Abstract
Abstract A novel porous N-doped carbon microsphere (polymer-dopamine derived carbon, PDA-C) with high specific surface area was synthesized as sulfur host for high performance of lithium-sulfur batteries. We used KOH to adjust the pore size and surface area of the PDA-C materials, and then impregnated sulfur into the PDA-C samples by vapor-melting diffusion method. Effects of pore size of the PDA-C samples on the electrochemical performance of the PDA-C@sulfur cathodes were systematically investigated. Raman spectra indicated an enhanced trend of the degree of graphitization of the PDA-C samples with increasing calcination temperature. The surface area of the PDA-C samples increases with amount of the KOH in the pore-creating process. The graphitized porous N-doped carbon provides the high electronic conductive network. Meanwhile, the PDA-C with high surface area and uniform micropores ensures a high interaction toward sulfur as well as the high dispersion of nanoscale sulfur layer on it. The microporous PDA-C@S cathode material exhibits the excellent high rate discharge capability (636 mA h g-1 at 2.0 C) and good low/high-rate cycling stability (893 mA h g-1 (0.5 C) and 608 mA h g-1 (2.0 C) over 100 and 300 cycles). Cyclic voltammogram curves and electrochemical impedance plots show that both the impedance and polarization of the cells increase with decreasing pore size.
Original language | English |
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Article number | 24963 |
Pages (from-to) | 282-289 |
Number of pages | 8 |
Journal | Electrochimica Acta |
Volume | 173 |
DOIs | |
Publication status | Published - 10 Aug 2015 |
Externally published | Yes |
Keywords
- Lithium-sulfur battery
- N-doped carbon
- pore size
- sulfur adsorption
ASJC Scopus subject areas
- General Chemical Engineering
- Electrochemistry