct current (DC) polarization curve of CZHE at 25 °C, inset shows electrochemical impedance spectroscopy plots before and after DC polarization. d Long Zn plating/stripping behavior and (e) Rate capability of symmetrical Zn | |Zn cells with different electrolytes. f Zn plating/stripping behavior under different temperatures after rate test. g Long-term cycle performance of Zn | |Ti asymmetric cells with different electrolytes at an upper cut-off voltage of 0.5 V. h Selected voltage-capacity profiles of Zn | |Ti with CZHE.