Flexible Three-Dimensional Helical Molybdenum Diselenide Nanorod Arrays for High-Performance Magnesium Rechargeable Batteries

Abstract

Rechargeable magnesium (Mg) batteries have received considerable attention as a promising candidate for next-generation high-performance batteries with the theoretic advantages of lower cost, better safety, and even higher energy density than lithium-ion batteries. In this work, we have created three-dimensional helical nanorod arrays of MoSe2 derived from Mo arrays grown by glancing angle deposition (GLAD) on a polyimide substrate, through a low-temperature plasma-assisted selenization process to form novel cathodes for magnesium ion batteries (MIB). The advanced 3D MoSe2 based MIB cathode shows a specific capacity of 179 mAh g–1 at a current density of 0.1 A g–1 , and maintains 123 mAh g–1 at a current density of 0.1 A g–1 after 200 cycles. A detail investigation of the chemical bonding in MoSe2 cathode during charge and discharge has been taken by Raman, XPS and TEM. Furthermore, we also demonstrated exploratory works on interdigital flexible MIBs and stretchable MIBs, exhibiting a stable output performance under various bending and stretching states. To such selenide nanostructure-based MIBs, this method proves a huge potential for future applications of energy-storage devices in flexible and wearable electronics.