High‐Performance Biscrolled MXene/Carbon Nanotube Yarn Supercapacitors

Yarn‐shaped supercapacitors (YSCs) once integrated into fabrics provide promising energy storage solutions to the increasing demand of wearable and portable electronics. In such device format, however, it is a challenge to achieve outstanding electrochemical performance without compromising flexibility. Here, MXene‐based YSCs that exhibit both flexibility and superior energy storage performance by employing a biscrolling approach to create flexible yarns from highly delaminated and pseudocapacitive MXene sheets that are trapped within helical yarn corridors are reported. With specific capacitance and energy and power densities values exceeding those reported for any YSCs, this work illustrates that biscrolled MXene yarns can potentially provide the conformal energy solution for powering electronics beyond just the form factor of flexible YSCs.     

MXene Enhanced 3D Needled Waste Denim Felt for High-Performance Flexible Supercapacitors

MXene, a transition metal carbide/nitride, has been prominent as an ideal electrochemical active material for supercapacitors. However, the low MXene load limits its practical applications. As environmental concerns and sustainable development become more widely recognized, it is necessary to explore a greener and cleaner technology to recycle textile by-products such as cotton. The present study proposes an effective 3D fabrication method that uses MXene to fabricate waste denim felt into ultra...     

3D Printing of Freestanding MXene Architectures for Current‐Collector‐Free Supercapacitors

Additive manufacturing (AM) technologies appear as a paradigm for scalable manufacture of electrochemical energy storage (EES) devices, where complex 3D architectures are typically required but are hard to achieve using conventional techniques. The combination of these technologies and innovative material formulations that maximize surface area accessibility and ion transport within electrodes while minimizing space are of growing interest. Herein, aqueous inks composed of atomically thin (1–3 nm) 2D Ti₃C₂T_x with large lateral size of about 8 µm possessing ideal viscoelastic properties are formulated for extrusion‐based 3D printing of freestanding, high specific surface area architectures to determine the viability of manufacturing energy storage devices. The 3D‐printed device achieves a high areal capacitance of 2.1 F cm^?2 at 1.7 mA cm^?2 and a gravimetric capacitance of 242.5 F g^?1 at 0.2 A g^?1 with a retention of above 90% capacitance for 10 000 cycles. It also exhibits a high energy density of 0.0244 mWh cm^?2 and a power density of 0.64 mW cm^?2 at 4.3 mA cm^?2. It is anticipated that the sustainable printing and design approach developed in this work can be applied to fabricate high‐performance bespoke multiscale and multidimensional architectures of functional and structural materials for integrated devices in various applications.     

Interlayer Hydrogen‐Bonded Metal Porphyrin Frameworks/MXene Hybrid Film with High Capacitance for Flexible All‐Solid‐State Supercapacitors

2D metal‐porphyrin frameworks (MPFs) are attractive for advanced energy storage devices. However, the inferior conductivity and low structural stability of MPFs seriously limit their application as flexible free‐standing electrodes with high performance. Here, for the first time, an interlayer hydrogen‐bonded MXene/MPFs film is proposed to overcome these disadvantages by intercalation of highly conductive MXene nanosheets into MPFs nanosheets via a vacuum‐assisted filtration technology. The alternant insertion of MXene and MPFs affords 3D interconnected “MPFs‐to‐MXene‐to‐MPFs” conductive networks to accelerate the ionic/electronic transport rates. Meanwhile, the interlayer hydrogen bonds (F···H? O and O···H? O) contribute a high chemical stability due to a favorable tolerance to volume change caused by phase separation and structural collapse during the charge/discharge process. The synergistic effect makes MXene/MPFs film deliver a capacitance of 326.1 F g^?1 at 0.1 A g^?1, 1.64 F cm^?2 at 1 mA cm^?2, 694.2 F cm^?3 at 1 mA cm^?3 and a durability of about 30 000 cycles. The flexible symmetric supercapacitor shows an areal capacitance of 408 mF cm^?2, areal energy density of 20.4 µW h cm^?2, and capacitance retention of 95.9% after 7000 cycles. This work paves an avenue for the further exploration of 2D MOFs in flexible energy storage devices.     

