biostudies-literatureZhou GState Key Laboratory of Coordination ChemistryNational Natural Science Foundation of ChinaChina Postdoctoral Science FoundationQinglan Project of Jiangsu Province of ChinaNatural Science Foundation of Jiangsu Province3246-3255https://www.ebi.ac.uk/biostudies/studies/S-EPMC9048626biostudies-literatureUnknown10(6)Biomass porous carbon materials are ideal supercapacitor electrode materials due to their low price, rich source of raw materials and environmental friendliness. In this study, an ultrasonic-assisted method was applied to synthesize the rice-straw-based porous carbon (UPC). The obtained UPC exhibited a two-dimensional structure and high specific surface area. In addition, the electrochemical test results showed that the UPC with a 1 hour ultrasonic treatment and lower activation temperature of 600 °C (UPC-600) demonstrated optimal performance: high specific capacitances of 420 F g^-1 at 1.0 A g^-1 and 314 F g^-1 at a high current of 10 A g^-1. Significantly, the symmetric supercapacitors showed a high energy density of 11.1 W h kg^-1 and poRSC advancesAn ultrasonic-assisted synthesis of rice-straw-based porous carbon with high performance symmetric supercapacitors.PMC9048626BK201224151872109, 212010722013T60517SKLCC1916Zhao PZhu FZhou GGao XLi RSun ZXu JYin JfalseAn ultrasonic-assisted synthesis of rice-straw-based porous carbon with high performance symmetric supercapacitors.Biomass porous carbon materials are ideal supercapacitor electrode materials due to their low price, rich source of raw materials and environmental friendliness. In this study, an ultrasonic-assisted method was applied to synthesize the rice-straw-based porous carbon (UPC). The obtained UPC exhibited a two-dimensional structure and high specific surface area. In addition, the electrochemical test results showed that the UPC with a 1 hour ultrasonic treatment and lower activation temperature of 600 °C (UPC-600) demonstrated optimal performance: high specific capacitances of 420 F g^-1 at 1.0 A g^-1 and 314 F g^-1 at a high current of 10 A g^-1. Significantly, the symmetric supercapacitors showed a high energy density of 11.1 W h kg^-1 and po2020-01-01T00:00:00Z2020 Jan2025-04-04T08:36:42.23Z2025-02-18T23:22:14.163ZS-EPMC90486263549772210.1039/c9ra08537h