自修复聚合物在电化学储能领域的研究进展

自修复聚合物材料能够自行修复在加工和使用过程中产生的微观或者宏观损伤,从而解决材料内部微裂纹难以检测和修复的问题,保持其结构和功能的完整性。将自修复聚合物应用于电化学储能器件中,可有效提升器件的安全可靠性和使用寿命,成为近年来的研究热点之一。本文概括介绍了外援型和本征型自修复聚合物材料的修复机理,着重总结了不需要修复剂、且可实现多次可逆修复的本征型自修复聚合物应用于电化学储能领域的研究进展,以储能器件的电极、电解质以及界面为出发点,综述了自修复功能聚合物分别作为高比能电极黏结剂、界面修饰层、可自修复电解质的研究进展,阐述了自修复机理及其对储能器件电化学性能的影响规律,探讨了自修复聚合物材料在储能领域未来的发展方向。     

An Electrochemical Gelation Method for Patterning Conductive PEDOT:PSS Hydrogels

Due to their high water content and macroscopic connectivity, hydrogels made from the conducting polymer PEDOT:PSS are a promising platform from which to fabricate a wide range of porous conductive materials that are increasingly of interest in applications as varied as bioelectronics, regenerative medicine, and energy storage. Despite the promising properties of PEDOT:PSS‐based porous materials, the ability to pattern PEDOT:PSS hydrogels is still required to enable their integration with multifunctional and multichannel electronic devices. In this work, a novel electrochemical gelation (“electrogelation”) method is presented for rapidly patterning PEDOT:PSS hydrogels on any conductive template, including curved and 3D surfaces. High spatial resolution is achieved through use of a sacrificial metal layer to generate the hydrogel pattern, thereby enabling high‐performance conducting hydrogels and aerogels with desirable material properties to be introduced into increasingly complex device architectures.     

导电水凝胶在柔性可穿戴传感器的应用研究进展

目的 概述导电水凝胶在柔性可穿戴传感器方面的研究情况,挖掘其作为传感器件的应用潜能。方法 查阅大量相关的文献,对导电水凝胶在柔性可穿戴传感领域的最新进展进行归纳与总结。按水凝胶网络分类的4种导电水凝胶,总结归纳其设计、合成、结构和潜在应用。讨论导电水凝胶的导电性、力学性能、黏附性、防冻性能、自愈性能和各式响应性等功能性能的影响因素,总结自黏性、防冻性、自修复和其他多种优秀性能的柔性可穿戴传感器。结论 导电水凝胶是一种具有多功能的独特刺激响应性的功能材料,在柔性可穿戴传感领域进行深入探究具有重大意义。     

2D Metal Chalcogenides Incorporated into Carbon and their Assembly for Energy Storage Applications

2D metal chalcogenides have become a popular focus in the energy storage field because of their unique properties caused by their single‐atom thicknesses. However, their high surface energy and van der Waals attraction easily cause serious stacking and restacking, leading to the generation of more inaccessible active sites with rapid capacity fading. The hybridization of 2D metal chalcogenides with highly conductive materials, particularly, incorporating ultrasmall and few‐layered metal chalcogenides into carbon frameworks, can not only maximize the exposure of active sites but also effectively avoid their stacking and aggregation during the electrochemical reaction process. Therefore, a satisfactory specific capacity will be achieved with a long cycle life. In this Concept, the representative progress on such intriguing nanohybrids and their applications in energy storage devices are mainly summarized. Finally, an outlook of the future development and challenges of such nanohybrids for achieving an excellent energy storage capability is also provided.     

Smart Eutectic Gallium–Indium: From Properties to Applications

Eutectic gallium–indium (EGaIn), a liquid metal with a melting point close to or below room temperature, has attracted extensive attention in recent years due to its excellent properties such as fluidity, high conductivity, thermal conductivity, stretchability, self-healing capability, biocompatibility, and recyclability. These features of EGaIn can be adjusted by changing the experimental condition, and various composite materials with extended properties can be further obtained by mixing EGaIn with other materials. In this review, not only the are unique properties of EGaIn introduced, but also the working principles for the EGaIn-based devices are illustrated and the developments of EGaIn-related techniques are summarized. The applications of EGaIn in various fields, such as flexible electronics (sensors, antennas, electronic circuits), molecular electronics (molecular memory, opto-electronic switches, or reconfigurable junctions), energy catalysis (heat management, motors, generators, batteries), biomedical science (drug delivery, tumor therapy, bioimaging and neural interfaces) are reviewed. Finally, a critical discussion of the main challenges for the development of EGaIn-based techniques are discussed, and the potential applications in new fields are prospected.     

