Organosilica-based ionogel derived nitrogen-doped microporous carbons for high performance supercapacitor electrodesElectronic supplementary information (ESI) available. See DOI: 10.1039/c8qi01034j

• Main Authors: Wang, Peng, Tao, Lumi, Luo, Huan, Chen, Dongyang, Xie, Zailai
• Format: Journal Article
• Published: 04.12.2018
• DOI: 10.1039/c8qi01034j

The article presents the synthesis and properties of new organosilica-based ionogels for carbon precursors. A new preparation process using functional ionic liquid 1-propionic acid-2-methyl imidazole bromide as the linker and an organically modified silica framework as the host yields stable, yellowish and transparent organosilica ionogels. The ionogel is formed by (1) the sol-gel process of an organosilane [3-(2-aminoethylamino)propyl]trimethoxysilane and (2) the covalent interaction of a carboxyl-functional group of the ionic liquid with the amino-containing organosilica. Furthermore, controllable synthesis of nitrogen-doped microporous carbons from the direct pyrolysis of organosilica-based ionogels is reported. The ionic liquid serves as carbon and nitrogen sources, while the organically modified silica framework acts as an inherent template to induce porosity. As a result, high surface areas of up to 1107 m 2 g −1 and high nitrogen contents of up to 3.9 wt% are achieved. The electrode prepared from C-1000 delivers a remarkable capacity of 254 F g −1 at a current density of 1 A g −1 , which can be attributed to the synergistic coupling effect of N-doping, hierarchical porosity and intrinsic defects. A new preparation process is developed to yield stable, yellowish and transparent organosilica ionogels, which after pyrolysis yields N-doped microporous carbon with remarkable capacity.