Metal–Organic Framework-Derived NiSe₂ Nanoparticles on Graphene for Polysulfide Conversion in Lithium–Sulfur Batteries

Abstract

The rechargeable lithium–sulfur battery is regarded as one of the most promising secondary batteries because of its superior energy density and cost-effective raw materials. However, it still faces many challenges, the most important of which lies in the notorious polysulfide shuttle effect. Herein, we design and fabricate graphene-supported, metal–organic framework (MOF)-derived NiSe2 nanoparticles (rGO-NiSe2) as separator modifiers. The NiSe2 nanoparticles with high catalytic activity can effectively adsorb polysulfides and accelerate their conversion. A highly conductive graphene as a catalyst substrate can effectively decrease the internal resistance of the battery. In addition, the intercalation growth of octahedral MOF-derived NiSe2 nanoparticles between graphene sheets provides abundant active sites for polysulfides. The battery with a rGO-NiSe2-modified separator provides an initial capacity of 1356.5 mAh g–1 at 0.2 C, and only experiences a low capacity decay rate of 0.079% per cycle during 500 cycles of operation at 1 C. Even under a relatively high loading amount of 5.2 mg cm–2, the battery can still yield a high specific capacity of 774.3 mAh g–1 at 0.5 C and a capacity retention of 84% after 100 cycles.

Flexible electrode of Fe-doped NiSe2@porous graphene as binder-free anode for lithium-ion batteries

“…Corresponding satellite peaks are located at 878.6 eV and 860.2 eV. 40–45 However, compared with NiSe 2 @PG, the Ni 2p (including Ni 3+ 2p 1/2 , Ni 2+ 2p 1/2 , Ni 3+ 2p 3/2 , and Ni 2+ 2p 3/2 ) of Fe-NiSe 2 @PG presents upshifts to higher binding energies of about 0.1 eV, indicating that the Fe doping changes the electrical structure of NiSe 2 and increases the binding energy of Ni 2p. 46,47 To further analyze the effect of iron doping on the interfacial interaction between graphene and NiSe 2 , the Se 3d spectra were investigated in detail (Fig.…”

Chevrel Phase Mo6S8 Nanosheets Featuring Reversible Electrochemical Li‐Ion Intercalation as Effective Dynamic‐Phase Promoter for Advanced Lithium‐Sulfur Batteries

“…As shown in Figure 4b,c, a typical charge‐discharge voltage platform is shown, and the corresponding internal reaction resistances were examined. The internal reaction resistance can be quantified according to the following equation: [ 53,54 ] $$\[ \begin{array}{*{20}{c}}{\Delta {R_{{\rm{internal}}}}\;\left( \Omega \right) = \left| {\Delta {V_{{\rm{QOCV}} - {\rm{CCV}}}}} \right|{\rm{/}}{I_{{\rm{applied}}}}}\end{array} \]$$…”

“…As shown in Figure 4b,c, a typical chargedischarge voltage platform is shown, and the corresponding internal reac tion resistances were examined. The internal reaction resistance can be quantified according to the following equation: [53,54]…”

Synergistic design of a semi-hollow core–shell structure and a metal–organic framework-derived Co/Zn selenide coated with MXene for high-performance lithium–sulfur batteries

“…In recent years, an increasing number of researchers have employed metallic selenides possessing high conductivity and polarity for LSBs with cathode sulfur carriers. [20][21][22][23][24] For example, our group recently reported a highly efficient CoSe electrocatalyst with a hierarchical porous nanopolyhedron structure (CS@HPP) derived from zeolitic imidazolate framework-67 (ZIF-67). 25 An effective 'adsorption-diffusion-conversion' of LiPSs was achieved using the sulfur cathode of the CS@HPP structure, resulting in high rate capability and long cycle life of LSBs.…”