[en] Full text: The growing demand for Li-ion batteries may, in the future, limit the available lithium resources, significantly influencing the cost and the own survival of technology. New materials are investigated to replace the non-abundant and expensive raw materials that constitute the available cathode active material on Li-ion batteries[1]. Among the emerging technologies, the one that uses ion sodium and iron stands out. Sodium orthoferrite, NaFeO₂, shows polymorphism with the α-phase stable up to 770 °C and the β stable at higher temperatures. The α-NaFeO₂ phase presents a lamellar structure that allows the diffusion of Na+ in two dimensions, allowing its use as a cathode of Na+ based batteries[2]. Thus, the objective of this work was to synthesize α-NaFeO₂ via sol-gel route, analyzing its crystallographic, morphological and electrochemical properties. The effect of the chelating agent concentration (citric acid), of the calcination temperature and the time, on the synthesis, were studied. XRD shows the tendency to the formation of the α phase in the 1:1 concentration of citric acid and metals. By Rietveld's refinement of the calcined sample at 600 °C for 4 days it was verified that the only phase containing the iron was α-NaFeO₂ with contamination with Na₂CO₃ of less than 10%. Spherical grains of the order of 200 nm were observed by SEM. Electrochemical performance measurements revealed a low load capacity (20 mAh/g) for which it is attributed to be caused by the surface coating of the α- NaFeO₂ grains with Na₂CO₃. The pure phase obtaining is in progress. References: [1] Vaalma, C.; Buchholz, D.; Weil, M.; Passerini, S. Nature Reviews Materials, v. 3, p. 18013, 2018. [2] Kataoka, R.et al. Electrochimica Acta, v. 182, p. 871-877, 2015. (author)