Unraveling a High-Performance Self-Supported Flexible Zinc-Ion Battery Cathode with Tailored Electrospun MnO <sub> <i>x</i> </sub> /N-Doped Carbon Nanofibers
Rachendra Akmalia, Faiq Haidar Hamid, Fathiyya Dzikra Azura, Yuyun Irmawati, Qingyu Yan, Afriyanti Sumboja
Abstract
The increasing demand for wearable and bendable electronics has generated significant interest in flexible zinc-ion batteries. However, their development has been hindered by the inadequate capacity and cycling stability of flexible electrodes under repeated mechanical deformation. Herein, we present a self-supported, binder-free, and flexible manganese oxide-based cathode for flexible zinc-ion batteries. This innovation leverages an optimum amount of well-dispersed manganese oxide nanoparticles within a nitrogen-doped carbon nanofiber matrix, achieved by fine-tuning the mass ratio of polyacrylonitrile and manganese acetate during electrospinning. The optimum sample exhibits mechanical robustness and a desirable nanofiber morphology without any bead formations. The synergistic interfaces between manganese oxide nanoparticles and a nitrogen-doped carbon nanofiber matrix facilitate rapid charge transfer and minimize active material detachment, leading to an unprecedented combination of high-rate capability and stability. Consequently, the free-standing cathode can deliver a high specific capacity of 392 mA h g –1 at 0.1 A g –1 and maintain stable capacity (∼200 mA h g –1 ) for up to 1800 cycles at a high current density of 2.0 A g –1 . Furthermore, employing the obtained cathode with a quasi-solid gel electrolyte, flexible zinc-ion batteries achieve stable performance with a high average capacity of ∼186 mA h g –1 over 140 cycles, even under extreme bending angles of 180°. This finding surpasses the performance of the existing flexible zinc-ion batteries and offers a promising path for the development of advanced energy storage solutions in flexible electronics.