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For the first time, few-layer Ti3C2Tx (FL-Ti3C2Tx) supporting highly dispersed nano-Ni particles with an interconnected and interlaced structure was elaborated through a self-assembly reduction pro...

Favourable effects of oxygen vacancies in TiO2-x synthesized via a calcination method on the electrochemical performance of dual Mg/Li-ion batteries are investigated. The dual-ion cell shows excellent rate capabilities up to 40 C and outstanding cyclability up to 2500 cycles.

For the first time, few-layer Ti

Favourable effects of oxygen vacancies in TiO2-x synthesized via a calcination method on the electrochemical performance of dual Mg/Li-ion batteries are investigated. The dual-ion cell shows excellent rate capabilities up to 40 C and outstanding cyclability up to 2500 cycles.

Rechargeable magnesium batteries (rMBs) are promising techniques suitable for large-scale energy storage systems with low-cost and high safety. However, their development is severely hindered by strong coulombic effect between bivalent Mg2+ and cathode materials. In this work, two dimensional hierarchical nano-micro hybrids are synthesized by in-situ generating VS4 nanosheets on carbon-coated Ti3C2 MXene matrix (denoted as VS4@Ti3C2/C). A high-performance rMB system is built by using the hierarchical nano-micro hybrids cathode, magnesium foil anode, and 0.25 M methylpyrrolidinium chloride in 0.25 M 2PhMgCl-AlCl3/tetrahydrofuran as the electrolyte. The existence of V–C bond proves that VS4 is anchored on the surface of Ti3C2 via a strong chemical bond, rather than simply by adsorption. The unique hierarchical nano-micro structure improves the accessibility of the electrolyte and reduces the charge transfer resistance, leading to a high discharge capacity of 492 mA h g−1 at 50 mA g−1, an outstanding rate performance of 129 mA h g−1 at 1000 mA g−1, and excellent cycling performance (over 900 cycles at 500 mA g−1). Moreover, reversible intercalation of MgCl + into VS4@Ti3C2/C is revealed by investigating the evolution of the hybrids during different electrochemical states. This study will shed light on designing high-performance MXene-based cathode materials for multivalent batteries.

Sandwich like Ni/Ti3C2 catalysts with interfacial differences were controllably fabricated via modified wet chemical method. Through changing the solvents (water, ethylene glycol and an equal mixture of the two), Ni nanoparticles with different morphologies (size and dispersibility) on Ti3C2 matrix can be attained, leading to different interfaces between Ni nanoparticles and Ti3C2 matrix. After ball milling with MgH2, the Ni/Ti3C2 catalyst prepared from the mixed solvent (Ni/Ti3C2-WE) shows the best catalytic activity, which exhibits the minimum Ni particle size and crystallite size, and the best dispersion of Ni nanoparticles on Ti3C2 matrix. The electronic interaction brought by the rich interfaces and contacts between Ni nanoparticles and Ti3C2 matrix can dramatically improve the hydrogen storage performance of MgH2. In addition, electron transfers in multiple valence Ti (Ti0, Ti2+, Ti3+, Ti4+) and the unique structure of sandwich like Ni/Ti3C2 catalyst are also deemed as very crucial factors for enhancing catalytic activity of Ni/Ti3C2-WE. This research has shown the importance of the interfacial interaction between multiphase of catalysts on improving hydrogen storage performance of Mg-based materials experimentally and theoretically, providing a guideline to elaborate high efficiency multiphase catalysts.

NiSe2/Ti3C2 hybrid prepared by the one-step hydrothermal method is used as a cathode material for Mg/Li hybrid ion battery (MLIB) for the first time. The NiSe2/Ti3C2 hybrid shows exciting electrochemical performance, with a reversible capacity of 150 mA h g−1 at a very high current density of 5 A g−1. In contrast, pure NiSe2 only has a capacity of 50 mA h g−1 at 5 A g−1. The sharp improvement can be ascribed to the enhanced conductivity and the lowered charge-transfer resistance (Rct) when Ti3C2 is introduced. Moreover, the working mechanism of NiSe2/Ti3C2 in MLIB is investigated. This work provides a novel method to design cathode materials with high rate performance by combining MXenes with metal selenides.

3D interwoven Ti3C2 MXene networks fabricated with the assistance of bacterial celluloses (BC) are used as a cathode material for rechargeable magnesium ion battery, which delivers an impressive specific capacity (171 mA h g−1 at 50 mA g−1) and good cycling performance (88% capacity retention after 100 cycles). In contrast, pure Ti3C2 film only shows a reversible capacity of less than 10 mA h g−1 at 50 mA g−1. Compared to pure Ti3C2 film (d = 1.4 nm), 3D interwoven Ti3C2 MXene networks (BC/Ti3C2 film) possess larger interlayer spacing (d = 1.8 nm), benefiting the magnesium migration, which is proved through DFT calculation. BC/Ti3C2 film with porous surface is observed through FESEM image. While for Ti3C2 film, all flakes stack together. As expected, the diffusion paths for magnesium ions are optimized in the BC/Ti3C2 film. Besides, Galvanostatic Intermittent Titration Technique shows a much larger magnesium diffusion coefficient of BC/Ti3C2 film than that of pure Ti3C2 film. Therefore, the larger interlayer spacing, optimized diffusion paths and larger magnesium diffusion coefficient contribute to the high electrochemical performance. Moreover, the working mechanisms of magnesium ion battery equipped with BC/Ti3C2 film are investigated. This work provides a new insight to design MXene-based cathode materials with high-performance.