One‐Dimensional π‐d Conjugated Coordination Polymer Intercalated MXene Compound for High‐Performance Supercapacitor Electrode

Abstract

MXenes possess the characteristics required for high-performance supercapacitors, such as high metallic conductivity and electrochemical activity, but their full potential remains unrealized owing to their tendency to self-restack when fabricated into an electrode. Designing an MXene interlayer with an effective intercalant has, therefore, become an important criterion to alleviate the restacking issue while also synergistically interact with MXene to further improve its electrochemical activity. This study reports the intercalation of 1D 𝝅-d conjugated coordination polymer (Ni-BTA) within the Ti 3 C 2 T x nanosheet for the fabrication of a highly efficient supercapacitor electrode. Ni-BTA, which consists of a nickel center and 1,2,4,5-benzenetetramine (BTA) organic chain, is uniformly intercalated by direct synthesis on the abundant oxygen terminals on the Ti 3 C 2 T x nanosheet surface. The intercalated Ni-BTA acts as an effective charge carrier transportation pathway through its 1D stretched delocalized 𝝅-d electrons while participating in pseudocapacitive activity with the Ni centers. As a result, the Ni-BTA/MXene film exhibits excellent rate performance and a gravimetric specific capacitance of 264.4 F g −1 at 5 mV s −1 . This magnitude is retained up to 94.6% after 10 000 cycles. The present study provides insights into the design of MXene interlayers for the fabrication of highly robust and stable supercapacitors.

Flexible and Simply Degradable MXene–Methylcellulose Piezoresistive Sensor for Human Motion Detection

“…MXenes are a class of two-dimensional transition metal carbides or nitrides, typically synthesized by etching a monatomic metal layer in the MAX precursor, where M denotes a transition metal (e.g., titanium, chromium, and vanadium), A is typically an element from group 13 or 14, and X is carbon and/or nitrogen. − In recent years, MXenes have shown great potential for applications in the fields of catalysis, energy storage, sensing, and electromagnetic shielding. − Currently, the most common method is to dope or compound various organic compounds in MXenes to improve their material properties. For example, in energy storage, Xu et al utilized the chemical oxidative polymerization of aniline monomers on the MXene layer to provide a large number of channels for the entry of electrolyte ions, thus improving the ion transport efficiency and electrochemical activity .…”

A two-dimensional semiconducting Cu(i)-MOF for binder and conductive additive-free supercapattery

“…Pseudocapacitors store charge as a result of surface redox reactions, whereas EDLCs store charge due to the accumulation of ions at the electrode/electrolyte interface, where no electron transfer is involved. 9,10 Supercapacitors also offer the advantages of fast discharging, long cyclic stability, being lightweight, and simple to use. 11,12 Recently, efforts have been made to combine the properties of both supercapacitors and batteries in a single electrode material to develop a new category called “supercapattery” that combines the benefits of high energy as well as high power density.…”

Progress of 2D MXene as an Electrode Architecture for Advanced Supercapacitors: A Comprehensive Review

“…The MXene–metal oxide composites have high electrical conductivity, greater volumetric capacitance, and electrochemical stability, making them apt electrode materials for flexible supercapacitors. , The electrochemical efficiency of MXenes varies with the thickness of the electrode. One approach to overcoming this challenge is by creating composites of MXene with the polymer. , Yuan et al synthesized the MXene/CNF/PANI composite as a suitable electrode for high-performance supercapacitors . A novel water-free etching method has free layered Ti 3 C 2 T x MXenes in deep eutectic solvents at room temperature and exhibits splendid specific capacitance of 320 F/g at 2 mV/s .…”

“…One approach to overcoming this challenge is by creating composites of MXene with the polymer. 35 , 36 Yuan et al synthesized the MXene/CNF/PANI composite as a suitable electrode for high-performance supercapacitors. 37 A novel water-free etching method has free layered Ti 3 C 2 T x MXenes in deep eutectic solvents at room temperature and exhibits splendid specific capacitance of 320 F/g at 2 mV/s.…”