Facile synthesis of self-supported Mn3O4@C nanotube arrays constituting an ultrastable and high-rate anode for flexible Li-ion batteries

Abstract

An advanced electrode is essential for flexible energy storage devices which enable the application of next-generation flexible electronics. In the current research project, we have designed and fabricated self-supported Mn₃O₄@C nanotube arrays on a conductive substrate via a simple template-assisted route, which can be directly used as a binder-free anode for flexible Li-ion batteries. Such microstructure engineering of electroactive Mn₃O₄ and conductive carbon layers enables the Mn₃O₄@C electrode to possess a high electrical conductivity. The substantial void space in the hollow nanotube and the gap between these 1D nanotube units allow for the full expansion of Mn₃O₄ while preserving the structural integrity of the Mn₃O₄@C self-supported electrode and stable SEI film on the outside carbon surface. As for Li-ion batteries, these binder-free Mn₃O₄@C electrodes exhibit a superior cycling performance (after 3000 cycles at 200 μA cm⁻²/793 mA g⁻¹ with a capacity retention of 552.2 mA h g⁻¹) and excellent rate performance (a reversible capacity of 420, 400 and 375 mA h g⁻¹ at 400/1586, 500/1982 and 600/2380 μA cm⁻²/mA g⁻¹, respectively). The self-supported Mn₃O₄@C nanotube electrode with high flexibility shows its great potential for flexible energy storage devices.