Periodic Reporting for period 1 - Mixed Anion Cathodes (Designing of Novel Mixed Anion Compounds as High Voltage and High Energy Density Sodium-ion Battery Cathodes)
Reporting period: 2021-04-30 to 2023-04-29
(ii) Why is it important for society?: The demand to nullify the greenhouse gases emissions due to climate change without compromising on the Europe’s growing energy demand of 735 GW by 2050 have increased the dependency of renewable energy sources. However, these are intermittent/seasonal and hence, required high energy density storage devices such as batteries. Lithium-ion battery (LIBs) are considered top-notched technology to have powered portable electronics due to their high energy and power density and are therefore, being pursued to electrify plug-in electric vehicles (EVs). However, the current state-of-art LIBs consisted of rare-group elements (Li and Co) which are non-sustainable, scare, non-recyclable and hence, costs high with its growing demand to build EVs. Sodium-ion battery (SIBs) similar in-line with LIBs is considered an alternative due to vast abundance of sodium deposit and hence costs low. However, due to low electrochemical potential (-2.71 V) and large-atomic radius of Na+ couldn’t enable SIB to be used for EVs but could be used for stationary off-grid storage appliances where volume doesn’t matter. With overwhelming increase in global energy consumption, the urge to develop clean technology to store electrical energy from renewable sources are needed as they are crucial to succeed in the decarbonization of energy. Our project to develop high density lithium/sodium batteries is par in alliance with the European policy for off-grid energy storage applications.
(iii) What are the overall objectives?: To develop new synthesis routes to oxyfluorides, by fluorinating layered or tunnel structure of vanadium oxide and to investigate the electrochemical performances of the new oxyfluorides (in half cell configurations) in connection with their structures, microstructure, and morphology. And finally, to investigate the electrochemical performances of full sodium cells with the new materials as positive electrode.
b) Overview of the results: Used solvothermal and/or micro-wave-assisted method to synthesis fluorinated compounds at moderate temperature (≤ 230 °C), we successfully prepared different high energy materials like: V2O3 nanosheets, V4O9 nanoparticles and V4O9-xFx compounds. Followed by materials characterization using various sophisticated analytical techniques to identify the phase and crystal structure, morphology and to understand the valence state and surface functional group of the compounds. This is followed by electrochemical performances of V2O3 as high energy density lithium and sodium storing anode while V4O9 and V4O9-xFx compounds were used as high-capacity lithium and sodium cathodes. Quite successful with electrochemical performances in half-cell configuration while fabrication of full pouch cell configuration is challenging and continue to pursue this target during my extended contract at Host institute.
c) Exploitation and Dissemination Activities: We filed 1 patent application (Nuevo material anódico V2O3 bidimensional libre de material carbonáceos de baja dimensionalidad para para baterías de ion litio (Spanish Patent filed Appl. Number: P202330220, March 16, 2023) while another is in-preparation. After secured the IPR, the manuscripts shall be published in SCI indexed journals. Presented our work in 1 National and 2 international conferences. We propagated the battery science & research to public by each year in the Madrid Science Week and European Research Night.
In these regards, during the project tenure, we have synthesized 3 novel energy materials using earthly abundant and sustainable vanadium element in the form of V2O3, V4O9 and V4O9-xFx, respectively, as high energy density anode and high-capacity cathodes for Lithium and Sodium cells. These materials were prepared by single pot with reduced energy consumption using non-hazardous chemicals are few breakthrough achievements.
In this regard, we have reported/filed: (i) a patent titled: Nuevo material anódico V2O3 bidimensional libre de material carbonáceos de baja dimensionalidad para para baterías de ion litio (Spanish Patent filed Appl. Number: P202330220, March 16, 2023); (ii) We prepared a novel 3D V4O9 cathode material using solvothermal method as superior lithium and sodium insertion materials in the long run (Patent under preparation); (iii) Fluorination of vanadium oxides using non-hazardous fluorinating agents and methods to enable a high voltage sodium cathode (Patent under preparation).