TiO 2 coated three-dimensional hierarchically ordered porous sulfur electrode for the lithium/sulfur rechargeable batteries

Abstract

Guo, Z. (2014). TiO2 coated three-dimensional hierarchically ordered porous sulfur electrode for the lithium/sulfur rechargeable batteries. Energy, 75 597-602.TiO2 coated three-dimensional hierarchically ordered porous sulfur electrode for the lithium/sulfur rechargeable batteries AbstractA three-dimensional (3D) hierarchically ordered mesoporous carbon-sulfur composite slice coated with a thin TiO2 layer has been synthesized by a low-cost process and investigated as a cathode for the lithium-sulfur batteries. The TiO2 coated carbon sulfur composite thin slice works as a binder-free cathode without any current collectors for lithium-sulfur batteries. The hierarchical architecture provides a 3D conductive network for electron transfer, open channels for ion diffusion and strong confinement of soluble polysulfides. Meanwhile, TiO2 (titanium dioxide) coating layer could further effectively prevent the dissolution of polysulfides and also improve the strength of the entire electrode, thereby enhancing the electrochemical performance. As a result, after TiO2 coating, the electrode demonstrates excellent cycling performance, with a discharge capacity of 608 mAh/g at 0.2 C current rate and 500 mAh/g at 1 C current rate after 120 cycles, respectively. ABSTRACT: A three-dimensional (3D) hierarchically ordered mesoporous carbon-sulfur composite slice coated with a thin TiO 2 layer has been synthesized by a low-cost process and investigated as a cathode for the lithium-sulfur batteries. The TiO 2 coated carbon sulfur composite thin slice works as a binder-free cathode without any current collectors for lithium-sulfur batteries. The hierarchical architecture provides a 3D conductive network for electron transfer, open channels for ion diffusion and strong confinement of soluble polysulfides. Meanwhile, TiO 2 coating layer could further effectively prevent the dissolution of polysulfides and also improve the strength of the entire electrode, thereby enhancing the electrochemical performance. As a result, after TiO 2 coating, the electrode demonstrates excellent cycling performance, with a discharge capacity of 608 mAh/g at 0.2 C current rate and 500 mAh/g at 1 C current rate after 120 cycles, respectively.

Fabrication of polyaniline nanowire/TiO2 nanotube array electrode for supercapacitors

“…Furthermore, vertically oriented TiO 2 nanotube arrays provide a direct pathway for electron transport along the long axis of nanotubes to the substrate [11,12]. TiO 2 enhances the electrocatalytic activity, cycling stability and rate performance [13,14]. However, pristine TiO 2 nanotube arrays generally suffer from poor capacitive behavior, as TiO 2 is a wide bandgap semiconductor with limited conductivity.…”

Three-dimensionally ordered macro-/mesoporous carbon loading sulfur as high-performance cathodes for lithium/sulfur batteries

“…However, they have not been widely employed in practical applications due to their several drawbacks, including the insulating nature of sulfur (5×10 -30 S cm -1 at 25 °C) and the shuttle loss of lithium polysulfides (Li 2 S x , 4≤X≤8) during the cycling process [4]. The problems mentioned above could be addressed by encapsulating sulfur into a conductive matrix to promote electrical conductivity of the sulfur composite and offer a physical confinement of the polysulfides [5][6][7][8][9][10].…”

Fabrication of a new gel polymer electrolyte containing core–shell silica–polyelectrolyte nanoparticles via activators regenerated by electron transfer atom transfer radical polymerization (ARGET-ATRP) for high-performance lithium–sulfur batteries

“…Sulfur has a theoretical specific capacity of 1672 mAhg -1 about 5 times higher than those of traditional cathode materials based on transition metal oxides or phosphates which make lithium-sulfur (Li/S) redox couple a promising candidate for high energy density batteries (Ji et al 2009;Ji et al 2011a, b;Li et al 2013;Wang et al 2014). However, it has been difficult to develop a practical Li/S battery due to the low electrical conductivity of sulfur and dissolution of polysulfides into liquid electrolytes.…”