Bacteriophage M13 as a scaffold for preparing conductive polymeric composite fibers

Using biological templates to build one-dimensional functional materials holds great promise in developing nanosized electrical devices, sensors, catalysts, and energy storage units. In this communication, we report a versatile assembly process for the preparation of water-soluble conductive polyaniline (PANi)/M13 composite nanowires by employing the bacteriophage M13 as a template. The surface lysine residues of M13 can be derivatized with carboxylic groups to improve its binding ability to the aniline; the resulting modified M13 is denoted as m-M13. Highly negatively-charged poly(sulfonated styrene) was used both as a dopant acid and a stabilizing agent to enhance the stability of the composite fibers in aqueous solution. A transparent solution of the conductive PANi/m-M13 composite fibers can be readily obtained without any further purification step. The fibers can be easily fabricated into thin conductive films due to their high aspect ratio and good solubility in aqueous solution. This synthesis discloses a unique and versatile way of using bionanorods to produce composite fibrillar materials with narrow dispersity, high aspect ratio, and high processibility, which may have many potential applications in electronics, optics, sensing, and biomedical engineering. This article is published with open access at Springerlink.com     

Recent advances in electrospun carbon nanofibers and their application in electrochemical energy storage

Carbon nanofibers (CNFs) have been widely used in electrochemical energy storage devices because of their excellent conductivities, extremely large surface areas and structural stability. In energy storage devices like rechargeable batteries and supercapacitors, CNFs play multi-functional roles as active electrode materials, conductive additives and substrates for supporting active metal (oxides). Electrospinning offers a low cost and scalable technique to fabricate CNFs and their hybrids with tunable nanostructures. This paper summarizes various design strategies for producing random, aligned and core/shell structured fibers, and elucidates the influences of polymer precursors, processing parameters, conductive additives and catalysts on functional, morphological and structural characteristics of CNFs. The current start-of-the-art developments for applications in Li-ion batteries, supercapacitors, Na-ion batteries, Li–O₂ batteries and Li–S batteries are reviewed. Key issues that affect the electrochemical performance of the electrodes, such as the chemical and atomic structures, electrical conductivities, surface areas and pore size distribution of CNFs, and the particle size, shape and dispersion of metal (oxides) encapsulated in CNFs, are discussed and their solutions suggested. Future prospects on further optimization of the structure and performance, and challenges encountered in large-scale applications of electrospun CNFs are proposed.     

Research progress on electrode materials and electrolytes for supercapacitors北大核心CSCD

Supercapacitors have great potential applications for electronic devices, and energy recyling and storage areas owing to their high power density, long cycle life, high safety and excellent performance at low temperatures. The electrode materials and electrolytes are two key factors that influence their performance. The electrode materials used in supercapacitors include carbon materials such as activated carbons, carbon nanotubes, graphene, carbon nanofibers and carbon nano-onions, metal oxides, conductive polymers and their composites. The electrolytes are aqueous electrolytes, organic electrolytes or ionic liquids. Here research progress on the electrode materials and liquid electrolytes for supercapacitors is summarized, their advantages and disadvantages are analyzed, and new electrode materials and electrolytes are suggested.     

Self-healing flexible/stretchable energy storage devices

During the past decade, flexible/stretchable energy storage devices have garnered increasing attention, with the successful development of wearable electronics. However, due to the repeated deformation accompanied with the electrochemical depletion process, these devices suffer from unavoidable damage, including cracks, crazing, puncture and delamination, which can lead to serious performance degradation or even safety issues. Simultaneously, inspired by biological organs, self-healing capability is found to be a promising approach to address these issues by restoring the mechanical and electrochemical performance. This review first summarizes the structural design and features of various flexible/stretchable energy storage devices, from 1D to 3D configurations. Then, basic concepts and three self-healing mechanisms, including capsule-based systems, vascular-based systems, and intrinsic healing systems are analyzed along with a brief look at existing applications. Then we review all the important parts of state-of-art flexible/stretchable self-healing supercapacitors and batteries including electrodes, electrolytes, substrates and encapsulation. Moreover, a detailed evaluation of methodologies for flexibility, stretchability and self-healing capabilities are described in detail. Finally, the critical challenges and prospects of future promising solutions for self-healing flexible/stretchable energy storage devices or even electronics are provided.     

导电基质纳米复合电极材料的研究进展

在各种能源储存设备中,锂离子电池成为重要的首选储能器件,在便携电子设备、电动车、混合电动车及其它能源存储设备等方面都有广泛应用。如何提高锂离子电池用电极材料的锂离子储存性能,已经成为材料科学与工程领域的热点之一。利用导电基质构建纳米结构复合材料是提高锂离子储存性能的有效途径。简要介绍了碳基和金属基质纳米复合电极材料的研究进展,主要包括材料制备新方法、新工艺、锂离子电池改性及其发展趋势等内容。     

Chemically Integrated Inorganic‐Graphene Two‐Dimensional Hybrid Materials for Flexible Energy Storage Devices

