Monoclinic ZIF-8 Nanosheet-Derived 2D Carbon Nanosheets as Sulfur Immobilizer for High-Performance Lithium Sulfur Batteries

Abstract

2D hierarchically porous carbon (2D-HPC) nanosheets with unique advantages are highly desired as host materials for lithium sulfur (Li-S) batteries and other energy storage devices. Herein, we propose a self-template and organic solvent-free approach to synthesize nanosheets of monoclinic ZIF-8 at room temperature from which 2D-HPC nanosheets (ZIF-8 nanosheets carbon denoted as ZIF-8-NS-C) are derived to be an efficient sulfur immobilizer for Li-S batteries for the first time. The anisotropic nanosheets are believed to relate to the symmetry of the monoclinic structure. The 2D ZIF-8-NS-C nanosheets with embedded hierarchical pores construct an effective conductive network through "plane-to-plane" modes to endow superior electron transfer and fast electrochemical kinetics. Moreover, the nitrogen-rich feature of ZIF-8-NS-C can increase the affinity/interaction of carbon host with lithium polysulfides, favoring the cyclic performance. The sulfur/ZIF-8-NS-C (S/ZIF-8-NS-C) cathode shows a superior rate capability with high capacities of 1226 mA h g at 0.2 C and 785 mA h g at 2 C, and a sustainable cycling stability with a capacity attenuation of 0.12% per cycle at 0.5 C for 300 cycles. The approach proposed here pioneers the controllable design of MOF-based structures to inspire the exploration of more variable MOF-derived porous materials for energy storage applications.

Sulfiphilic Few‐Layered MoSe2 Nanoflakes Decorated rGO as a Highly Efficient Sulfur Host for Lithium‐Sulfur Batteries

“…As comparison, the cells with rGO/S as cathodes are also discussed to more clearly explain the role of MoSe 2 . [47,48] The corresponding rate performances at different current densities from 0.12 C to 2 C are displayed in Figure 4C. MoSe 2 @rGO/S and rGO/S show similar profiles.…”

Structural Engineering of Low‐Dimensional Metal–Organic Frameworks: Synthesis, Properties, and Applications

“…[152,175,[245][246][247] To solve these problems, salt-template confined strategy has been developed by Dong and co-workers, which involves the confined assembly of Co 2+ and 2-methylimidazole in the gaps among the salt microcrystals to form ultrathin ZIF-67 nanosheets, which were served as precursors for porous Co, N co-doped carbon nanosheets. [152,175,[245][246][247] To solve these problems, salt-template confined strategy has been developed by Dong and co-workers, which involves the confined assembly of Co 2+ and 2-methylimidazole in the gaps among the salt microcrystals to form ultrathin ZIF-67 nanosheets, which were served as precursors for porous Co, N co-doped carbon nanosheets.…”

“…[311] It exhibited a specific capacitance of 569 F g −1 at a high current density of 32 A g −1 , which is much higher than that of Co/Ni-MOF powder. [245,248,312] For instance, Chen and co-workers reported a layer-stacked Ni-BDC MOF nanosheet, which was used as cathode for alkaline battery-supercapacitor hybrid devices in a mixed electrolyte of 3 m KOH and 0.1 m K 4 Fe(CN) 6 . [89] In addition, LD MOFs have also acted as versatile precursors for the preparation of carbon-based materials and porous metal oxide/sulfide/selenide-based electrode materials for supercapacitors.…”

Co3O4 nanosheet-built hollow dodecahedrons via a two-step self-templated method and their multifunctional applications

“…He and co-workers [6] synthesized the nanocomposite NiCoP/C nanoboxes with an enhanced electrochemical performance as a catalyst for oxygen evolution reaction (OER). In general, hollow nanostructures are fabricated based on auxiliary template such as polystyrene or carbon colloidal spheres [7][8][9], which includes two processes of material growth on auxiliary template and then the removal of template. Obviously, auxiliary templated method is able to realize size control, while bringing fussy fabrication process and high cost.…”