Heteroatom-doped porous carbon microspheres derived from ionic liquid-lignin solution for high performance
Chao Liu1, Yi Hou2, Youming Li2
1International Innovation Center for Forest Chemicals and Materials and Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing 210037, China; State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640, China.
Abstract:
In this work, nitrogen and phosphorus dual-doped alkali lignin-based carbon microspheres (MLCM) were prepared by pre-oxidation and carbonization of ionic liquid ([Mmim]DMP) -lignin solution and used as green-based supercapacitor electrode materials. Compared with the directly carbonized alkali lignin carbon (LC), MLCM had a spherical structure with higher specific surface area (938.1 m2/g) and pore volume (0.64 cm3/g). Moreover, MLCM materials showed superior electrochemical performance. In the 1 mol/L H2SO4 electrolyte system, MLCM presented the highest specific capacitance of 338.2F/g at a current density of 0.8 A/g. Furthermore, MLCM was used as a positive and negative electrode material to assemble a symmetrical supercapacitor. The resultant device maintained excellent cycle stability after 5000 times of charging and discharging process at 2 A/g. Overall, the facile, green and sustainable synthesis strategy of heteroatom-doped porous carbon microspheres developed in this work opens a new avenue for the fabrication of high-performance carbon electrode materials, especially based on abundant and renewable lignin.
