Blocks of molybdenum ditelluride: a high rate anode for sodium-ion battery and full cell prototype study

Manas Ranjan Panda, Anish Raj K, Arnab Ghosh, Ajit Kumar, Divyamahalakshmi Muthuraj, Supriya Sau, Wenzhi Yu, Yupeng Zhang, A. K. Sinha, Matthew Weyland, Qiaoliang Bao, Sagar Mitra

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8 Citations (Scopus)

Abstract

Sodium-ion batteries (SIBs) are considered next-generation rechargeable batteries for grid-scale energy storage applications. This is because sodium is abundant in nature, and SIBs display electrochemical behavior that is similar to lithium-ion batteries (LIBs). Several high-performance sodium-rich cathode materials have been developed, which show excellent electrochemical performance. Nevertheless, the large-scale application of the ultimate metal-free sodium-ion battery that has a full cell configuration is hampered due to unavailability of reliable anode materials. We demonstrated a two-dimensional (2D), layered structured molybdenum di-telluride (MoTe2) as anode material in SIBs through this work. MoTe2 has been synthesized through a facile solid-state reaction route, and it has been used as an anode material without further surface modification or any conductive-coating carbon additives. Synchrotron X-ray diffraction (SXRD) and high-resolution scanning transmission electron microscopy (HRSTEM) confirm the hexagonal structure of MoTe2, which has the space group, P63/mmc. In a half-cell configuration (with respect to sodium metal), the MoTe2 electrode exhibits an initial specific capacity of 320 mA h g−1 at a current density of 1.0 A g−1, and it retains a high capacity of 270 mA h g−1 after 200 cycles. To detect the phase changes during sodiation/desodiation process and to explore the underlying sodium storage mechanism, SXRD, HRTEM with SAD, X-ray photoelectron spectrodcopy (XPS), X-ray absorption near edge structure (XANES) in ex situ mode along with in situ electrochemical impedance spectroscopy (EIS) and quantitative electrochemical kinetic calculations have been used. Further, a sodium-ion full cell is constructed by coupling the MoTe2 as anode and sodium vanadium phosphate Na3V2(PO4)3 (NVP) as cathode. The sodium-ion full cell retains 88% of its initial capacity after 150 cycles at a current density of 0.5 A g−1. Operating at an average potential of ~2 V, the full cell delivers a high energy density of 414 W h kg−1. The present study opens up a new direction to the anode materials for rechargeable sodium-ion batteries.

Original languageEnglish
Article number103951
Number of pages13
JournalNano Energy
Volume64
DOIs
Publication statusPublished - 1 Oct 2019

Keywords

  • Anode materials
  • Molybdenum ditelluride
  • Sodium storage mechanism study
  • Sodium-ion full cell

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