Three-Dimensional Molybdenum Diselenide Helical Nanorod Arrays for High-Performance Aluminium-Ion Batteries.

The rechargeable aluminium-ion battery is a promising candidate for next-generation high-performance batteries, but its cathode materials require more development to improve their capacity and cycling life. We have demonstrated the growth of MoSe2 three-dimensional helical nanorod arrays (HNRAs) on a polyimides (PI) substrate by the deposition of Mo helical nanorod arrays followed by a low-temperature plasma-assisted selenization process to form novel cathodes for AIBs. The binder-free 3D MoSe2-based AIB shows a high specific capacity of 753 mAh g-1 at a current density of 0.3 A g-1 and can be maintained a high specific capacity of 138 mAhg-1 at a current density of 5 A g-1 with 10000 cycles. Ex-situ Raman, XPS and TEM characterization results of the electrodes under different states confirm the reversible alloying conversion and intercalation hybrid mechanism during the discharge and charge cycles. All possible chemical reactions were proposed by the electrochemical curves and characterization. Further exploratory works on interdigital flexible AIBs and stretchable AIBs were demonstrated, exhibiting a steady output capacity under different bending and stretching states. This method provides a new and controllable strategy for selenide nanostructure-based AIBs for use in future applications of energy-storage devices in flexible and wearable electronics.