Ab Initio Study of the Influence of Structural Defects on the Electrochemical Properties of MnO$_{\mathrm{2}}$ in Rechargeable Zn/MnO$_{\mathrm{2}}$ Alkaline Batteries

ORAL

Abstract

The performance of MnO$_{\mathrm{2}}$ electrodes in rechargeable solid-state alkaline Zn/MnO$_{\mathrm{2\thinspace }}$batteries can be enhanced by nanostructuring and by introducing cation and oxygen vacancies into the crystal structure of MnO$_{\mathrm{2}}$. However, the mechanism of this enhancement has not been investigated in detail. We apply \textit{ab initio} density functional computational methods to study the mechanism of hydrogen ion insertion into the structures of $\beta $-, R-, and $\gamma $-MnO$_{\mathrm{2}}$ polymorphs containing cation vacancies, oxygen vacancies, and surfaces. Our calculations show that the presence of bulk defects and surfaces significantly changes the binding energies of hydrogen ions inserted into the crystal structures of MnO$_{\mathrm{2}}$ polymorphs. The results of our study show that surfaces and structural defects have a strong influence on the electrochemical properties of MnO$_{\mathrm{2}}$.

*This work was supported by the U S Department of Energy, Office of Electricity, and the Laboratory Directed Research and Development program at Sandia National Laboratories

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Authors

  • Nirajan Paudel

    • Department of Physics, New Mexico State University, Las Cruces, New Mexico 88003, USA

  • Birendra Magar

    • Department of Physics, New Mexico State University, Las Cruces, New Mexico 88003, USA

  • Timothy Lambert

    • Department of Materials, Devices, and Energy Technologies, Sandia National Laboratories, Albuquerque, New Mexico 87185, USA

  • Igor vasiliev

    • Department of Physics, New Mexico State University, Las Cruces, New Mexico 88003, USA