Highly Conductive Ti3C2Tx MXene Hybrid Fibers for Flexible and Elastic Fiber‐Shaped Supercapacitors

Fiber‐shaped supercapacitors (FSCs) are promising energy storage solutions for powering miniaturized or wearable electronics. However, the scalable fabrication of fiber electrodes with high electrical conductivity and excellent energy storage performance for use in FSCs remains a challenge. Here, an easily scalable one‐step wet‐spinning approach is reported to fabricate highly conductive fibers using hybrid formulations of Ti₃C₂T_x MXene nanosheets and poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate. This approach produces fibers with a record conductivity of ≈1489 S cm^?1, which is about five times higher than other reported Ti₃C₂T_x MXene‐based fibers (up to ≈290 S cm^?1). The hybrid fiber at ≈70 wt% MXene shows a high volumetric capacitance (≈614.5 F cm^?3 at 5 mV s^?1) and an excellent rate performance (≈375.2 F cm^?3 at 1000 mV s^?1). When assembled into a free‐standing FSC, the energy and power densities of the device reach ≈7.13 Wh cm^?3 and ≈8249 mW cm^?3, respectively. The excellent strength and flexibility of the hybrid fibers allow them to be wrapped on a silicone elastomer fiber to achieve an elastic FSC with 96% capacitance retention when cyclically stretched to 100% strain. This work demonstrates the potential of MXene‐based fiber electrodes and their scalable production for fiber‐based energy storage applications.     

MoS2/MXene纳米复合物的研究进展

与单一的二维材料MoS2和MXene相比,MoS2/MXene纳米复合物具有优异且稳定的物理化学性能,受到了国内外研究者的广泛关注.本论文对MoS2/MXene纳米复合物的最新研究现状进行了综述.首先,阐述MoS2/MXene纳米复合物的制备方法及其优缺点,包括水热法、插层法和热退火法等.其次,介绍MoS2/MXene...     

石墨烯/聚苯胺基超级电容器研究进展

近年来,超级电容器以其优异的性能引起了研究者的广泛兴趣。其中以石墨烯为基质的电极材料占研究的绝大部分,同时质子化的聚苯胺也是一种高比电容的电极材料,将石墨烯与聚苯胺复合,利用二者的协同作用可以有效提高电容器的性能。主要介绍了二者的复合方式及复合材料的电容性能,总结了石墨烯/聚苯胺电极材料电容器的研究进展,最后对该领域的发展进行了展望。     

MXene/铜合金复合材料的制备与性能研究

采用分子级混合方法及SPS烧结技术制备了Ti₃C₂T_x含量分别为5vol%、10vol%和20vol%的Cu/Ti₃C₂T_x复合材料, 研究了Ti₃C₂T_x含量对铜基复合材料的导电性、力学性能及摩擦磨损性能的影响。研究发现: 随Ti₃C₂T_x含量增加, Cu/Ti₃C₂T_x复合材料的相对密度及电导率均持续下降, 拉伸强度则先升高后下降; 当Ti₃C₂T_x含量为5vol%时, Cu/Ti₃C₂T_x复合材料的拉伸强度相比纯铜提高了43%。添加Ti₃C₂T_x可以明显改善Cu/Ti₃C₂T_x复合材料的摩擦磨损性能, 当Ti₃C₂T_x含量为10vol%时, Cu/Ti₃C₂T_x复合材料的磨损率仅为2.55×10^-7 mm³/(N·m), 比纯铜降低了一个数量级。     

Ultrastretchable MXene Microsupercapacitors

Stretchable microsupercapacitors represent emerging miniaturized energy-storage devices for next-generation deformable electronics. Two-dimensional (2D) transition metal carbides (MXenes) are considered attractive electrode materials due to their metallic conductivity, hydrophilic surfaces, and excellent processability. Here, an ultrastretchable microsupercapacitor of interdigitated MXene microelectrodes with crumpled surface textures is created. The microsupercapacitor shows a series of attractive properties including a high specific capacitance of ≈185 mF cm⁻², ultrahigh stretchability up to 800% area strain, and ≈89.7% retention of the initial capacitance after 1000 stretch–relaxation cycles. In addition to static strains, the microsupercapacitor demonstrates robust mechanical properties to retain stable charging–discharging capability under dynamic stretching at different strain rates. A self-powering circuit system utilizes four microsupercapacitor packs to power a light-emitting diode (LED) array, which exhibits stable operations under large tensile strain and skin-attached wearable settings. The developments offer a generic design strategy to enhance the deformability of microsupercapacitors based on 2D nanomaterials.     

