Zinc–Air Batteries with an Efficient and Stable MnCo₂O₄/Carbon Fiber Bifunctional Electrocatalyst and a Poly(acrylic Acid)-Based Gel Electrolyte

Efficient and high-performance zinc–air batteries (ZABs) with gel polymer electrolytes (GPEs) were prepared. Cubic spinel-type MnCo2O4-coated carbon fibers (MnCo2O4/CF) were used to prepare air electrodes, and poly(acrylic acid) was used to prepare alkaline GPEs. Materials characterization, including electron microscopy and X-ray photoelectron spectroscopy, confirmed the formation of MnCo2O4 on the CFs. The optimum composition of the GPE was determined by rheological measurements and battery testing; using GPE with a crosslinker concentration of 30 mM led to the best performing battery. Full-cell battery tests and cycling tests showed that this ZAB cell had outstanding performance with an initial efficiency of 62.6% at 10 mA cm–2, which degraded by only 6.5% after 200 cycles (100 h). The power output of this cell was 240 mW cm–2, which is superior to the power outputs reported in the recent literature for ZABs.