Characterization of LiNi_0.8Mn_0.1Co_0.1O₂ (NMC 811) synthesized by molten salt assisted solid-state reaction

¹ Department of Chemical Engineering, Faculty of Engineering, Universitas Sebelas Maret, Surakarta, 57126, Indonesia
² Centre of Excellence for Electrical Energy Storage Technology, Universitas Sebelas Maret, Surakarta, 57146, Indonesia

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

The synthesis of Nickel manganese cobalt (NMC 811) cathode material was studied by comparing the molten salt method and the simple solid-state method. The use of easily decomposed raw materials such as metal oxalate and metal carbonate was further reviewed to determine their effect on the phase purity, crystallinity, and morphology of the NMC 811 material. XRD analysis showed that the material with metal oxalate and the solid-state method (NMC811 S-C2O4) had a hexagonal α-NaFeO2 structure (space group R-3m) with few impurities that are close to the results of commercial NMC 811 material. While samples with metal carbonate (NMC811 S-CO3 and NMC811 M-CO3) detected more impurity phases one of them is Li2CO3. In addition, the ideal structure has not been achieved. SEM results show that raw materials with metal carbonate produce less regular structures, while metal oxalate raw materials produce more uniform spherical primary particles. The molten salt method improves particle homogeneity but faces obstacles in removing impurities due to imperfect washing. These findings emphasize the importance of selecting precursors and synthesis methods to optimize the structural and morphological properties of NMC 811. Optimization of the washing protocol is needed in further research for better molten salt synthesis results. Further studies involving electrochemical performance tests, such as charge–discharge cycling and electrochemical impedance spectroscopy (EIS), are required to fully evaluate the synthesized materials.