Interlayer and intralayer co-modified flexible V2CTX MXene@SWCNT films for high-power Li-ion capacitors

Bidirectional Construction of 3D Flexible Ti3C2Tx MXene Films for High-Performance Lithium-Ion Capacitors

“…Additionally, the weakening of the peak intensity of F 1s and the enhancement of the peak intensity of O 1s imply the success of the targeted substitution of the Ti 3 C 2 T x MXene terminal groups from −F to −O after alkali treatment and calcination at 400 °C. The surface-modified MXene delivers quite high Li + ions storage capabilities. − Figure e shows the XPS spectra of C 1s of Ti 3 C 2 T x and KTi 3 C 2 -O with binding energies at 281.83, 284.85, 286.53, and 289.09 eV, representing C–Ti, C–C, C–O, and O–CO bonds, respectively. Notably, originating from the intercalation of K + ions, the C 1s spectrum of KTi 3 C 2 -O shows two new characteristic peaks around 295.83 and 293.11 eV that can be assigned to K 2p1/2 and 2p3/2 orbitals, while Ti 3 C 2 T x has no corresponding peaks.…”

A comprehensive overview of MXene‐based anode materials for univalent metal ions (Li+, Na+, and K+) and bivalent zinc ion capacitor application

“…In another recent report, Wang et al [151] . synthesized a freestanding VCT‐K@C composite film electrode by the interlayer (K + intercalation)/intralayer (−O functional group attachment) co‐modification of V 2 CT x MXene (VCT‐K) followed by the combination with the conducting networks of single‐walled CNT (SWCNT) (Figure 10a).…”

“…In another recent report, Wanget al [151] synthesized a freestanding VCT-K@C composite film electrode by the interlayer (K + intercalation)/intralayer (À O functional group attachment) co-modification of V 2 CT x MXene (VCT-K) followed by the combination with the conducting networks of single-walled CNT (SWCNT) (Figure 10a). The intercalation of K + enlarges the interlayer spacing of MXene for more active sites, the À O enriched functionality of MXene (obtained by replacing À F terminals with À OH followed by annealing) improves the Li + storage ability, and SWCNT provides a conductive bridge for efficient ion exchange-migration.…”

“…However, synthesis of the fluorine‐free MXene is not as simple as typical HF‐based etching protocol. Therefore, synthetic up‐gradation of the fluorine free‐MXene is vital and may be explored in the advancement of MICs. Apart from Ti 3 C 2 T x ‐based anode, the performance of Nb 2 CT x /V 2 CT x ‐based anode materials is also promising, [141,151,168] which opens immense possibility to explore other experimentally synthesized MXenes (about 30 in numbers). Therefore, development of a simple, cost effective, and large scale synthetic protocol for various MXenes is an important aspect for practical implication. Like graphene, the layer restacking and irreversible aggregation of the MXene nanosheets/flakes are critical to limit the accessibility of ionic electrolytes.…”

A hollow nano-flower NiCo2O4@Nb2CTx MXene heterostructure via interfacial engineering for high-performance flexible supercapacitor electrodes

“…Classic devices are difficult to satisfy the demand for portable or wearable consumer electronics owing to their bulky weight and rigidity, which cannot be easily bent. Recently, tremendous pioneering works have been conducted to develop portable or wearable consumer devices, including batteries and supercapacitors (such as Li-ion capacitors, [1][2][3] potassium-ion capacitors [4][5][6] and Zn-ion capacitors [7][8][9] ). Combining electrode materials with a exible substrate (carbon ber 10 and nanober membrane 11,12 ) is one of the simplest and most effective strategies for preparing exible supercapacitor electrodes.…”