Efficient Low Temperature Performance of All Solid‐State Zinc‐Air Batteries with MnCo₂O₄/Carbon Fiber Bifunctional Electrocatalyst and Poly(Acrylic Acid) (PAA) Gel Polymer Electrolyte

Abstract

Spinel type MnCo2O4 coated on asphaltene based carbon fibers (MnCo2O4/CF) was used as the electrode material/electrocatalyst for air electrodes for zinc‐air batteries (ZABs). The batteries were assembled using an alkaline poly(acrylic acid) hydrogel electrolyte. The low temperature battery performance of the prepared ZAB cells was studied in terms of charge/discharge voltage and efficiency at different current densities, cycle life, power density, and cell voltage at temperatures between −45 °C and 21 °C. At all temperatures, the ZABs successfully completed 200 cycles of charge/discharge (100 h) at 2 mA cm−2 which is double the current density reported in the recent literature. The maximum power densities at 0 and −45 °C were 75 and 12 mW cm−2, respectively. The good performance is attributed to the porous design of the air electrode and the use of an efficient electrocatalyst and an optimized gel polymer electrolyte.

Catalyst integration within the air electrode in secondary Zn-air batteries

“…In this case, after 200 cycles of 2 mA cm −2 bifunctional cycling, the starting and final efficiencies were 53% and 49%, respectively. At −45 • C (figure 8(j)), the ZAB was less stable and less efficient, but was able to withstand 200 cycles at 2 mA cm −2 without reaching the charge and discharge cutoff voltages of 3.0 V and 0.5 V, respectively [119]. Similar hybrid paste methods have been employed by other researchers, who developed their catalyst loaded nanostructures via microwave [43], hydrothermal [120], solvothermal [27,121], and sol-gel [122] methods.…”