Boosted π-Li Cation Effect in the Stabilized Small Organic Molecule Electrode via Hydrogen Bonding with MXene

Abstract

The high solubility of the small organic molecule materials in organic electrolytes hinders their development in rechargeable batteries. Hence, this work designs an ultrarobust hydrogen-bonded organic–inorganic hybrid material: the small organic unit of the 1,3,6,8-tetrakis (p-benzoic acid) pyrene (TBAP) molecule connected with the hydroxylated Ti3C2T x MXene through hydrogen bonds between the terminal groups of −COOH and −OH. The robust and elastic hydrogen bonds can empower the TBAP, despite being a low-molecule organic chemical, with unusually low solubility in organic electrolytes and thermal stability. The alkali-treated Ti3C2T x MXene provides a hydroxyl-rich conductive network, and the small organic molecule of TBAP reduces the restacking of MXene layers. Therefore, the combination of these two materials complements each other well, and this organic–inorganic TBAP@D-Ti3C2T x electrode delivers large reversible capacities and long cyclic life. Notably, with the assistance of the in situ FT–IR characterization of the electrode within the fully lithiated (0.005 V) and the delithiated (3.0 V) states, it is revealed that a powerful π-Li cation effect mainly governs the lithium-storage mechanism with the highly activated benzene ring and each C6 aromatic ring, which can reversibly accept six Li-ions to form a 1:1 Li/C complex.

Multifunction E-Skin Based on MXene–PA–Hydrogel for Human Behavior Monitoring

“…Compared with the P–O bond vibration at 962 cm –1 in the M0 hydrogel, the P–O bond vibration shifts to 985 cm –1 in the M0.3 hydrogel, and there are two new peaks that appear at 786 and 668 cm –1 , which may arise from the formation of hydrogen bonds between hydroxyls in PVA chains and functional terminal groups (–F, –O, etc.) in MXene nanosheets . The typical elements of the M0 and M0.3 hydrogels can be seen in XPS (Figure c).…”

“…in MXene nanosheets. 41 The typical elements of the M0 and M0.3 hydrogels can be seen in XPS (Figure 2c). Apart from the characteristic element peaks at 135 eV (P), 284 eV (C), and 532 eV (O), the appearance of Ti and F elements at 450 and 686 eV further corroborates the successful synthesis of the PVA/PA/MXene composite hydrogel.…”

Facile fabrication of a novel self-healing and flame-retardant hydrogel/MXene coating for wood

“…The stress and strain of M0, M0.1, M0.2, M0.3 hydrogel could reach 0.076, 0.084, 0.105, 0.124 MPa and 150%, 220%, 280%, 310%, respectively. The enhancement in stress–strain curves of M-hydrogel can be ascribed to more hydrogen bonds and stronger polymer chain entanglement with the importation of MXene 42 . The functional groups in MXene can form hydrogen bonds with PVA and PA, resulting in more hydrogen bonds in M-hydrogel.…”

MXene‐Boosted Imine Cathodes with Extended Conjugated Structure for Aqueous Zinc‐Ion Batteries

“…As an attractive conductive agent, the MXene with single‐layered structure normally possesses better conductivity than that of the multi‐layered MXene. However, to enhance the kinetics of TAP electrode, the accordion‐like Ti 3 C 2 T x is chosen here owing to the following reasons: 1) The accordion‐like Ti 3 C 2 T x can act as a template to regulate the growth of TAP within the interlayers, improving the availability of active CN sites; [ 31 ] 2) Sufficient interlamellar spacing of accordion‐like Ti 3 C 2 T x can alleviate the volume expansion/contraction of TAP, suppressing the structural damage and dissolution during cycles; [ 32 ] 3) The interfacial availability of single‐layered Ti 3 C 2 T x subjects to the self‐restacking caused by the van der Waals’ force, [ 33 ] while the accordion‐like Ti 3 C 2 T x with incorporated TAP as organic fillers avoids lamellar stack, mobilizing the ion and electron transfer in the 3D TAP/Ti 3 C 2 T x heterostructure. [ 34 ] The uniform C, N, and Ti distribution in energy‐dispersive X‐ray spectroscopy images (Figure 3e) manifests the homogeneous TAP loading on the Ti 3 C 2 T x , which is also verified by the high‐resolution transmission electron microscopy (HRTEM) image (Figure 3f).…”