Graphene-oxide-modified MnO₂ composite electrode for high-performance flexible quasi-solid-state zinc-ion batteries

Rechargeable zinc-based batteries (ZIBs) have attracted broad interests in the large-scale energy storage industry due to the abundant resource, low cost, and high safety of zinc. However, the electrochemical performance of ZIBs still needs to be further improved to meet the increasingly need of energy storage. Herein, the graphene-oxide-(GO)-modified MnO₂ composite electrode (MnO₂-GO/GF) was fabricated via a hydrothermal method, and assembled in a flexible zinc-based battery using polyacrylamide (PAM) as the quasi-solid electrolyte. The proposed battery exhibits excellent charging and discharging time exceeding 13,200 s, as well as 100% retention rate after 2,000 cycles of charging-discharging. In addition to the good resistance against bending deformation, the flexible quasi-solid-state Zn//PAM//MnO₂-GO battery shows outstanding battery capacity of 1250.4 (0.1 mAh·m⁻²) at 10 mA·cm⁻² and robust stability of 91.6% after 5,000 cycles. The results demonstrate that the proposed MnO₂-GO/GF electrode with excellent electrochemical performance and stability has great potential to be employed in the next-generation flexible and wearable devices powered by ZIBs.