Recyclable Conjugated Polyelectrolyte Hydrogels for Pseudocapacitor Fabrication

In alignment with widespread interest in carbon neutralization and sustainable practices, we disclose that conjugated polyelectrolyte (CPE) hydrogels are a type of recyclable, electrochemically stable, and environmentally friendly pseudocapacitive material for energy storage applications. By leveraging ionic-electronic coupling in a...

Holistic Processing of Sawdust to Enable Sustainable Hybrid Li-Ion Capacitors

Activated carbon has long been recognized as a promising electrode material for energy storage devices. The extraordinarily high specific area makes it challenging to replace in supercapacitors since electrical double-layer capacitors need such surfaces but also porous networks to enable electrolyte penetration. As a raw material for...

Enhancing pseudocapacitive intercalation in Ti₃C₂T _x MXene with molecular crowding electrolytes

The growing demand for safe, cost-efficient, high-energy and high-power electrochemical energy storage devices has stimulated the development of aqueous-based supercapacitors with high capacitance, high rate capability, and high voltage. 2D titanium carbide MXene-based electrodes have shown excellent rate capability in various dilute aqueous...

In situ monitoring redox processes in energy storage using UV–Vis spectroscopy

Understanding energy storage mechanisms in electrochemical energy storage devices lays the foundations for improving their energy and power density. Here we introduce in situ ultraviolet–visible (UV–Vis) spectroscopy method to distinguish battery-type, pseudocapacitive and electrical double-layer charge storage processes. On the basis of Ti...

Elucidation of the Charging Mechanisms and the Coupled Structural–Mechanical Behavior of Ti₃C₂T_x (MXenes) Electrodes by In Situ Techniques

The discovery of the Ti₃C₂T_x compounds (MXenes) a decade ago opened new research directions and valuable opportunities for high-rate energy storage applications. The unique ability of the MXenes to host various mono- and multivalent cations and their high stability in different electrolyte environments...

MXene Chemistry and Applications

Pseudocapacitive gels based on conjugated polyelectrolytes: thickness and ion diffusion limitations

Conjugated polymer hydrogels (CPHs) are emerging pseudocapacitive materials capable of forming redox-active hydrogels. Current efforts focus on increasing their areal capacitance (C_Areal) and cycling stabilities by using binders tolerant to H₂SO₄-based electrolytes, while alternatives in more environmentally...

Interfacial Designs of MXenes for Mild Aqueous Zinc-Ion Storage

Limited Li resources, high cost, and safety risks of using organic electrolytes have stimulated a strong motivation to develop non-Li aqueous batteries. Aqueous Zn-ion storage (ZIS) devices offer low-cost and high-safety solutions. However, their practical applications are at the moment restricted by their short cycle life arising mainly from...

Structure Design and Processing Strategies of MXene-Based Materials for Electromagnetic Interference Shielding

The development of new materials for electromagnetic interference (EMI) shielding is an important area of research, as it allows for the creation of more effective and high-efficient shielding solutions. In this sense, MXenes, a class of 2D transition metal carbides and nitrides have exhibited promising performances as EMI shielding materials...

Conjugated Polyelectrolyte Thin Films for Pseudocapacitive Applications

A subclass of organic semiconductors known as conjugated polyelectrolytes (CPEs) is characterized by a conjugated backbone with ionic pendant groups. The water solubility of CPEs typically hinders applications of thin films in aqueous media. Herein, it is reported that films of an anionic CPE, namely CPE-K, drop cast from water produces...

Increasing the molecular weight of conjugated polyelectrolytes improves the electrochemical stability of their pseudocapacitor gels

Conjugated polyelectrolyte (CPE) hydrogels synergize the electrical properties of redox-active polymers with the physical properties of hydrogels. Of particular relevance is their implementation as pseudocapacitors due to their high ionic conductivity, strong ionic-electronic coupling, and large electroactive surface area. To date, efforts to...

Effect of pinholes in Nb₄C₃ MXene sheets on its electrochemical behavior in aqueous electrolytes

Two-dimensional (2D) niobium carbide, Nb₄C₃T_x (T_x: O, OH, and F), a representative member of the 43 MXene structural motif, has shown promising electrochemical performance in acidic electrolytes. The capacitive performance of Nb₄C₃T_x in neutral aqueous electrolytes...

Surface Redox Pseudocapacitance of Partially Oxidized Titanium Carbide MXene in Water-in-Salt Electrolyte

Achieving pseudocapacitive intercalation in MXenes with neutral aqueous electrolytes and driving reversible redox reactions is scientifically appealing and practically useful. Here, we report that the partial oxidation of MXene intensifies pseudocapacitive Li+ intercalation into Ti3C2Tx MXene from neutral water-in-salt electrolytes. An in...

Design and characterization of 2D MXene-based electrode with high-rate capability

MXenes, two-dimensional transition metal carbides and nitrides, are promising materials for electrochemical energy storage application due to their redox-active surface and flexible interlayer space. Among all reported MXene-based electrodes, some have shown significantly better high-rate energy storage capabilities. Hence, it is crucial to...