Search

Chemical manipulation of surface functional groups on two‐dimensional transition metal carbides and/or nitrides (MXenes) provides a wide range of design and application prospects. However, achieving rapid targeted modification of surface groups remains a significant challenge. Herein, we propose a general strategy to swiftly shear and customize surface groups on Ti3C2Tx−MXene via the flash Joule heating (FJH) reaction within 1 s. Successfully, MXenes with 9 target terminations, including VII A (F, Cl, Br, or I), VI A (O, S, or Se), and V A (N or P), either single or multiple, are synthesized, with a surface content of up to about 76 %. The impact of these terminations is systematically analyzed on electrochemical performance, demonstrating that VI A and V A terminations have higher electrochemical activity than VII A. Particularly, N‐, S‐, and O‐terminated MXenes exhibit enhanced specific capacities and undecayed cycling performance. These findings offer valuable insights for the surface engineering design and performance optimization of functional materials. [ABSTRACT FROM AUTHOR]

Aqueous zinc‐ion batteries (ZIBs) hold significant promise for large‐scale energy storage. While considerable strides have been made in modifying separators, the challenge of developing dendrite‐free, corrosion‐resistant, and cost‐effective separators for achieving extended cycling performance of Zn anodes persists. In light of this, a TiO2 coating separator to mitigate interfacial corrosion and passivation reactions, thereby facilitating high‐performance ZIBs is designed. This study delves into the influence of the loading amount and crystal phase of the TiO2 coating layers on separator modification. Zn symmetric cells employing the anatase TiO2‐modified glass fiber (A‐TiO2@GF) separator demonstrate superior Zn2+ ion transport kinetics in a mild ZnSO4 electrolyte, ensuring sustained long‐term stability and uniform Zn deposition. Furthermore, the reduced hydrogen evolution reaction (HER) activity of A‐TiO2 coatings curbs H+ ion migration, minimizing interfacial corrosion and HER. Consequently, the assembled Zn||CaV8O20 zinc‐ion full cells demonstrate outstanding long‐term durability and impressive specific capacity, boasting a discharge capacity of 142 mAh g−1 after 1000 cycles. This work introduces a straightforward interface engineering strategy for creating efficient separators in zinc‐ion batteries, promoting uniform Zn deposition. [ABSTRACT FROM AUTHOR]

Aqueous zinc ion batteries (AZIBs) have stimulated extensive attention due to their environmental friendliness and low cost. Unfortunately, the inevitable dendrite growth and corrosion on the zinc (Zn) anode severely hinder the practical application of AZIBs. Herein, an amino acid containing an imidazole group is introduced as an effective additive to address these issues. The dynamic conversion of amino acid and protonated amino acid creates a pH buffer function that regulates solution pH in real time, inhibits hydrogen evolution reaction (HER), and eliminates notorious by‐products. In addition, the protonated amino acid is preferentially adsorbed on the Zn anode, preventing contact of the active water with the Zn surface and promoting homogeneous Zn deposition. Thus, the amino acid‐based electrolyte promotes dendrite free plating/stripping with a Coulombic efficiency up to 99.67% and cycle lifetime of 2600 h. In particular, a depth of discharge of up to 87% can be achieved with an ultra‐high areal capacity of 24 mAh cm−2. The developed Zn||CVO full cell also exhibits better electrochemical performance than that without additives. This work provides an effective and convenient approach for safe and efficient Zn‐ion batteries. [ABSTRACT FROM AUTHOR]

The lack of high‐performance electrodes is a key factor restricting the development of sodium‐ion batteries (SIBs), and usually a certain type of electrode material alone often fails to combine the merits of high capacity and good conductivity. Herein, nitrogen‐doped carbon (NC) was used as a multifunctional bridge to uniformly compound high‐capacity MoS2 nanoparticles with highly conductive Ti3C2Tx nanosheets to form Ti3C2Tx@MoS2/NC composite with flower‐like architecture. Ultrafine MoS2 nanoparticles were uniformly anchored on Ti3C2Tx nanosheets to form nanosheets primary building blocks with a sandwich‐like architecture, which not only shortens the ion transfer distance but also enlarges the layer spacing of Ti3C2Tx favoring the storage of more sodium ions as well as their transport capacity. Moreover, the flower‐like structures with abundant edges can provide an ample active sites and high pseudocapacitance behavior. As a result, flower‐like Ti3C2Tx@MoS2/NC displays a high electrochemical properties with an excellent cycling stability over 2000 cycles (81.4 % capacity retention) and preeminent rate capacity of 383 mAh g−1 at 30 A g−1. Furthermore, Ti3C2Tx@MoS2/NC‖Na3V2(PO4)3 full cell displays a capacity of 59 mAh g−1 at 0.4 A g−1 after 180 cycles. This work displays a high‐performance anode composite for SIBs and provides insight into the preparation of other composites. [ABSTRACT FROM AUTHOR]

The article titled "Enhancing Electrochemical Performance through Swift Functional Group Tuning of MXenes" discusses the use of flash Joule heat (FJH) technology to modify the surface of MXene materials. The researchers demonstrate that this technique can be used to cut and modulate the terminations on the MXene surface within 1 second. The study shows that certain terminations, specifically VI A and V A, outperform VII A terminations in terms of electrochemical performance. For more information, readers can refer to the research article by Y.-Z. Fang, D. Cao, and their colleagues. [Extracted from the article]