Abstract
Magnesium-ion batteries (MIBs) are potential alternatives to lithium-ion batteries (LIBs) due to the high abundance of magnesium. However, the strong polarization of the divalent charge of Mg 2+ hinders fast ion-diffusion for most cathode materials in comparison to monovalent ions such as Li +. By adding water to dry organic electrolytes, improved electrochemical properties are observed for some electrode materials in MIBs. H 2V 3O 8 is a promising high-capacity cathode material for various battery types such as LIBs and MIBs. We show that both the kinetic and the electrochemical properties of H 2V 3O 8 are improved by adding water to dry organic electrolyte leading to an initial specific capacity of 303 mAh·g −1 at a current density of 50 mA·g −1. This value is approximately four times higher than capacities measured in cells with dry electrolyte. In addition to in depth electrochemical characterization, the structural changes of H 2V 3O 8 are explored by in-operando X-ray diffraction during galvanostatic cycling as a function of the water content in the organic electrolyte. Furthermore, the distribution of Mg 2+ in H 2V 3O 8 is investigated postmortem by transmission electron microscopy. Based on these results a mechanism for Mg 2+insertion into H 2V 3O 8 is proposed and how it is changed by adding water to the organic electrolyte.
Originalsprache | Englisch |
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Aufsatznummer | 141294 |
Fachzeitschrift | Electrochimica Acta |
Jahrgang | 434 |
DOIs | |
Publikationsstatus | Veröffentlicht - 1 Dez. 2022 |
Bibliographische Notiz
Funding Information:TEM measurements were carried out on a JEOL JEM F200 TEM, funded by Interreg Österreich - Bayern 2014 - 2020 Programm-AB29 - "Synthese, Charakterisierung und technologische Fertigungsansätze für den Leichtbau "n2m" (nano-to-macro)". The authors gratefully acknowledge M. Asen for TGA measurements, A. Koopmann for N2-sorption measurements and G. Tippelt for XRD measurements.
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