High sulfur loading and shuttle inhibition of advanced sulfur cathode enabled by graphene network skin and N, P, F-doped mesoporous carbon interfaces for ultra-stable lithium sulfur battery

Abstract

Achieving high loading of active sulfur yet rational regulating the shuttle effect of lithium polysulfide (LiPS) is of great significance in pursuit of high-performance lithium-sulfur (Li-S) battery. Herein, we develop a free-standing graphenenitrogen (N), phosphorus (P) and fluorine (F) co-doped mesoporous carbon-sulfur (G-NPFMC-S) film, which was used as a binder-free cathode in Li-S battery. The developed mesoporous carbon (MC) achieved a high specific surface area of 921 m 2 •g -1 with a uniform pore size distribution of 15 nm. The inserted graphene network inside G-NPFMC-S cathode can effectively improve its electrical conductivity and simultaneously restrict the shuttle of LiPS. A high sulfur loading of 86% was achieved due to the excellent porous structures of graphene-NPFMC (G-NPFMC) composite. When implemented as a freestanding cathode in Li-S battery, this G-NPFMC-S achieved a high specific capacity (1,356 mAh•g -1 ), favorable rate capability, and long-term cycling stability up to 500 cycles with a minimum capacity fading rate of 0.025% per cycle, outperforming the corresponding performances of NPFMC-sulfur (NPFMC-S) and MC-sulfur (MC-S). These promising results can be ascribed to the featured structures that formed inside G-NPFMC-S film, as that highly porous NPFMC can provide sufficient storage space for the loading of sulfur, while, the N,P,F-doped carbonic interface and the inserted graphene network help hinder the shuttle of LiPS via chemical adsorption and physical barrier effect. This proposed unique structure can provide a bright prospect in that high mass loading of active sulfur and restriction the shuttle of LiPS can be simultaneously achieved for Li-S battery.

Asymmetrically Coordinated Cu–N1C2 Single‐Atom Catalyst Immobilized on Ti3C2Tx MXene as Separator Coating for Lithium–Sulfur Batteries

“…The electrochemical impedance spectra (EIS) (Figure S45, Supporting Information) were obtained to show that the cells using Cu SA/N-Ti 3 C 2 T x /PP had the lowest interface impedance, which would be beneficial to ions/electrons transport. [10,73,74] Furthermore, the ability of Cu SA/N-Ti 3 C 2 T x to promote lithium ion transport was studied by variable CV curves at different scanning rates (Figure S46, Supporting Information). It could be seen that the cell with Cu SA/N-Ti 3 C 2 T x /PP showed enhanced D Li+ at peak 1 (3.7 × 10 −8 cm 2 s −1 ), peak 2 (5.2 × 10 −8 cm 2 s −1 ), and peak 3 (5.6 × 10 −8 cm 2 s −1 ), which meant that the single-atom coordination structure of Cu enhanced the transport of lithium ions.…”

Defect-Rich W/Mo-Doped V2O5 Microspheres as a Catalytic Host To Boost Sulfur Redox Kinetics for Lithium–Sulfur Batteries

“…Over the past few decades, many solutions have been used to deal with these encouraging limitations, and there have been great breakthroughs in the electrochemical performance of Li–S batteries. − Initially, carbon materials were broadly used in Li–S batteries owing to their adjustable structure and good electrical conductivity. − However, nonpolar carbon materials have very limited restrictions with LiPSs, which leads to severe capacity degradation especially under high sulfur loadings. − For this, some polar materials have been employed as sulfur hosts in Li–S batteries for their strong chemisorption ability to LiPSs, such as metal oxides (Nb 2 O 5 and Fe 3 O 4 ), , sulfur oxides (Ce 2 O 2 S), metal sulfides (Co 9 S 8 , V 5 S 8 , and WS 2 ), ,, metal selenides (CoSe 2 and NiSe 2 ), , metal nitrides (TiN/TiC), and metal phosphides (FeP and NiCoP). , Typically, these metal compounds exhibit a very unique affinity to LiPSs by forming metal–sulfur bonds and have a remarkable effect in limiting the shuttle effect and accelerating the mutual conversion of LiPSs. , Moreover, defect engineering is essential to enhance the catalytic activity of these polar hosts for sulfur redox kinetics in both reversible discharge and charge processes of Li–S batteries. Particularly, introducing defects by anion or cation doping is significant for improving the electrocatalytic performance of the oxide catalysts. , For example, Wang and his colleagues reported that Fe-doped Co 3 O 4 microspheres showed abundant oxygen-rich defects, which provided much catalytic sites for LiPS capture and redox reactions …”

Recent advances in supramolecular self-assembly derived materials for high-performance supercapacitors

“…Doping heteroatoms into carbon materials can introduce extra pseudocapacitive active sites, which can signicantly improve the specic capacitance of carbon-based materials. [27][28][29][30][31] Conductive polymers or metal oxides can also be combined with high electrical conductivity carbon materials to achieve the purpose of complementary advantages. [32][33][34] The common methods such as the hydrothermal method, electrodeposition, co-precipitation and sol-gel method used in the preparation of heteroatom doped carbon and composite materials can improve the conductivity and increase the active sites to a certain extent.…”