Sodium-Ion Battery Cathode Material Synthesized By Spray Pyrolysis
In the current study, Na0.44MnO2 was selected due to its promising electrochemical performance, unique structure, and its similarity to transition metal oxides [3, 4]. Figure 1 shows the SEM image of Na0.44MnO2 annealed at 800 ºC. The material demonstrates a uniform, rod-like morphology. Figure 2 displays the XRD data of samples annealed at different temperatures for two hours. Na0.44MnO2 has an orthorhombic lattice cell (pbam space group) and is isostructural with Na4Mn4Ti5O18. The sample annealed at 700 ºC displays impurity peaks around the 30º 2θ. These impure phases may be related to the incomplete decomposition at this temperature. There are no additional phases observed in the 800 ºC and 900 ºC annealed samples. Figure 3 shows the first cycle voltage profile of the Na0.44MnO2 (annealed at 800 ºC) cell at C/10, where 1C equals to 120 mAg-1. The material demonstrates a discharge capacity of 100 mAhg-1, which is comparable to materials reported from other synthesis methods.
1. M.D. Slater, D. Kim, E. Lee, C.S. Johnson, Advanced Functional Materials, Sodium-Ion Batteries, 23(8), 2013, 947-958.
2. V. Palomares, P. Serras, I. Villaluenga, K.B. Hueso, J. Carretero-Gonzalez, T. Rojo, Energy and Environmental Science, Na-ion batteries, recent advances and present challenges to become low cost energy storage systems, 5(3), 2012, 5884-5901.
3. F. Sauvage, L. Laffont, J.M. Tarascon, E. Baudrin, Inorganic Chemistry, Study of the insertion/deinsertion mechanism of sodium into Na0.44MnO2, 46(8), 2007, 3289-3294.