Applied Surface Science, Vol.481, 473-483, 2019
Sulfur and nitrogen dual-doped porous carbon nanosheet anode for sodium ion storage with a self-template and self-porogen method
The porous carbon nanosheets (as thin as 8 nm) doped with sulfur and nitrogen have been synthesized by directly carbonizing laminaria japonica with a self-template and self-porogen method. Laminaria japonica contains plenty of sodium chloride and potassium compounds, which can be a natural template and the natural porogen, respectively. The obtained carbons possess a three-dimensional connected nanosheet structure with a large specific surface area of 1900 m(2) g(-1), a total pore volume of 1.04 cm(3) g(-1), a pore size distribution centering mainly at around 1.4 nm and 2.7 nm, a S-content of 9.12% and a N-content of 4.52%. Used as sodium-ion battery anode, the optimized sample exhibits an excellent rate performance (210 mA h g(-1) at 1 A g(-1) and 120 mA h g(-1) at 5 A g(-1)) with a good initial coulombic efficiency of 51.5% and specific capacity of 214 mA h g(-1) after 300 cycles at 100 mA g(-1).