Novel Insights into Energy Storage Mechanism of Aqueous Rechargeable Zn/MnO2 Batteries with Participation of Mn2+

作     者：Yongfeng Huang Jian Mou Wenbao Liu Xianli Wang Liubing Dong Feiyu Kang Chengjun Xu 

作者机构：Shenzhen Geim Graphene CenterGraduate School at ShenzhenTsinghua UniversityShenzhen518055People’s Republic of China State Key Laboratory of New Ceramics and Fine ProcessingSchool of Materials Science and EngineeringTsinghua UniversityBeijing100084People’s Republic of China 

出 版 物：《Nano-Micro Letters》 (纳微快报（英文版）)

年 卷 期：2019年第11卷第3期

页      面：227-239页

核心收录：

学科分类：0808[工学-电气工程] 08[工学] 

基　　金：the financial support from the International Science & Technology Cooperation Program of China (No. 2016YFE0102200) Shenzhen Technical Plan Project (No. JCYJ20160301154114273) National Key Basic Research(973) Program of China (No. 2014CB932400) Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program (2017BT01N111) 

主　　题：Zinc-ion battery MnO2 cathode Energy storage mechanism Phase evolution 

摘      要：Aqueous rechargeable Zn/MnO2 zinc-ion batteries(ZIBs)are reviving recently due to their low cost,non-toxicity,and natural ***,their energy storage mechanism remains controversial due to their complicated electrochemical ***,to achieve satisfactory cyclic stability and rate performance of the Zn/MnO2 ZIBs,Mn2+ is introduced in the electrolyte(e.g.,ZnSO4 solution),which leads to more complicated reactions inside the ZIBs ***,based on comprehensive analysis methods including electrochemical analysis and Pourbaix diagram,we provide novel insights into the energy storage mechanism of Zn/MnO2 batteries in the presence of Mn2+.A complex series of electrochemical reactions with the coparticipation of Zn2+,H+,Mn2+,SO42-,and OH-were *** the first discharge process,co-insertion of Zn2+ and H+ promotes the transformation of MnO2 into ZnxMnO4,MnOOH,and Mn2O3,accompanying with increased electrolyte pH and the formation of ZnSO4·3 Zn(OH)2-5 *** the subsequent charge process,ZnxMnO4,MnOOH,and Mn2O3 revert to a-MnO2 with the extraction of Zn2+ and H+,while ZnSO4·3Zn(OH)2·5H2O reacts with Mn2+ to form ZnMn3O7·3 *** the following charge/discharge processes,besides aforementioned electrochemical reactions,Zn2+ reversibly insert into/extract from α-MnO2,ZnxMnO4,and ZnMn3O7·3H2O hosts;ZnSO4·3Zn(OH)2·5 H2O,Zn2Mn3O8,and ZnMn2O4 convert mutually with the participation of Mn2+.This work is believed to provide theoretical guidance for further research on high-performance ZIBs.