Na0.44MnO2 (NMO) is one of the most promising positive electrode materials for the development of sodium ion secondary batteries. In this work, a NMO orthorhombic compound was prepared by a soft chemistry modified Pechini method and characterized. The material exhibits a good discharge capacity (about 110mAh/g) at low current rate (11 mA/g, C/25) which decreases to 65mAh/g at high rate (275mA/g, 1C). The electrochemical behavior was investigated by the extensive use of electrochemical impedance spectroscopy analysis. It was observed that the kinetic limitations are mainly due to the low diffusion coefficient of Na+ ions in the structure (in the range 10-13/10-14 cm2/s) and to the high values of the surface resistance which is the sum of two contributes attributed to the charge transfer process and the presence of a passivating layer. The diffusion coefficient as well as the charge transfer resistance depends on the sodium amount in the electrode. © 2013 Elsevier Ltd. All rights reserved.

Ruffo, R., Fathi, R., Kim, D., Jung, Y., Mari, C., Kim, D. (2013). Impedance analysis of Na0.44MnO2 positive electrode for reversible sodium batteries in organic electrolyte. ELECTROCHIMICA ACTA, 108, 575-582 [10.1016/j.electacta.2013.07.009].

Impedance analysis of Na0.44MnO2 positive electrode for reversible sodium batteries in organic electrolyte

RUFFO, RICCARDO;FATHI, REZA;MARI, CLAUDIO MARIA;
2013

Abstract

Na0.44MnO2 (NMO) is one of the most promising positive electrode materials for the development of sodium ion secondary batteries. In this work, a NMO orthorhombic compound was prepared by a soft chemistry modified Pechini method and characterized. The material exhibits a good discharge capacity (about 110mAh/g) at low current rate (11 mA/g, C/25) which decreases to 65mAh/g at high rate (275mA/g, 1C). The electrochemical behavior was investigated by the extensive use of electrochemical impedance spectroscopy analysis. It was observed that the kinetic limitations are mainly due to the low diffusion coefficient of Na+ ions in the structure (in the range 10-13/10-14 cm2/s) and to the high values of the surface resistance which is the sum of two contributes attributed to the charge transfer process and the presence of a passivating layer. The diffusion coefficient as well as the charge transfer resistance depends on the sodium amount in the electrode. © 2013 Elsevier Ltd. All rights reserved.
Articolo in rivista - Articolo scientifico
Cathode materials; Charge transfer process; Charge transfer resistance; Electrochemical behaviors; Impedance spectroscopy; Positive electrode materials; Sodium ion batteries; Solid-state diffusion
English
2013
108
575
582
none
Ruffo, R., Fathi, R., Kim, D., Jung, Y., Mari, C., Kim, D. (2013). Impedance analysis of Na0.44MnO2 positive electrode for reversible sodium batteries in organic electrolyte. ELECTROCHIMICA ACTA, 108, 575-582 [10.1016/j.electacta.2013.07.009].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/47184
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