Na4Mn9O18/Carbon Nanotube Composite as a High Electrochemical Performance Material for Aqueous Sodium-Ion Batteries

摘要

The aqueous sodium-ion battery (ASIB) is one of the promising new energy storage systems owing to the abundant resources of sodium as well as efficiency and safety of electrolyte. Herein, we report an ASIB system with Na4Mn9O18/carbon nanotube (NMO/CNT) as cathode, metal Zn as anode and a novel Na⁺/Zn²⁺ mixed ion as electrolyte. The NMO/CNT with microspherical structure is prepared by a simple spray-drying method. The prepared battery delivers a high reversible specific capacity and stable cyclability. Furthermore, the battery displays a stable reversible discharge capacity of 53.2 mAh g⁻¹ even at a high current rate of 4 C after 150 cycles. Our results confirm that the NMO/CNT composite is a promising electrode cathode material for ASIBs.