Modulating residual ammonium in MnO2 for high-rate aqueous zinc-ion batteries

Yancheng Fu; Caoer Jia; Zihan Chen; Xiaosheng Zhang; Shuaijie Liang; Zhen Zhai; Jinzhou Chen; Xuying Liu; Linlin Zhang

doi:10.1039/d1nr07406g

Modulating residual ammonium in MnO₂ for high-rate aqueous zinc-ion batteries

Nanoscale. 2022 Feb 24;14(8):3242-3249. doi: 10.1039/d1nr07406g.

Authors

Yancheng Fu¹, Caoer Jia¹, Zihan Chen¹, Xiaosheng Zhang¹, Shuaijie Liang¹, Zhen Zhai¹, Jinzhou Chen¹, Xuying Liu¹, Linlin Zhang^{1

2}

Affiliations

¹ The Key Laboratory of Material Processing and Mold of Ministry of Education, Henan Key Laboratory of Advanced Nylon Materials and Application, School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001, P. R. China. zhangll@zzu.edu.cn.
² Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), College of Chemistry, Nankai University, Tianjin 300071, P. R. China.

PMID: 35156981
DOI: 10.1039/d1nr07406g

Abstract

Manganese dioxide (MnO₂), as a promising cathode candidate, has attracted great attention in aqueous zinc ion batteries (ZIBs). However, the undesirable dissolution of Mn²⁺ and the sluggish kinetic reaction are still two challenges to overcome before achieving good cycling stability and high-rate performance of ZIBs. Herein, β-MnO₂ with chemically residual NH₄⁺ (NMO) was successfully fabricated by controlling the washing condition and utilized as a cathode in a ZIB. Interestingly, NH₄⁺, as a layer pillar in the tunnel structure of NMO, could enhance its conductivity by changing the chemical structure, contributing to accelerating the kinetics of the charge carrier. Moreover, the residual NH₄⁺ in NMO could stabilize the chemical microstructure through the cationic electrostatic shielding effect and the formation of Mn-O⋯H bonds in NMO, promoting the reversible and successive insertion/extraction of H⁺/Zn²⁺ in the ZIB. As a result, the Zn/NMO battery exhibits excellent rate performance (up to 8.0 A g^-1) and cycling stability (10 000 cycles). This work will pave the way for the design of cathode materials with nonmetallic doping for high-performance ZIB systems.