Adsorbed Water on Nano-Silicon Powder and Its Effects on Charge and Discharge Characteristics as Anode in Lithium-Ion Batteries. Issue 1 (4th October 2016)

• Record Type: Journal Article
• Authors: Yoshida, Shuhei; Masuo, Yuta; Shibata, Daisuke; Haruta, Masakazu; Doi, Takayuki; Inaba, Minoru
• Is Part Of: Journal of the Electrochemical Society. Volume 164:Issue 1(2017)
• Page Start: A6084
• Page End: A6087
• Publication Date: 2016-10-04
• Subjects: Adsorbed water -- Coulombic efficiency -- Gas -- Irreversible capacity -- Nano-sized silicon -- SEI; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.01111701jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : The amounts of adsorbed water on several kinds of carbon and silicon materials including Si nano-flake powder (Si LeafPowder, Si-LP) were determined at 250°C. It was found that nano-sized Si materials adsorb a large amount of water even after being dried at 120°C because of the hydrophilicity of the surface and the high specific surface area. The adsorbed water on Si-LP can be removed, but not completely, after drying at a 180°C. The charge and discharge characteristics of Si-LP, especially the initial irreversible capacity and the coulombic efficiencies upon repeated cycling, were significantly improved by removal of the adsorbed water at 180°C. The 180°C-dried sample also suppressed gas evolution during the initial charging and discharging cycle. From the results of gas analysis, it was found that gases evolved from the Si-LP electrodes were mainly H2 and CO2 . From the results of charge and discharge tests and gas analysis, the effect of the adsorbed water on the irreversible decomposition of the electrolyte solution was discussed.