INFLUENCE OF LAYERED CONDUCTIVE COATINGS ON ELECTROCHEMICAL CHARACTERISTICS OF NaFe(SO4)2 CATHODE MATERIAL

Abstract

Abstract: Introduction. Rising production and consumption, and the high cost of lithium salts
increased the price of lithium-ion batteries. Sodium-ion batteries are a promising replacement as safer and
cheaper. However, the cathode materials for these batteries have low conductivity, which critically
reduces their capacity. Modification with conductive additives is one way to solve this problem. Since a
large electronic contact area of the active material with the conductive coating is required, the main
candidates for such additives are materials with a layered structure. The purpose. To study the influence of
layered conductive additives on the performance and kinetic parameters of eldfellite-structured cathode
material. Methodology. By cyclic voltammetry and galvanostatic methods, it is found that as the 2D
material additive concentration increases, the active material’s performance characteristics initially
increase and then decrease, which is related to the sodium ions diffusion rate through the coating layer.
Results and discussion. As a result of the modification effect evaluation of NaFe(SO4)2 cathode material
with eldfellite structure by layered conductive coatings: graphite, molybdenum disulfide and MXene
(Ti3C2Tx), it was determined that for each material there is a certain optimal concentration at which peak
currents, capacitance and diffusion coefficient are maximized and resistance is minimized. The optimum
additive quantities are 0.5% for MoS2 and MXene, and 0.2% for graphite. Conclusion. The influence of
the concentration of 2D conductive coatings on the electrochemical properties of NaFe(SO4)2 intercalation
material is shown.