Tea-leaves based nitrogen-doped porous carbons for high-performance supercapacitors electrode
- 460 Downloads
Nitrogen-doped porous activated carbons have been fabricated through a simple and efficient carbonization method at 700 °C with the waste tea-leaves as carbon precursor and ZnCl2 as activating agent. The average pore size and specific surface area are in the ranges of 2.3–6.6 nm and 10.3 ~ 1143.9 m2 g−1, with the ZnCl2 to tea-leaves weight ratio from 0 to 3. As an electrode material for supercapacitors, the TPACs-2 (the ZnCl2 to tea-leaves weight ratio is 2) which has 3.0 wt% nitrogen content, possesses a large specific capacitance of 296 F g−1 at 0.5 A g−1 and excellent rate capability (74 % retention at 10 A g−1) in 2 mol L−1 KOH. Furthermore, the symmetric supercapacitor fabricated with TPACs-2 electrodes delivers a high energy density of 13.5 Wh kg−1 at a power density of 221 W kg−1 and superior cycle stability (only 9 % loss after 5000 cycles), operating in the wide voltage range of 0–1.8 V in 0.5 mol L−1 Na2SO4 aqueous electrolyte. The results demonstrate TPACs-2 is a promising candidate for the electrode material of supercapacitors.
KeywordsActivated carbon Tea-leaves Nitrogen-doped Chemical activation Supercapacitor
This research was financially supported by the National Science Foundation of China (51462032), the program for Changjiang Scholars and Innovative Research Team in University (IRT15R56), the China Postdoctoral Science Foundation (2013 M540778), Key Laboratory of Eco-Environment-Related Polymer Materials (Northwest Normal University) of Ministry of Education, and Key Laboratory of Polymer Materials of Gansu Province.
- 3.Zhang SL, Pan N (2015) Supercapacitors performance evaluation. Adv Energy Mater 5:1–19Google Scholar
- 6.Yan J, Wang Q, Wei T, Fan ZJ (2014) Recent advances in design and fabrication of electrochemical supercapacitors with high energy densities. Adv Energy Mater 4:1–43Google Scholar
- 35.Wang Y, Zhang L, Wang H, Wang J, Yu W, Peng B, Yang Z, Chai L (2014) Sustainable synthesis of penicillium-derived highly conductive carbon film as superior binder-free electrode of lithium ion batteries. J Solid State Electrochem 18:3209–3214Google Scholar