Abstract
A rapid (5-s) sulfur deposition technique is demonstrated on electrospun carbon nanofibers to fabricate binder-free, freestanding cathodes for lithium-sulfur batteries. The 5-second procedure melts sulfur into carbon nanofiber mats, which play a significant role as a built-in conductive matrix to provide uninterrupted electron transport pathways throughout the electrode such that the heavy current collector is eliminated. Meanwhile, the large inter-fiber spacing facilitates electrolyte diffusion and provides sufficient space for sulfur integration during cathode fabrication and the volume expansion during lithium-sulfur redox reaction. This technique eliminates the need for slurry processing with insulating binders and toxic solvents while eliminating heavy current collectors. This ultra-rapid technique involving only 140 °C, 5 s, and slight pressure (<250 psi) offers a practical approach to light-weight sulfur cathodes compared to the conventional sulfur melt deposition techniques requiring high temperatures (155–300 °C), long times (8–10 h), and heavy components in the cell assembly. The cathodes thus obtained deliver a discharge capacity of ∼550 mAh g sulfur −1 owing to their simple construction, with 100% capacity retention at 0.5C rate over 150 cycles. This translates to ∼250 mA h g electrode −1 (based on total mass at the cathode) which is comparable to highly sophisticated electrodes when the weight of the entire electrode and current collector is considered.
Original language | English |
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Pages (from-to) | 336-344 |
Number of pages | 9 |
Journal | Materials Today Energy |
Volume | 9 |
DOIs | |
Publication status | Published - 2018 Sept 1 |
All Science Journal Classification (ASJC) codes
- Renewable Energy, Sustainability and the Environment
- Materials Science (miscellaneous)
- Nuclear Energy and Engineering
- Fuel Technology
- Energy Engineering and Power Technology