Electrochemical Synthesis of Molybdenum Ditelluride (MoTe2) and Its Potential Application as Negative Electrode Material for Sodium Ion Battery

With the rapid expansion in energy demands and depletion of fossil fuel reservoirs, the importance of clean energy production and storage has increased drastically. The renewable energy recourses are cost effective, sustainable and carbon dioxide emission free alternatives. Nevertheless, this energy is not always available and needs to be stored. Lithium-ion batteries (LIBs) are rapidly used in various applications such as powering electronics, electric vehicles and grid energy storage. However, the source of lithium is extremely limited in earth crust, during mining it pollutes the environment and it is costly. Therefore, attention has been shifted towards development of sodium ion batteries (SIBs) which have wide reserves and low precursor cost and thus is considered as an appropriate choice for solar and wind energy development. The prime problem encountered in development of large-scale SIBs is the low effectiveness of appropriate anode material because of large size and sluggish kinetics of Na ions which limits the specific capacity as well as energy density. Metal tellurides have emerged as a promising material for use as negative electrode in sodium-ion batteries due to its unique layered crystal structure, high intrinsic conductivity, and high trap density. Molybdenum ditelluride has more electric conductivity than selenides and sulfides. Other metals except molybdenum in the group takes part in alloying mechanism that leads to higher volume expansion and poor cycling stability. In this study, we describe the synthesis of MoTe 2 on copper and aluminium substrate by using predeposited molybdenum and electrodeposited tellurium at relatively low temperature of 450°C. Further we characterized the samples by X-Ray Diffraction, Raman Spectroscopy and Field Emission Scanning Electron Microscope for structural, elemental, and morphological properties, respectively. The synthesized material was used as negative electrode in sodium ion coin cell. The electrochemical performance of the coin cell will be correlated with the structural and electronic property of MoTe 2 .