Electrochemical Behavior of Ti 3 C 2 T x MXene in Environmentally Friendly Methanesulfonic Acid Electrolyte

Chen

et al. 2020

Adv Funct Materials

Self Cite

120

MXenes derived from 413 MAX phases are rarely studied but they have the potential to have superior electrical and mechanical properties thanks to a thicker monolayer (four layers of transition metal and three layers of carbon or nitrogen). In this paper, Nb 4 C 3 T x MXene nanosheets are delaminated and freestanding film with 1.77 nm interlayer spacing is obtained, which is larger than that of most previous MXenes. When Nb 4 C 3 T x freestanding films are tested as supercapacitors electrodes, Nb 4 C 3 T x shows high volumetric capacitance, 1075, 687, and 506 F cm −3 in 1 m H 2 SO 4 , 1 m KOH, and 1 m MgSO 4 , respectively, at the scan rate of 5 mV s −1. An in situ X-ray diffraction technique is used to study the structural changes during the electrochemical charging in 1 m H 2 SO 4 and 1 m MgSO 4. There is almost no change in the 21 Å interlayer spacing during the cycling, because the space between the MXene layers is sufficient to accommodate the insertion and deinsertion of cations. This can lead to stable performance of Nb 4 C 3 T x MXene energy storage devices.

“…This mechanism is different from Ti 3 C 2 T x , where the smaller interlayer distance is observed to change during each cycle of surface protonation/deprotonation. [42,43]…”

Section: Resultsmentioning

confidence: 99%

Flexible Nb₄C₃T_x Film with Large Interlayer Spacing for High‐Performance Supercapacitors

Chen

et al. 2020

Adv Funct Materials

Self Cite

120

“…The aforementioned results visually reveal that the as-prepared Cr 2 GeC nanoparticle can facilitate fast and stable lithium storage. Table 1 shows the comparison of the lithium-storage performance of the synthesized Cr 2 GeC and other reported MAX phase materials (Xu et al, 2016;Chen et al, 2018;Luan et al, 2019;Zhao et al, 2019;Li et al, 2021). It can be seen that the as-prepared Cr 2 GeC also presents promising lithium-storage performance.…”

Section: Resultsmentioning

confidence: 96%

“…Energy storage materials have been continuously investigated to support the development of highperformance LIBs. MAX phases with special laminated structures and excellent metal conductivities have been considered as potential lithium-storage hosts (Xu et al, 2016;Chen et al, 2018;Luan et al, 2019;Zhao et al, 2019). Xu et al investigated the reversible electrochemical intercalation behavior of Li ions in Ti 2 SC and Ti 3 SiC 2 MAX phases and concluded that particle size has an important influence on the electrochemical properties of MAX phases.…”

Section: Introductionmentioning

confidence: 99%

Molten salt electrosynthesis of Cr2GeC nanoparticles as anode materials for lithium-ion batteries

et al. 2023

The two-dimensional MAX phases with compositional diversity are promising functional materials for electrochemical energy storage. Herein, we report the facile preparation of the Cr2GeC MAX phase from oxides/C precursors by the molten salt electrolysis method at a moderate temperature of 700°C. The electrosynthesis mechanism has been systematically investigated, and the results show that the synthesis of the Cr2GeC MAX phase involves electro-separation and in situ alloying processes. The as-prepared Cr2GeC MAX phase with a typical layered structure shows the uniform morphology of nanoparticles. As a proof of concept, Cr2GeC nanoparticles are investigated as anode materials for lithium-ion batteries, which deliver a good capacity of 177.4 mAh g−1 at 0.2 C and excellent cycling performance. The lithium-storage mechanism of the Cr2GeC MAX phase has been discussed based on density functional theory (DFT) calculations. This study may provide important support and complement to the tailored electrosynthesis of MAX phases toward high-performance energy storage applications.

“…Together with neutral aqueous electrolytes, acid aqueous electrolytes can provide the changes in interlayer spacing and/ or electrochemical displacement of MXene. [45][46][47] Pang et al demonstrated the electrochemical actuation of MXene with both 1 M H 2 SO 4 liquid and H 2 SO 4 /PVA gel electrolytes in three-and two-electrode cell configurations, respectively. [45] The changes in curvature and strain of MXene were clearly shown as a function of scan rates and frequency at maximum voltage in both MXenebased cells with 1 M H 2 SO 4 (0.083 mm À1 and 0.29%) or H 2 SO 4 / PVA electrolytes (0.038 mm À1 and 0.26%).…”

Section: Aqueous Electrolytesmentioning

confidence: 99%

Recent Progress in MXene‐Based Electrochemical Actuators and Capacitors

Park,

Kim,

Bark

et al. 2024

Small Structures

A new family of two‐dimensional (2D) transition metal carbides, carbonitrides, and nitrides (MXenes) has attracted increasing attention owing to their electrical, chemical, and physical properties. Together with various attractive properties of the MXenes, they also exhibit electrochemical induced deformation (i.e., expansion/contraction) via ion intercalation/de‐intercalation in/from MXene layers. In this respect, MXenes offer the possibility of application as the electrode of electrochemical actuators (ECAs). While the MXene‐based ECAs are still in their infancy stage, researchers have made great effort to achieve high‐performance MXene‐based electrochemical capacitors (ECs). As the name suggests, both ECAs and ECs shared common traits in which their operations are based on electrochemical processes. This review provides the recent progress in the MXene‐based ECAs in parallel with that in the MXene‐based ECs to gain insights from the relatively mature developments in EC applications. Finally, based on the findings from previous studies on both electrochemical applications, perspectives on future MXene‐based ECAs in terms of electrode, electrolyte, and cell configuration are provided.