Boosting the Stability of Highly Flexible Cathodes in Zinc-Ion Batteries via the Pillaring Effect of Molybdenum in α-MnO2

Flexible zinc-ion batteries (ZIBs) have been developed by leaps and bounds in recent years. As an important cathode material, the stability of manganese dioxide is crucial to the service life and mechanical endurance of the batteries. Herein, we report the feasibility of using a molybdenum-doped α-MnO2 (MMO) grown on carbon cloth (CC) as a flexible cathode. For CC@MMO electrodes, first, the pillaring effect of the Mo atoms can stabilize the tunnel structure and reduce the energy barrier of Zn2+ migration. The battery has 80 % capacity retention after 1392 cycles at 0.5 A g−1, which is leading the current study. Then, the electrodes exhibit a unique array structure on the microscopic level, in which independently grown nanowires help buffer external stresses and improve the flexibility and stability of the electrodes. The discharge capacity of the assembled flexible battery is maintained at an average of more than 98.3 % of the initial capacity at 2.5 mA cm−2 under different bending angles. And the microstructure of the electrodes is well maintained after 50 times of repeated bending. This work thus presents a flexible cathode with remarkable stability and survivability, which seeks to supplement the present development of advanced energy storage devices.