Binder free three-dimensional sulphur/few-layer graphene foam cathode with enhanced high-rate capability for rechargeable lithium sulphur batteries
Royal Society of Chemistry
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Xi, K., Kidambi, P., Chen, R., Gao, C., Peng, X., Ducati, C., Hofmann, S., & et al. (2014). Binder free three-dimensional sulphur/few-layer graphene foam cathode with enhanced high-rate capability for rechargeable lithium sulphur batteries. Nanoscale, 5746-5753. https://doi.org/10.1039/C4NR00326H
A novel ultra-lightweight three-dimensional (3-D) cathode system for lithium sulphur (Li-S) batteries has been synthesised by loading sulphur on to an interconnected 3-D network of few-layered graphene (FLG) via a sulphur solution infiltration method. A free-standing FLG monolithic network foam was formed as a negative of a Ni metallic foam template by CVD followed by etching away of Ni. The FLG foam offers excellent electrical conductivity, an appropriate hierarchical pore structure for containing the electroactive sulphur and facilitates rapid electron/ion transport. This cathode system does not require any additional binding agents, conductive additives or a separate metallic current collector thus decreasing the weight of the cathode by typically ~20-30 wt%. A Li-S battery with the sulphur/FLG foam cathode shows good electrochemical stability and high rate discharge capacity retention for up to 400 discharge/charge cycles at a high current density of 3200 mA g-1. Even after 400 cycles the capacity decay is only ~0.064% per cycle relative to the early (e.g. the 5th cycle) discharge capacity, while yielding an average columbic efficiency of ~96.2%. Our results indicate the potential suitability of graphene foam for efficient, ultra-light and high-performance batteries.
Kai Xi thanks the Cambridge Overseas Trust. P.R.K. acknowledges funding from the Cambridge Commonwealth Trust. S.H. acknowledges funding from ERC grant InsituNANO (no. 279342), EPSRC under grant GRAPHTED (project reference EP/K016636/1) and Grant EP/H047565/1. This research was partially supported by the EU FP7 Work Programme under grant GRAFOL (project reference 285275). XP and CD acknowledge funding from the ERC under grant number 259619 PHOTO EM.
European Research Council (279342)
European Research Council (259619)
External DOI: https://doi.org/10.1039/C4NR00326H
This record's URL: https://www.repository.cam.ac.uk/handle/1810/246851