Phase change materials (PCMs) are ideal for thermal management in miniaturized and integrated electronic devices. However, developing PCMs with efficient thermal management and electromagnetic interference (EMI) shielding has remained a challenge to keep up with the rapid evolution of precision electronics. Herein, melamine foam (MF) was used as a template to build a continuous thermal/conductive network by dip-coating magnetized nickel (Ni)/MXene (NiM), and then, polyethylene glycol (PEG) was encapsulated into porous NiM/MF hybrid sponge via vacuum impregnation method. With the synergistic effect of magnetic Ni chain and highly conductive MXene, the obtained NiM/PCM achieve suitable thermal conductivity (0.39 W/mk), high electrical conductivity (76.3 S/m), and excellent EMI shielding effectiveness (34.6 dB). In addition, the NiM/PCM endows outstanding thermal stability, durability, and high latent heat storage capabilities. This work provides new ideas and insights for the EMI shielding and temperature protection of future microelectronic devices. Graphical abstract
Mixed ion–electron conductive (MIEC) bioelectronics has emerged as a state-of-the-art type of bioelectronics for bioelectrical signal monitoring. However, existing MIEC bioelectronics is limited by delamination and transmission defects in bioelectrical signals. Herein, a topological MXene network enhanced MIEC hydrogel bioelectronics that simultaneously exhibits both electrical and mechanical property enhancement while maintaining adhesion and biocompatibility, providing an ideal MIEC bioelectronics for electrophysiological signal monitoring, is introduced. Compared with nontopology hydrogel bioelectronics, the MXene topology increases the dynamic stability of bioelectronics by a factor of 8.4 and the electrical signal by a factor of 10.1 and reduces the energy dissipation by a factor of 20.2. Besides, the topology-enhanced hydrogel bioelectronics exhibits low impedance (<25 Ω) at physiologically relevant frequencies and negligible impedance fluctuation after 5000 stretch cycles. The creation of multichannel bioelectronics with high-fidelity muscle action mapping and gait recognition was made possible by achieving such performance.
Jinglian Zhu,Rui Shi,Yana Liu,Yunfeng Zhu,Jiguang Zhang,Xiaohui Hu,Liquan Li
3D interwoven Ti 3 C 2 MXene networks fabricated with the assistance of bacterial celluloses (BC) are used as a cathode material for rechargeable magnesium ion battery, which delivers an impressive specific capacity (171 mA h g −1 at 50 mA g −1 ) and good cycling performance (88% capacity retention after 100 cycles). In contrast, pure Ti 3 C 2 film only shows a reversible capacity of less than 10 mA h g −1 at 50 mA g −1 . Compared to pure Ti 3 C 2 film (d = 1.4 nm), 3D interwoven Ti 3 C 2 MXene networks (BC/Ti 3 C 2 film) possess larger interlayer spacing (d = 1.8 nm), benefiting the magnesium migration, which is proved through DFT calculation. BC/Ti 3 C 2 film with porous surface is observed through FESEM image. While for Ti 3 C 2 film, all flakes stack together. As expected, the diffusion paths for magnesium ions are optimized in the BC/Ti 3 C 2 film. Besides, Galvanostatic Intermittent Titration Technique shows a much larger magnesium diffusion coefficient of BC/Ti 3 C 2 film than that of pure Ti 3 C 2 film. Therefore, the larger interlayer spacing, optimized diffusion paths and larger magnesium diffusion coefficient contribute to the high electrochemical performance. Moreover, the working mechanisms of magnesium ion battery equipped with BC/Ti 3 C 2 film are investigated. This work provides a new insight to design MXene-based cathode materials with high-performance.
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