Multiple Effects of High Surface Area Hollow Nanospheres Assembled by Nickel Cobaltate Nanosheets on Soluble Lithium Polysulfides

Abstract

Inhibiting the shuttle effect of soluble polysulfides and improving slow reaction kinetics are key factors for the future development of Li–S batteries. Herein, edelweiss shaped NiCo2O4 hollow nanospheres with a high surface area were prepared by a simple template method to modify the separator to realize multiple physical constraints and strong chemical anchoring on the polysulfides. On one hand, the good electrolyte wettability of NiCo2O4 promoted the migration of Li-ions and greatly improved the dynamics. On the other hand, mesoporous NiCo2O4 nanomaterials provided many strong chemical binding sites for loading sulfur species. The hollow structure also provided a physical barrier to mitigate the sulfur species diffusion. Therefore, the modified separator realized multiple physical constraints and strong chemical anchoring on sulfur species. As a result, the sulfur cathode based on this composite separator showed significantly enhanced electrochemical performance. Even at 4 C, a high capacity of 505 mAh g−1 was obtained, and about 80.6% could be retained after 300 cycles.

Interfacial Engineering of Ru Nanocluster-Modified TiO2 Nanotube-Assisted Regulation of Lithium Polysulfide Reactions

“…32,33 Interestingly, compared with the TiO 2 @S electrode, the redox peak of the TiO 2 −Ru@S electrode moved toward the quasi-equilibrium potential, which meant that the latter had less dynamic resistance. 34 The corresponding voltage polarization of TiO 2 −Ru@S was ∼0.29 V, lower than that of the TiO 2 @S sample (∼0.34 V). From the illustration of Figure 3b, the Tafel plots of anodic and cathodic peaks in TiO 2 @S were calculated to be 97.8 mV dec −1 (O), 41.6 mV dec −1 (R 1 ) and 62.0 mV dec −1 (R 2 ).…”

“…Two distinct reduction peaks and a wide oxidation peak appeared in the CV curve (Figure a). Typically, the peak at ∼2.3 V (R 1 ) represented the conversion of S 8 to soluble long-chain LiPSs, and the peak at ∼2.0 V (R 2 ) represented the formation of solid short-chain Li 2 S 2 /Li 2 S. The oxidation peak between 2.3–2.4 V (O) meant the opposite anodic reaction process. , Interestingly, compared with the TiO 2 @S electrode, the redox peak of the TiO 2 –Ru@S electrode moved toward the quasi-equilibrium potential, which meant that the latter had less dynamic resistance . The corresponding voltage polarization of TiO 2 –Ru@S was ∼0.29 V, lower than that of the TiO 2 @S sample (∼0.34 V).…”

Polysaccharide-Based Micro/Nanomotors for Active Ingredient Delivery in Food

“…Metal nanoparticles attached to one end of Fe-PMNMs and Pt-PMNMs form an asymmetric structure, which provides the driving force for their movement (Figure c) . Three molecule modification helps to maintain the hollow structure of microtubules, providing more binding sites and space for the loading of active substances . At the same time, the inner and outer surfaces of microtubules can be charged by changing the assembly order of raw materials, so as to combine with other active substances by an electrostatic interaction or hydrophobic interaction …”

“…41 Three molecule modification helps to maintain the hollow structure of microtubules, providing more binding sites and space for the loading of active substances. 42 At the same time, the inner and outer surfaces of microtubules can be charged by changing the assembly order of raw materials, so as to combine with other active substances by an electrostatic interaction or hydrophobic interaction. 18 The functional groups of CS and κ-CG were analyzed by infrared spectroscopy, and the results are shown in Figure 1d.…”