Freestanding MnO2 nanowires/carbon cloth assisted by NH4Br as a cathode for aqueous rechargeable zinc-ion batteries

In terms of renewable energy sources, aqueous rechargeable zinc-ion battery (ARZIB) is a promising candidate to replace lithium-ion batteries. Zn as a major component in ARZIB is low cost, abundant, and nontoxic. MnO₂ as a cathode has a polymorphic structure that can be affected by reduction agent materials. In this study, NH₄Br was used as a reduction agent in the synthesis of MnO₂ nanowires grown in carbon cloth. MnO₂ nanowires/carbon cloth is synthesized by the hydrothermal method at 180 ⁰C for 5 h. As-prepared MnO₂ has nanowires with a diameter range of less than 100 nm. The 1.2 mmol NH₄Br exhibited the best performance among the other variations, with a small R_ct of 38.11 Ω, Coulombic efficiency of 98.79% after 100 cycles, and a specific capacity of 230 mAh g⁻¹ at 100 mA g⁻¹. Therefore, MnO₂ nanowires/carbon cloth is a promising candidate as a cathode material for aqueous rechargeable zinc-ion batteries.