Multifunctional MXene/Carbon Nanotube Janus Film for Electromagnetic Shielding and Infrared Shielding/Detection in Harsh Environments.

Multifunctional, flexible, and robust thin films capable of operating in demanding harsh temperature environments are crucial for various cutting-edge applications. This study presents a multifunctional Janus film integrating highly-crystalline Ti3C2Tx MXene and mechanically-robust carbon nanotube (CNT) film through strong hydrogen bonding. The hybrid film not only exhibits high electrical conductivity (4250 S cm-1), but also demonstrates robust mechanical strength and durability in both extremely low and high temperature environments, showing exceptional resistance to thermal shock. This hybrid Janus film of 15 µm thickness reveals remarkable multifunctionality, including efficient electromagnetic shielding effectiveness of 72 dB in X band frequency range, excellent infrared (IR) shielding capability with an average emissivity of 0.09 (a minimal value of 0.02), superior thermal camouflage performance over a wide temperature range (- 1 to 300 °C) achieving a notable reduction in the radiated temperature by 243 °C against a background temperature of 300 °C, and outstanding IR detection capability characterized by a 44% increase in resistance when exposed to 250 W IR radiation. This multifunctional MXene/CNT Janus film offers a feasible solution for electromagnetic shielding and IR shielding/detection under challenging conditions.

Effects of the aspect ratio of the conductive agent on the kinetic properties of lithium ion batteries.

We fabricated lithium-ion batteries (LIBs) using the Super P and carbon nanotubes (CNTs) as conductive agents to investigate the effect of the aspect ratio of conductive agent on the kinetic properties of LIB. The electrode fabricated with CNTs, which have a high aspect ratio (length: 200 µm), exhibited outstanding rate capability at 30C despite of their low concentration, while the electrode fabricated with the carbon black showed poor rate capability. These results indicate that the aspect ratio of conductive agent influence the diffusion coefficient of lithium ions, which is calculated from the galvanostatic intermittent titration technique analysis, and that conductive agent should have high aspect ratio to improve the kinetic properties of LIBs. This study provides insights that are useful for designing high-performance LIBs by reducing the amount of conductive agent, leading to increased loading of active material.