Chinese knot-like electrode design for advanced Li-S batteries. (November 2018)

• Record Type: Journal Article
• Authors: Dai, Chunlong; Hu, Linyu; Li, Xinyu; Xu, Qiuju; Wang, Rui; Liu, Heng; Chen, Hao; Bao, Shu-Juan; Chen, Yuming; Henkelman, Graeme; Li, Chang Ming; Xu, Maowen
• Is Part Of: Nano energy. Volume 53(2018)
• Page Start: 354
• Page End: 361
• Publication Date: 2018-11
• Subjects: Chinese knot-like electrode design -- Interwoven -- Lithium-sulfur battery -- Reaction kinetics; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2018.08.065
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: Rational design of Li-S batteries requires efficient prevention of sulfur mobility and fast redox kinetics while accommodating the volumetric expansion of the sulfur cathode. Herein, we propose a multifunctional Chinese knot-like electrode design for advanced Li-S batteries. NiCo2 S4 nanotubes are closely interwoven to form Chinese knot-like designs as a sulfur host. The unique interconnectivity of the 2D Chinese knot-like networks constructed by 1D nanostructured nanotubes enables fast electron transfer for high capacity. Furthermore, the hollow structure can simultaneously provide enough space for volumetric expansion of sulfur and confine lithium polysulfides (LiPSs) in the internal void space by structural encapsulation. Besides these, experimental and theoretical analysis demonstrates that NiCo2 S4 can effectively capture the LiPSs and then catalyze the captured LiPSs into solid Li2 S2 /Li2 S. More importantly, the transition between low-spin and high-spin of Co ions, induced by extra sulfur atoms from LiPSs, provides an electronic way to stabilize the adsorption system and reduce system energy, leading to the inhibition of the shuttle effect in Li-S batteries. As a result, the Chinese knot-like S@NiCo2 S4 electrodes show a high capacity of 1348 mA h g −1 at 0.1 C and long cycling life up to 1000 cycles with a slow capacity decay of 0.02% per cycle at 1 C. Even with a higher sulfur loading of 5 mg cm −2, the electrodes still deliver good electrochemical performance. Graphical abstract: fx1 Highlights: Multifunctional Chinese knot-like designs interwoven by hollow NiCo2 S4 nanotubes has been synthesized as a sulfur host. NiCo2 S4 can effectively capture the LiPSs and then catalyze the captured LiPSs into solid Li2 S2 /Li2 S. he S@NiCo2 S4 electrodes deliver good electrochemical performance at low (2 mg cm -2 ) and high (5 mg cm -2 ) sulfur loadings.