Microwave calcination as a novel route to prepare high performance Mg-doped Na2/3Ni1/3Mn2/3O2 cathodes for sodium-ion batteries

• Published in: Journal of electroanalytical chemistry (Lausanne, Switzerland) Vol. 930; p. 117157
• Main Authors: Bomio, Mauricio, Lavela, Pedro, Tranquilin, Ricardo Luis, Motta, Fabiana Villela da, Tirado, José Luis
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.02.2023
• Subjects: Layered oxides; Magnesium; Microwave calcination; Sodium-ion batteries; Magnesium; Layered oxides; Sodium-ion batteries; Microwave calcination
• ISSN: 1572-6657; 1873-2569
• DOI: 10.1016/j.jelechem.2023.117157

•Mg-doped Na2/3Ni1/3Mn2/3O2 samples are obtained by a rapid microwave-calcination.•Highly pure samples are obtained for short annealing times.•Microwave calcination favors the OP4 phase as compared to conventional one.•The superior cycling performance of microwave-calcined sample is evidenced at −15 °C. Microwave calcination is proposed as an alternative to conventional heating in an electric furnace to provide high performance electrodes for sodium-ion batteries. The short annealing time was compatible with the preparation of pure and highly crystalline Mg-doped Na2/3Ni1/3Mn2/3O2 samples. The kinetic response of the electrode samples at three distinct stages of the galvanostatic cycling evidenced the better electrochemical performance of the microwave calcined samples as compared with a reference sample prepared by conventional heating procedures. The higher crystallite size and lower microstrains observed by microwave annealing is crucial to provide a positive electrode with less resistive behavior at high rates, higher Na+ diffusion coefficient, and lower cell internal resistance.