Porous carbon electrode for Li-air battery fabricated from solvent expansion during supercritical drying

• Published in: The Journal of supercritical fluids 2018-03, Vol.133, p.77-85
• Main Authors: Kunanusont, Nattanai, Shimoyama, Yusuke
• Format: Article
• Language: English
• Subjects: Li-air battery; Porosity; Porous carbon electrode; Supercritical drying
• ISSN: 0896-8446; 1872-8162
• DOI: 10.1016/j.supflu.2017.09.030

[Display omitted] •Supercritical CO2 drying was applied for fabrication of porous carbon electrode.•Porous carbon electrode from supercritical drying has porosity over than 90%.•Specific electric capacity on Li-air batter with increment of the porosity. Acetylene carbon black and polyvinylidene fluoride (PVDF) based porous electrodes were fabricated from supercritical carbon dioxide drying method at 10.0–20.0MPa and 40°C. Their morphologies, porosities and electrical properties were investigated and compared with the electrodes fabricated from a conventional solvent evaporation. Additionally, those electrodes were practically applied in Li-air battery and tested on the discharge-charge profile for more than 3 cycles. The results show that the porous carbon electrode from supercritical drying has the porosities higher than 90% which is 1.6 times higher than those from the solvent evaporation. Moreover, the supercritical drying pressure affects the porosities and conductivities of the porous carbon electrodes which considered from the mass transfer on the drying and crystallinity variation of PVDF. In the Li-air battery test, it was found the specific electric capacity at the first cycle increases with increment of the porosity.