Scalable Approach To Construct Free-Standing and Flexible Carbon Networks for Lithium–Sulfur Battery

Abstract

Reconstructing carbon nanomaterials (e.g., fullerene, carbon nanotubes (CNTs), and graphene) to multidimensional networks with hierarchical structure is a critical step in exploring their applications. Herein, a sacrificial template method by casting strategy is developed to prepare highly flexible and free-standing carbon film consisting of CNTs, graphene, or both. The scalable size, ultralight and binder-free characteristics, as well as the tunable process/property are promising for their large-scale applications, such as utilizing as interlayers in lithium-sulfur battery. The capability of holding polysulfides (i.e., suppressing the sulfur diffusion) for the networks made from CNTs, graphene, or their mixture is pronounced, among which CNTs are the best. The diffusion process of polysulfides can be visualized in a specially designed glass tube battery. X-ray photoelectron spectroscopy analysis of discharged electrodes was performed to characterize the species in electrodes. A detailed analysis of lithium diffusion constant, electrochemical impedance, and elementary distribution of sulfur in electrodes has been performed to further illustrate the differences of different carbon interlayers for Li-S batteries. The proposed simple and enlargeable production of carbon-based networks may facilitate their applications in battery industry even as a flexible cathode directly. The versatile and reconstructive strategy is extendable to prepare other flexible films and/or membranes for wider applications.

Enhanced Cycling Performance for Lithium–Sulfur Batteries by a Laminated 2D g‐C3N4/Graphene Cathode Interlayer

“…in which n is the number of electrons per reaction species (here n is 2f or the reaction of S 8 to Li 2 S 6 or Li 2 S 4 to Li 2 S 2 ), A is the contact area between the electrode and electrolyte (here A is estimated to be the surfacea rea of the electrode, 1.13 cm 2 ), and C Li is the bulk Li + concentration in the electrode (0.54 mmolcm À3 for sulfur [38] ). Figure 3d and Figure S6 c, Supporting Information, shows the plots of I p as af unction of u 1/2 for the two cathodes.…”

In Situ Formed Protective Barrier Enabled by Sulfur@Titanium Carbide (MXene) Ink for Achieving High‐Capacity, Long Lifetime Li‐S Batteries

“…The 50% S@Ti 3 C 2 T x electrode displays even higher capacities (1350 mAh g −1 at 0.1 C) and better rate capability (86% capacity retention as increasing the C‐rate by 20‐fold) compared to the 70% S@Ti 3 C 2 T x electrode. It is noteworthy that our S@Ti 3 C 2 T x electrodes have greatly exceeded the capacities of other reported systems at various C‐rates, such as graphene nanoscrolls,58 graphene paper,59 carbon nanotubes (CNT),60 or their composites48 (Figure S12, Supporting Information). Although reduced graphene oxide‐S freestanding paper exhibited quite similar capacities and rate handling to our 70% S@Ti 3 C 2 T x , we note that their performance was achieved at a lower S loading (60%) 52…”

Metal–Organic Coordination Strategy for Obtaining Metal‐Decorated Mo‐Based Complexes: Multi‐dimensional Structural Evolution and High‐Rate Lithium‐Ion Battery Applications

“…[41,46,47] Based on the analysis, several results can be summarized:i )85.3 %o ft he total capacity is identified as the capacitive contribution from the nanopetals, whichi sm uch highert han the values of 72.2 %a nd 58.1 %f or the multilayers and microflowers,r espectively;i i) the capacitive contribution accountsf or more of the total capacity with increasing the scan rate (Figure 7b,c ). [41,46,47] Based on the analysis, several results can be summarized:i )85.3 %o ft he total capacity is identified as the capacitive contribution from the nanopetals, whichi sm uch highert han the values of 72.2 %a nd 58.1 %f or the multilayers and microflowers,r espectively;i i) the capacitive contribution accountsf or more of the total capacity with increasing the scan rate (Figure 7b,c ).…”