MXene/硅橡胶复合材料的制备及导热性能

随着5G时代的来临,各类电子元器件发热功率明显增大。因此,电子元器件及设备的散热问题亟待解决,使得对高导热材料的需求日益迫切。为此,利用化学刻蚀法制备二维MXene材料(Ti3C2Tx),采用标准溶液共混法,将制备得到的MXene与硅橡胶复合,得到MXene/硅橡胶复合材料,研究了MXene添加量对MXene/硅橡胶导热性能的影响。使用SEM和XRD对MXene进行结构表征,并测试纯硅橡胶与MXene/硅橡胶复合材料的力学性能、导热导电性能和热稳定性等。结果表明：化学刻蚀法成功制备了呈经典“手风琴”层状结构的MXene,当MXene添加量为2.00wt%时,MXene/硅橡胶复合材料的热导率最高可达1.32 W/(m·K),是纯硅橡胶的4.55倍,此时,体积电阻率降低4个数量级,力学性能和热稳定性也得到了显著提高。     

Highly conductive dodecaborate/MXene composites for high performance supercapacitors

With the increasingly prominent energy and environmental issues, the supercapacitors, as a highly efficient and clean energy conversion and storage devices, meet the requirements well. However, it is still a challenge to enhance the capacitance and energy density of supercapacitors. A novel and highly conductive dodecaborate/MXene composites have been designed for high performance supercapacitors. The surface charge property of MXene was modified by a simple ultrasonic treatment with ammonium ion, and the dodecaborate ion can be inserted into the inner surface of MXene by electrostatic adsorption. Due to the unique icosahedral cage conjugate structure formed by the B-B bond and the highly delocalized three-dimensional π bond structure of the electrons, the negative charge is delocalied on the whole dodecaborate ion, which reduces the ability to bind to cations. Therefore, the cations can move easily, and the dodecaborate can act as a “lubricant” for ion diffusion between the MXene layers, which significantly improves the ion transfer rate of supercapacitors. The dodecaborate/MXene composites can achieve an extremely high specific capacitance of 366 F.g^-1 at a scan rate of 2 mV.s^-1, which is more than eight times higher than that of MXene (43 F^1-) at the same scan rate. Our finding provides a novel route on the fabrication of the high performance supercapacitors.

     

仿生构筑超薄MXene/CNC电磁屏蔽复合薄膜

高强电磁屏蔽薄膜材料在柔性器件、汽车电子和航空航天等领域具有广泛应用前景, 受珍珠母微纳米结构及其优异机械性能的启发, 利用简单的溶液共混及真空抽滤方法, 将纤维素纳米晶(CNC)和MXene混合, 经层层组装制备了高性能MXene基复合薄膜。结果表明: 薄膜的机械性能有了显著提高, 拉伸强度从18 MPa提高到57 MPa, 韧性从70 kJ/m ³提高到313 kJ/m ³, 同时保留了复合薄膜的高电导率(10 ⁴ S/m)和优异的电磁屏蔽性能, 厚度8 μm时可达40 dB以上。     

Development of NiOOH Nanosheet/Graphene Hydrogels for Asymmetric Supercapacitors

正NiOOH nanosheet/graphene hydrogels(HNiOOH/GS),with mesoporous NiOOHnanosheets uniformly dispersed within the highly in-terconnected 3D graphene network,are construct-ed and studied for the first time by a mixed solvo-thermal and hydrothermal reaction.The effect of sol-vent composition on the morphology,phase,anddispersibility of nanocrystal and hydrogel strength is     

Flexible/Stretchable Supercapacitors with Novel Functionality for Wearable Electronics

With the miniaturization of personal wearable electronics, considerable effort has been expended to develop high-performance flexible/stretchable energy storage devices for powering integrated active devices. Supercapacitors can fulfill this role owing to their simple structures, high power density, and cyclic stability. Moreover, a high electrochemical performance can be achieved with flexible/stretchable supercapacitors, whose applications can be expanded through the introduction of additional novel functionalities. Here, recent advances in and future prospects for flexible/stretchable supercapacitors with innate functionalities are covered, including biodegradability, self-healing, shape memory, energy harvesting, and electrochromic and temperature tolerance, which can contribute to reducing e-waste, ensuring device integrity and performance, enabling device self-charging following exposure to surrounding stimuli, displaying the charge status, and maintaining the performance under a wide range of temperatures. Finally, the challenges and perspectives of high-performance all-in-one wearable systems with integrated functional supercapacitors for future practical application are discussed.