Tuesday, 21 June 2016
Riverside Center (Hyatt Regency)
A. Y. Kim (Korea Institute of Science and Technology, Korea University), M. K. Kim, J. Y. Kim (Korea Institute of Science and Technology), I. K. Jin (Chungnam National University), Y. Wen, L. Gu (Chinese Academy of Sciences), H. S. Choi (Chungnam National University), D. Byun (Korea University), and J. K. Lee (Korea Institute of Science and Technology)
Lithium-sulfur (Li-S) battery has the theoretical potential to surpass lithium-ion batteries in terms of capacity and energy density for applications in electric vehicles and hybrid electric vehicles. However several drawbacks prevent it from practical application, such as (1) the low electrical conductivity of both sulfur (5 × 10–3 S cm–1), (2) the large volume expansion (about 80%) during lithiation, (3) the intermediate lithium polysulfides (Li2Sx, 3 ≤ x ≤ 8). During the cycling process, the soluble lithium polysulfides may migrate to the anode side by the “shuttle effect”, resulting in significant irreversible capacity loss and corrosion on the lithium metal anode [1]. Many strategies have been developed to enhance the conductivity of sulfur and suppress the dissolution of polysulfides. The carbon host materials used in Li-S cathodes, despite their excellent electrical and mechanical performances, still demonstrate drawbacks such as rapid capacity fading under cycling and reduced entrapment of polysulfide, leading to decreased rate capability [2]. Therefore, a hybrid design is required for a robust cathode material with high conductivity and low volume change during lithiation-delithiation process.Here, we present ladder-inspired multi-walled carbon nanotubes (MWCNT) filled with tin monoxide (SnO) nanoparticles as a new host material. The MWCNT-SnO/S electrode exhibited excellent electrochemical performance such as stable cycling performance and high rate capability. In situ transmission electron microscopy results indicate that the ladder-inspired MWCNT-SnO host efficiently suppresses volume expansion during lithiation and reduces polysulfide dissolution. Furthermore, the ordered SnO nanoparticles facilitate fast electron and ion transfers during the redox reactions, due to act as connecting links between the walls of MWCNT. This development approach can also be applied to other energy storage devices, including lithium-ion batteries and hybrid supercapacitors.
References
[1] H. Yamin, A. Gorenshtein, J. Penciner, Y. Sternberg, E. Peled, J. Electrochem. Soc. 135 (1988) 1045-1048.
[2] Y. Yang, G. Y. Zheng, Y. Cui, Chem. Soc. Rev. 42 (2013) 3018-3032.
