The mechanism of the sodiation and desodiation in Super P carbon electrode for sodium-ion battery

• Published in: Journal of power sources Vol. 340; pp. 14 - 21
• Main Authors: Wu, Chun-Ming, Pan, Ping-I., Cheng, Yin-Wei, Liu, Chuan-Pu, Chang, Chia-Chin, Avdeev, Maxim, Lin, Shih-kang
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.02.2017
• Subjects: Anode; Neutron powder diffraction; Sodium-ion battery; Super P carbon; Super P carbon; Sodium-ion battery; Anode; Neutron powder diffraction
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2016.11.048

The sodiation and desodiation of sodium (Na) into the Super-P carbon anode material were investigated using electrochemical analyses, high-resolution transmission electron microscopy (HRTEM), and neutron powder diffraction (NPD). In the sodiated Super-P carbon, sodium is stored both in the graphite interlayer space of carbon nano-particles and pores between the particles. Sodium metal clusters found in micro-pores between the carbon particles are responsible for the large irreversible capacity of the Super-P electrode. The graphite interlayer distance increases on sodiation from 3.57 Å to two distinct values of ∼3.84 and 4.41 Å. The mechanism of the process is discussed. The sodiation/desodiation mechanism of the Super P carbon. [Display omitted] •Super P (SP) consists of few-layer-thick graphite, interlayer distance ca. 0.357 nm.•The graphitic layer distance increases on sodiation to ∼3.84 and 4.41 Å.•Metallic Na plating were observed at the micro-pores between the carbon particles.•Pathways of Na+ into graphite layers and micro-pores were proposed.