β-MnO2 with proton conversion mechanism in rechargeable zinc ion battery

By Wenbao Liu, Xiaoyu Zhang, Yongfeng Huang, B. Jiang, Ziwen Chang, Chengjun Xu, Feiyu Kang. 2021

184 citations recorded by the source corpus.

Abstract Rechargeable aqueous zinc ion battery (RAZIB) is a promising energy storage system due to its high safety, and high capacity. Among them, manganese oxides with low cost and low toxicity have drawn much attention. However, the under-debate proton reaction mechanism and unsatisfactory electrochemical performance limit their applications. Nanorod β-MnO2 synthesized by hydrothermal method is used to investigate the reaction mechanism. As cathode materials for RAZIB, the Zn//β-MnO2 delivers 355 mAh g−1 (based on cathode mass) at 0.1 A g−1, and retain 110 mAh g−1 after 1000 cycles at 0.2 A g−1. Different from conventional zinc ion insertion/extraction mechanism, the proton conversion and Mn ion dissolution/deposition mechanism of β-MnO2 is proposed by analyzing the evolution of phase, structure, morphology, and element of β-MnO2 electrode, the pH change of electrolyte and the determination of intermediate phase MnOOH. Zinc ion, as a kind of Lewis acid, also provides protons through the formation of ZHS in the proton reaction process. This study of reaction mechanism provides a new perspective for the development of Zn//MnO2 battery chemistry.

Subfields: Electrical and Electronic Engineering, Electronic, Optical and Magnetic Materials

View Paper: https://www.semanticscholar.org/paper/45aa1e7b1211d0de68983fb00b6e6ae700834873