Intralayered Ostwald Ripening‐Induced Self‐Catalyzed Growth of CNTs on MXene for Robust Lithium–Sulfur Batteries

Abstract

The distinguishable physicochemical properties of MXenes render them attractive in electrochemical energy storage. However, the strong tendency to self‐restack owing to the van der Waals interactions between the MXene layers incurs a massive decrease in surface area and blocking of ions transfer and electrolytes penetration. Here, in situ generated Ti3C2Tx MXene‐carbon nanotubes (Ti3C2Tx‐CNTs) hybrids are reported via low‐temperature self‐catalyzing growth of CNTs on Ti3C2Tx nanosheets without the addition of any catalyst precursors. With combined spectroscopic studies and theoretical calculation results, it is certified that the intralayered Ostwald ripening‐induced Ti3C2Tx nanomesh structure contributes to the uniform precipitation of ultrafine metal Ti catalysts on Ti3C2Tx, thus giving rise to the in situ CNTs formation on the surface of Ti3C2Tx with high integrity. Taking advantages of intimate electrolyte penetration, unobstructed 3D Li+/e transport, and rich electroactive sites, the Ti3C2Tx‐CNTs hybrids are confirmed to be ideal 3D scaffolds for accommodating sulfur and regulating the polysulfides conversion for high‐loaded lithium–sulfur batteries.

A bifunctional VS2–Ti3C2 heterostructure electrocatalyst for boosting polysulfide redox in high performance lithium–sulfur batteries

“…8c and Table S3 † exhibit the most critical parameters for the comparison of carbon-based and heterostructure materials as cathode hosts of LSBs. 56,[63][64][65][66][67][68][69][70][71][72][73][74][75][76][77][78][79][80][81][82] Note that the introduction of the VS 2 -Ti 3 C 2 host results in higher capacity and the lower capacity decay rate per cycle. This result indicates that VS 2 -Ti 3 C 2 /S electrodes have great advantages to assist LSBs to achieve practical applications.…”

MXene/Carbon Nanotube Hybrids: Synthesis, Structures, Properties, and Applications

“…The growth of CNTs was catalyzed by Ti metal NPs derived from Ti 3 C 2 T x . [89] As shown in Figure 3i, the synthesized CNTs were rooted on the surface of MXenes, creating a 3D interconnected percolation network due to the seamless junctions formed between Ti 3 C 2 T x and CNTs. [89] In summary, MXene/CNT hybrids can be prepared by both physical and chemical processes.…”

“…[89] As shown in Figure 3i, the synthesized CNTs were rooted on the surface of MXenes, creating a 3D interconnected percolation network due to the seamless junctions formed between Ti 3 C 2 T x and CNTs. [89] In summary, MXene/CNT hybrids can be prepared by both physical and chemical processes. The driving force in a typical physical procedure includes mechanical turbulence, electrostatic force, hydrogen bonding, and π-π interaction while the chemical bonding between MXenes and CNTs is realized by various material-loading strategies (either ex-situ deposition or in-situ formation of metal catalysts and carbon sources) and different power sources (e. g., microwave irradiation).…”

“…Specific capacity, rate capability, and cycling stability are the most popular parameters used to characterize the performance of a battery, as shown in Table 7. 614 at 1675 mA g À 1 after 600 cycles [191] LiÀ S Ti 3 C 2 T x /MWCNT separator modifier 840 at 167.5 mA g À 1 640 at 3.35 A g À 1 640 at 1675 mA g À 1 after 200 cycles [160] LiÀ S Ti 3 C 2 T x /CNT cathode host 1215 at 335 mA g À 1 765 at 1.68 A g À 1 900 at 1675 mA g À 1 after 840 cycles [85] LiÀ S Ti 3 C 2 T x /CNT cathode host; electrocatalyst 1451 at 335 mA g À 1 686 at 13.4 A g À 1 610 at 1675 mA g À 1 after 500 cycles [138] LiÀ S Ti 3 C 2 T x /MWCNT cathode host 1052 at 335 mA g À 1 164 at 25.1 A g À 1 621 at 1675 mA g À 1 after 500 cycles [89] LiÀ S Ti 3 C 2 T x /CNT cathode host 898 at 837.5 mA g À 1 668 at 3.35 A g À 1 685 at 837.5 mA g À 1 after 600 cycles [121] LiÀ S Ti 3 C 2 T x /MWCNT cathode host 927 at 1675 mA g À 1 640.5 at 6.7 A g À 1 775 at 1675 mA g À 1 after 1000 cycles…”

Low concentration electrolyte with non-solvating cosolvent enabling high-voltage lithium metal batteries

“…Lithium-ion batteries (LIBs) has gradually approached their ceiling of energy density afforded by intercalation chemistry, falling behind the increasing demands for advanced portable electronics and electric vehicles ( Duffner et al., 2021 ). In this context, lithium metal batteries (LMBs) outperform other candidates in terms of energy density because metallic Li anode possesses the highest theoretical specific capacity (3860 mAh g −1 ) and lowest redox potential (−3.04 V vs. the standard hydrogen electrode) ( Wu et al, 2020b ; Xu et al, 2021a ; Zhong et al, 2021 ). Besides, further increasing the working voltage of LMBs is also critical for higher energy density.…”