Fig. 4: The electrochemical behavior of three electrolyte systems, 1Zn1Na, ZN3A5·10H2O and ZN3A5·10H2O-EE.

a Columbic Efficiency (CE) of Zn plating/striping reaction measured by Zn/Cu with different electrolyte systems. The dashed line represents the stable CE over 600 cycles in ZN3A5·10H2O_H electrolyte. b Voltage-Capacity curve of Zn||Cu cell with ZN3A5·10H2O-EE electrolyte. c The Zn2+ transference number was measured by electrochemical polarization (the insets are associated with EIS measurements) of Zn||Zn cell in ZN3A5·10H2O-EE. d Cycle performance of Zn||Zn cell at 1 mA cm−2, 1 mAh cm−2 in three electrolyte systems. e Chronoamperogram test of Zn||Zn cell in different electrolyte systems after 10th cycles at a voltage of −150 mV and corresponding SEM morphology characterization of Zn2+ plating in Zn||Zn cell with f 1Zn1Na, g ZN3A5·10H2O and h ZN3A5·10H2O-EE electrolyte. The scale bar: 20 μm in (f), (g) and 10 μm in (h), respectively.