Electrodeposition of MnO2 nanoflakes onto carbon nanotube film towards high-performance flexible quasi-solid-state Zn-MnO2 batteries

Abstract Flexible aqueous zinc-ion batteries are promising to satisfy the booming wearable electronics. Herein, a facile, scalable, and cost-effective method (one-step electrodeposition) is developed to grow MnO2 nanoflakes onto carbon nanotube (CNT) film. The binder-free self-supporting CNT@MnO2 film can take advantages of highly conductive CNT scaffold and nanostructure of MnO2, thus leading to facilitated electrochemical kinetics. Based on the CNT@MnO2 film, a flexible quasi-solid-state Zn-MnO2 battery is assembled and achieves high reversible capacity of 292.7 mAh g−1 (corresponding to 16.5 mWh cm−3) at 0.2 mA cm−2, great rate capability (105.6 mAh g−1 at 3 mA cm−2), and excellent cycling stability (no capacity fading after 1000 cycles). The quasi-solid-state Zn-MnO2 battery also shows high tolerance to mechanical bending. With these merits, the CNT@MnO2 film holds great potential for Zn-MnO2 batteries to power wearable electronics.