Abstract
Zinc ion batteries (ZIBs) are newly emerging and widely attracted energy storage devices owing to its advantages of intrinsic safety and low-cost effectiveness. Herein, we reported a nanorod-like MnO_2 cathode material composited with carbon and pyrrolic nitrogen by in-situ co-precipitation method at room temperature, which was used as ZIB cathode to deliver a high specific capacity of 339 mAh g~(-1) at 100 mA g~(-1) and a long cycle stability over 2000 cycles at 1000 mA g~(-1), resulting in the ultrahigh coulombic efficiencies approximate to 100%. The improved performance was attributed to the enhancement of structural stability and more zinc ion insertion sites after introducing the 2-methylimidazole (2-MI) coating layer. The phase transition of α-MnO_2 @2-methylimidazole (α-MnO_2 @2-MI) and the formation of more porous architecture could be the origin of the continuous capacity increasing in the initial several cycles, which was proved by the results of the ex-situ x-ray diffraction (XRD) and the scanning electronic microscope (SEM). This method can be a more realistic choice for the further commercial applications of low-cost and easily-accessed ZIBs with excellent electrochemical performance.
NSTL
Elsevier