•Materials with cationic substitution K(2-x)NaxMn2(SO4)3 (x = 0; 0.5; 1.0; 1.3; 1.4) langbeinite structure were synthesized. It was found that the structure of langbeinite is preserved at x ≤ 0; with further substitution of the potassium cation for sodium, impurity phases appear. Electrochemical replacement of potassium cation with sodium cations in the K2Mn2(SO4)3 material, as well as sodium intercalation-deintercalation, does not occur in the substituted samples.
•- Materials with anionic substitution NaFe(SO4)1.5(A)0.5 were synthesized, where A – SO4, SeO4, HPO4, PO3F. X-ray phase analysis showed the identity of the crystal structure of all four types of samples, regardless of the substituting anion. Additional neutron diffraction studies confirm the successful incorporation of dopants. The discharge capacities of NaFe(SO4)1.5(A)0.5 materials, where A is SO4, SeO4, HPO4, PO3F, were 63, 45, 39, 39 mAh/g, respectively, at a current of 0.1 C in the first cycle . The kinetic parameters of the intercalation-deintercalation processes were determined.
•- The optimal method for applying an electrically conductive layer to the surface of synthesized cathode materials was determined. The influence of the nature of electrically conductive additives on the kinetic and capacitive parameters of the NaFe(SO4)2 cathode material for a sodium-ion battery was studied.
•- Prototypes of “pouch cell” batteries were made from cathode materials NaFe(SO4)2 and NaFe(SO4)1.5(PO3F)0.5 with a practical capacity of 60 and 40 mAh/g at a current of 0.1C.