Porous Hollow Carbon Aerogel-Assembled Core@Polypyrrole Nanoparticle Shell as an Efficient Sulfur Host through a Tunable Molecular Self-Assembly Method for Rechargeable Lithium/Sulfur Batteries

Abstract

Lithium−sulfur (Li−S) batteries are fascinating as next-generation high specific energy density storation devices. Herein, we report the fabrication of a three-dimensional porous hollow core@shell structure composed of a carbon aerogel assembled core etched via nano-CaCO 3 and a polypyrrole nanoparticle shell as a sulfur scaffold for Li−S batteries. The asprepared sulfur cathodes exhibit excellent reversible capacity (1031.9 mAh g −1 at 0.1 C), outstanding rate capability (566.5 and 477.2 mAh g −1 at 1 and 2 C, respectively), and superior cycling stability (74.2% capacity retention rate at 1 C). The improved electrochemical performance can be attributed to the extraordinary core−shell structure: the honeycomb-like carbon aerogel core provides fast transportation for the Li + /e − , and even sufficient free space for the volume expansion; the polypyrrole nanoparticle shell acts not only as a physical obstacle but also as a polar material to restrict the shuttling of polysulfides by chemical interaction. These inspiring results specify that such electrodes could empower high performance, fast charging, and flexible Li−S batteries through a tunable molecular self-assembly method to clad strong polar material on carbon materials.

Polypyrrole/Graphene Composite Interlayer: High Redox Kinetics of Polysulfides and Electrochemical Performance of Lithium–Sulfur Batteries Enabled by Unique Pyrrolic Nitrogen Sites

“…PPy/G delivers a pore volume of 1.85 cm 3 g À 1 owns micropores (< 2 nm) and mesopores (2-50 nm), higher than those of G (1.68 cm 3 g À 1 ), which favor of electrolyte infiltration. [24] As shown in Figure 2d, the contact angle of electrolyte on PPy/G interlayer is 15°, which is much smaller than that of PP (43°), indicating enhanced wettability of the separator by PPy/G interlayer. Therefore, PPy/G interlayer is conducive to the penetration of electrolyte, redox reaction of the dissolved PSs in electrolyte and reutilization of sulfur content, which is beneficial to the suppression of the shuttle effect and the improvement of electrochemical performance.…”

“…The porous properties of G and PPy/G were explored by N 2 adsorption/desorption (Figure S2). PPy/G delivers a pore volume of 1.85 cm 3 g −1 owns micropores (<2 nm) and mesopores (2–50 nm), higher than those of G (1.68 cm 3 g −1 ), which favor of electrolyte infiltration [24] …”

“…However, non-polar carbon nanomaterials show weak chemical affinity to PSs and poor electrolyte wettability, and drive slow lithium-ion transfer and redox kinetics of PSs, thus the electrochemical performance, especially the rate capability and the cycling performance of the LiÀ S batteries remains unsatisfactory. [19] Therefore, carbon materials are generally modified by doping hetero-atoms and polymer, [17,18,[20][21][22][23][24] which enhance the adsorption of PSs, the electronic conductivity of carbon matrix and the redox kinetics of sulfur species.…”

MOF-derived multifunctional filler reinforced polymer electrolyte for solid-state lithium batteries

“…Lithium ion batteries (LIBs) have been widely used as power sources in mobile electronic equipment and large energy storage systems [1][2][3][4][5]. However, the electrolytes used in current LIBs are mainly combustible organic compounds, so there are serious safety risks.…”

Multifunctional MOF‐Based Separator Materials for Advanced Lithium–Sulfur Batteries

“…The use of carbon aerogel as a sulfur electrode material has been proven to be an effective method for constructing high-performance LSBs. [45][46][47][48] In addition to the improvement of the sulfur positive electrode, researchers are also exploring metal lithium in the negative electrode. It has been reported that the use of micro-nano lithium metal as a negative electrode can not only curb the formation of lithium dendrites but also control the process of lithium plating and stripping.…”