Cationic vanadium vacancy-enriched V2−xO5 on V2C MXene as superior bifunctional electrocatalysts for Li-O2 batteries

MoS2@C with S vacancies vertically anchored on V2C-MXene for efficient lithium and sodium storage

“…The weight loss below 200 °C in all samples could be attributed to the volatilization of physically absorbed water. 23,61 For f-V 2 C, the decomposition of surface groups (-OH, -F, -O, etc.) occurred at 200-360 °C, while the weight gain above 360 °C could be assigned to the oxidation of V 2 C-MXene into VO x (eqn (S1) †).…”

“…occurred at 200-360 °C, while the weight gain above 360 °C could be assigned to the oxidation of V 2 C-MXene into VO x (eqn (S1) †). 23,49,52 The weight loss at 200-460 °C in MoS 2 @C could be ascribed to the combustion of carbon to CO 2 and oxidation of MoS 2 into MoO 3 (eqn (S2) and (S3) †), while the peak above 700 °C was related to the sublimation of MoO 3 (eqn (S4) †). 29,36,55 The f-V 2 C-MoS 2 @C underwent weight changes related to the combustion of carbon, oxidation of MoS 2 , and decomposition and oxidation of f-V 2 C at higher temperatures of 220-520 °C, which probably originated from the strong interaction between MoS 2 and V 2 C-MXene.…”

“…16,21,22 Nevertheless, their self-restacking, low specific capacity and unsatisfactory ion accessibility restrict their application in LIBs and SIBs. 21,23,24 Constructing 3D MXenes and/or coupling active electrode materials with MXenes could efficiently suppress the rearrangement of MXenes, provide additional active sites and enhance the conductivity of active electrode materials, and has been considered to be an effective approach to address the above-mentioned energy storage and conversion challenges. [25][26][27][28] Han et al fabricated two carbon-coated Nb 2 CT x -MoS 2 electrodes and found that the highly conductive Nb 2 CT x prevented the restacking, improved the conductivity and ameliorated the utilization efficiency of MoS 2 nanosheets, thereby achieving a fast electrochemical kinetic and high cycling stability.…”

Design of Vertically Aligned Two-Dimensional Heterostructures of Rigid Ti3C2TX MXene and Pliable Vanadium Pentoxide for Efficient Lithium Ion Storage

“…Therefore, distinct from the previous reported powder-like MXene/ V 2 O 5 composites, our design provides several merits that enhance the cycling stability and electrochemical kinetics of the as-prepared MXene/V 2 O 5 for charge storage applications. 23,24 Thick V-MXene/V 2 O 5 electrodes with loading levels of 5 and 6 mg cm −2 were electrochemically characterized as anodes for LIBs with improved output capacities, good cycling robustness, and rapid charge/discharge capability. The strategy for material design proposed in this study is feasible to be applied to other systems that involve directed mass transfer, for example filtration and catalysis.…”

Adjusting the 3d Orbital Occupation of Ti in Ti3C2 MXene via Nitrogen Doping to Boost Oxygen Electrode Reactions in Li–O2 Battery

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surface terminal and has been broadly studied as the electrocatalyst in electrochemical energy storage and conversion systems. [11][12][13][14] In general, the formula of MXene is M n+1 X n T x , where M represents the transition metal, X represents carbon or nitrogen, T x represents surface terminal (e.g., O, OH, F, etc. ), and n represents an integer from 1 to 3.

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