Fig. 6
From: Rechargeable aqueous zinc-manganese dioxide batteries with high energy and power densities
Function of pre-added Mn2+ in electrolyte. a, b, c, e SEM, d TEM images, and f, g three-electrode-cell EIS analysis of re-obtained cathodes after ten cycles in 3 M Zn(CF3SO3)2 electrolyte a–d, f with and e, g without 0.1 M Mn(CF3SO3)2 additive. Insets of c, d show elemental mapping and SAED pattern, respectively. Insets of f, g show the equivalent circuit to fit the EIS data, where R s, R i, R ct, CPE, and Z w represent series resistance, interface resistance between electrolyte and deposited layer, charge-transfer resistance, constant-phase element, and Warburg diffusion process, respectively. Scale bars, 5 μm a, e; 1 μm b; 10 μm c; 100 nm d; and 5 1/nm (inset of d), respectively
