A Thermally Chargeable Supercapacitor based on the g‐C₃N₄‐Doped PAMPS/PAA Hydrogel Solid Electrolyte and 2D MOF@Ti₃C₂T_x MXene Heterostructure Composite Electrode

Abstract

With the development of individual wearable electronics, the requirements of self‐energy harvest devices from human skin or motion have increased. A thermal harvest device that receives thermal energy naturally existed in human skin is more attractive than a mechanical energy harvester that needs human motion or walking. Herein, a thermal‐chargeable supercapacitor (TCSC) is proposed, which can convert thermal energy into electrical energy and then store the energy only by occurring the temperature difference between the two ends of the TCSC. The all‐solid‐state g‐C3N4‐modified hydrogel electrolyte in the TCSC provides more free protons and energy for proton migration by the electrostatic interaction and hydrogen bond interaction between g‐C3N4 and the acid group. The 2D MOF@Ti3C2Tx MXene heterojunction electrodes with the advantages of large pore size, adjustable and abundant REDOX sites of MOFs, and high conductivity of Ti3C2Tx MXene also ensure the high performance of the TCSC. As a result, the assembled TCSC exhibits excellent ionic thermal‐voltage (55.68 mV), Seebeck coefficient (18.56 mV K−1), and energy exchange efficiency (3.4%) upon a temperature difference of 3 K, and successfully drives the pressure sensor work.

Eye-wearable Ti3C2Tx MXene-based micro-supercapacitor as a power unit for intraocular pressure applications

“…More importantly, the electrode was peeled off with a water-soluble film and adapted to attach to the hemispherical substrate by the force of water, thereby avoiding the damage to the electrodes prevalent in conventional thermal pressing techniques. 27 Finally, an eye-compatible NaCl/PVA-gel electrolyte and PDMS encapsulation were applied dropwise to the electrodes to prevent eye damage from the leakage of conventional electrolytes.…”

MXene-Based Skin-Like Hydrogel Sensor and Machine Learning-Assisted Handwriting Recognition

“…As a two-dimensional inorganic material composed of transition metal carbides and nitrides, MXene has a unique structure and compelling properties such as excellent conductivity, high surface area, tunable surface functional groups, and outstanding hydrophilicity. , Furthermore, MXene has chemical stability, − which makes it an ideal conductive material, and is widely used by researchers in flexible sensors, , supercapacitors, catalysts, , and electromagnetic interference. , However, MXene hydrogel exhibits a low elongation at break, which leads to easy damage during stretching. Additionally, its elastic modulus is not compatible with human tissues, limiting its practical applications in flexible sensors.…”

MXene based flexible photodetectors: progress, challenges, and opportunities

“…2D transition-metal carbides and nitrides (MXenes) produced by selective exfoliation of MAX phases (A is a main group sp element from groups 13 and 14) correspond to the general formula M n +1 X n T x , where M is an early transition metal, X represents carbon and/or nitrogen, T x stands for hydroxyl (–OH), oxygen (–O), or fluorine (–F) termination, n = 1–4. 1–4 In addition to their sharp excellence in the field of energy storage, 5–9 sensors, 10–16 triboelectric devices, 17 electromagnetic interference shielding, 18–20 transparent electrodes, 21,22 catalysis, 23 thermoelectric, 24 water purification, 25 and desalination since their first synthesis in 2011, 26–28 the application of MXenes in various flexible optoelectronic devices that cannot be ignored has aroused increasing attention triggered by their outstanding mechanical, physical and chemical properties. 29–33…”