MnO2 Heterostructure on Carbon Nanotubes as Cathode Material for Aqueous Zinc-Ion Batteries.

Patchanita Thamyongkit,Sonti Khamsanga,Soorathep Kheawhom,Tetsu Yonezawa,Mai Thanh Nguyen,Adisorn Tuantranont,Rojana Pornprasertsuk,Siwaruk Siwamogsatham,Prasit Pattananuwat

doi:10.3390/ijms21134689

Abstract

Due to their cost effectiveness, high safety, and eco-friendliness, zinc-ion batteries (ZIBs) are receiving much attention nowadays. In the production of rechargeable ZIBs, the cathode plays an important role. Manganese oxide (MnO2) is considered the most promising and widely investigated intercalation cathode material. Nonetheless, MnO2 cathodes are subjected to challenging issues viz. limited capacity, low rate capability and poor cycling stability. It is seen that the MnO2 heterostructure can enable long-term cycling stability in different types of energy devices. Herein, a versatile chemical method for the preparation of MnO2 heterostructure on multi-walled carbon nanotubes (MNH-CNT) is reported. Besides, the synthesized MNH-CNT is composed of δ-MnO2 and γ-MnO2. A ZIB using the MNH-CNT cathode delivers a high initial discharge capacity of 236 mAh g−1 at 400 mA g−1, 108 mAh g−1 at 1600 mA g−1 and excellent cycling stability. A pseudocapacitive behavior investigation demonstrates fast zinc ion diffusion via a diffusion-controlled process with low capacitive contribution. Overall, the MNH-CNT cathode is seen to exhibit superior electrochemical performance. This work presents new opportunities for improving the discharge capacity and cycling stability of aqueous ZIBs.

Highlights

Metal-ion batteries (MIBs) are rechargeable batteries that use metal ions as a charge carrier being capable of reversible intercalation and deintercalation into the host material [1,2,3,4,5]
The cyclic voltammetry (CV) curve of MN-CNT exhibits higher peak intensity and a larger enclosed area when compared with the δ-MnO2, indicating improved electrochemical performance and fast Zn2+ ion insertion/extraction in the cathode [50]
That the MnO2 heterostructure of MN-CNT can improve cycling stability and the rate performance for zinc-ion batteries (ZIBs). This behavior indicates that the MnO2 Heterostructure/MWCNTs (MNH-CNT) cathode can well be considered as Zn2+ ion storage material [52]

Summary

Introduction

Metal-ion batteries (MIBs) are rechargeable batteries that use metal ions as a charge carrier being capable of reversible intercalation and deintercalation into the host material [1,2,3,4,5]. The development of aqueous ZIBs has been limited by the cathode materials used [22,23,24] In this respect, MnO2 has been found to be one of the most promising alternatives due to its low cost and good environmental compatibility along with high operating voltage and a theoretical capacity of 308 mAh g−1 [15,25,26,27]. The MnO2 heterostructure was synthesized leading to an improvement of the electrical conductivity of the cathode and the capacity and cycling stability of ZIBs. the in situ reduction of potassium permanganate (KMnO4) using MWCNTs as a supporting material has been carried out to produce MnO2 heterostructure on multi-walled carbon nanotubes (MNH-CNT). The electrochemical properties and performances of ZIBs which used the MnO2 on multi-walled carbon nanotubes (MN-CNT) as the host material cathode, are investigated and discussed

Results and Discussion

Pseudocapacitive Behavior

Electrodes and Cup Cell Preparation

Materials Characterization

Electrochemical Performances

Conclusions