Oxygen?Deficient β?MnO2@Graphene Oxide Cathode for High?Rate and Long?Life Aqueous Zinc Ion Batteries

• 作者: Shouxiang Ding Mingzheng Zhang Runzhi Qin Jianjun Fang Hengyu Ren Haocong Yi Lele Liu Wenguang Zhao Yang Li Lu Yao Shunning Li Qinghe Zhao Feng Pan
• 来源期刊: 纳微快报（英文版）
• 年，卷（期）: 2021,（11）
• 页码范围: 203-214
• 页数: 12页
• 语种: 英文

摘要

Recent years have witnessed a booming interest in grid-scale electrochemical energy storage, where much attention has been paid to the aqueous zinc ion batteries (AZIBs). Among various cathode materials for AZIBs, manganese oxides have risen to prominence due to their high energy density and low cost. However, sluggish reaction kinetics and poor cycling stability dictate against their practical application. Herein, we demonstrate the combined use of defect engineering and interfacial optimization that can simultaneously promote rate capability and cycling stability of -MnO2 cathodes.β-MnO2 with abundant oxygen vacancies -(VO) and graphene oxide (GO) wrapping is synthesized, in which -VO in the bulk accelerate the charge/discharge kinetics while GO on the surfaces inhibits the Mn dissolution. This electrode shows a sustained reversible capacity of ～ 129.6 mAh -g?1 even after 2000 cycles at a current rate of 4C, outperforming the state-of-the-art -MnO2-based cathodes. The superior performance can be rationalized by the direct interaction between surface -VO and the GO coating layer, as well as the regulation of structural evolution of β-MnO2 during cycling. The combinatorial design scheme in this work offers a practical pathway for obtaining high-rate and long-life cathodes for AZIBs.