Flexible zinc and manganese dioxide batteries suppressing the formation of zinc dendrite

The zinc-manganese dioxide (Zn-MnO₂) rechargeable batteries can be used for wearable and portable devices due to their environmental friendliness, cost-effectiveness, and high energy density. However, the preparation of Zn-MnO₂ batteries, suppressing the formation of Zn dendrites and maintaining flexibility, remains a significant challenge. To overcome the difficulties, in this study, a flexible Zn-MnO₂ battery that effectively suppresses Zn dendrite formation and maintains its flexibility is suggested. Regarding Zn dendrite, the form of Zn dendrite is favorably modified by handling the number of carbon nanotubes (CNTs) included in buckypaper (BP), while the desirable hexagonal structure of deposited Zn is eventually achieved. By optimizing the Zn deposited onto BP and polydimethylsiloxane (PDMS) substrate (Zn/BP@PDMS anode), flexible Zn-MnO₂ battery prepared with the Zn/BP@PDMS anode exhibits a specific capacity of 0.065 mAh/cm² at 2 mA/cm² and retains 77 % of its initial capacity after 300 cycles, with coulombic efficiency of ∼100 %. Furthermore, the flexible Zn-MnO₂ battery is stably operated even under different bending angles of 45, 90, and 135°, demonstrating its stability and adaptability for wearable and portable devices. Based on that, it is suggested that this flexible Zn-MnO₂ battery can be an important option for next-generation flexible, wearable, and portable energy storage systems.