State‐of‐the‐art energy storage devices are capable of delivering reasonably high energy density (lithium ion batteries) or high power density (supercapacitors). There is an increasing need for these power sources with not only superior electrochemical performance, but also exceptional flexibility. Graphene has come on to the scene and advancements are being made in integration of various electrochemically active compounds onto graphene or its derivatives so as to utilize their flexibility. Many innovative synthesis techniques have led to novel graphene‐based hybrid two‐dimensional nanostructures. Here, the chemically integrated inorganic‐graphene hybrid two‐dimensional materials and their applications for energy storage devices are examined. First, the synthesis and characterization of different kinds of inorganic‐graphene hybrid nanostructures are summarized, and then the most relevant applications of inorganic‐graphene hybrid materials in flexible energy storage devices are reviewed. The general design rules of using graphene‐based hybrid 2D materials for energy storage devices and their current limitations and future potential to advance energy storage technologies are also discussed.     

纤维素导电基底及其柔性电子器件的研究进展

纤维素是自然界中含量丰富且可再生、可降解的天然材料。本文综述了物理、化学、生物或相结合的技术对纤维素的影响作用及可制备的纤维素基元材料,例如纤维素纤维、纳米纤维素和纤维素分子。基于纤维素纤维,利用湿法造纸技术可以生产具有高孔隙率的纤维素纸张基底;基于纳米纤维素,利用真空抽滤或涂布等方式可制备具有低表面粗糙度及高透明度的纳米纤维素膜基底;基于纤维素分子,利用涂布或铸涂等方式可生产具有均一的表面形态及高透明度的再生纤维素膜基底。本文进一步分析了常用的导电材料(金属导电材料、聚合物导电材料及碳基导电材料等)及其与纤维素基底结合的方法(涂布、沉积、原位聚合、自组装等),进而可以制备柔韧轻质的纤维素导电基底。基于高性能的纤维素导电基底可以组装柔性电子器件,在光电转化、能量储存及电磁屏蔽等领域展现了广阔的应用前景。总之,利用天然纤维素制备柔性电子器件对于扩大纤维素的应用范围、提升纤维素的利用价值及推动柔性电子器件的进一步发展具有重要意义。      

Advanced Carbon for Flexible and Wearable Electronics

Flexible and wearable electronics are attracting wide attention due to their potential applications in wearable human health monitoring and care systems. Carbon materials have combined superiorities such as good electrical conductivity, intrinsic and structural flexibility, light weight, high chemical and thermal stability, ease of chemical functionalization, as well as potential mass production, enabling them to be promising candidate materials for flexible and wearable electronics. Consequently, great efforts are devoted to the controlled fabrication of carbon materials with rationally designed structures for applications in next‐generation electronics. Herein, the latest advances in the rational design and controlled fabrication of carbon materials toward applications in flexible and wearable electronics are reviewed. Various carbon materials (carbon nanotubes, graphene, natural‐biomaterial‐derived carbon, etc.) with controlled micro/nanostructures and designed macroscopic morphologies for high‐performance flexible electronics are introduced. The fabrication strategies, working mechanism, performance, and applications of carbon‐based flexible devices are reviewed and discussed, including strain/pressure sensors, temperature/humidity sensors, electrochemical sensors, flexible conductive electrodes/wires, and flexible power devices. Furthermore, the integration of multiple devices toward multifunctional wearable systems is briefly reviewed. Finally, the existing challenges and future opportunities in this field are summarized.     

Carbon nanotubes for electronics manufacturing and packaging:from growth to integration

Carbon nanotubes (CNTs) possess excellent electrical, thermal and mechanical properties. They are light in weight yet stronger than most of the other materials. They can be made both highly conductive and semi-conductive. They can be made from nano-sized small catalyst particles and extend to tens of millimeters long. Since CNTs emerged as a hot topic in the early 1990s, numerous research efforts have been spent on the study of the various properties of this new material. CNTs have been proposed as alternative materials of potential excellence in a lot of applications such as electronics, chemical sensors, mechanical sensors/actuators and composite materials, etc. This paper reviews the use of CNTs particularly in electronics manufacturing and packaging
field. The progresses of three most important applications, including CNT-based thermal interface materials, CNT-based interconnections and CNT-based cooling devices are reviewed. The growth and post-growth processing of CNTs for specific applications are introduced and the tailoring of CNTs properties, i.e., electrical resistivity, thermal  conductivity and strength, etc., is discussed with regard to specific application requirement. As the semiconductor industry is still driven by the need of getting smaller and faster, CNTs and the related composite systems as emerging new materials are likely to provide the solution to the future challenges as we make more and more complex electronics devices and systems.     

Nanostructured covalent organic frameworks with elevated crystallization for (electro)photocatalysis and energy storage devices

Nanostructured covalent organic frameworks (COFs) have attracted great attentions over the past few decades due to their unique physical and chemical properties. Crystallization is sought in many application fields since it allows enhancing or even promoting properties of catalysis, energy storage and photoelectric properties. However, the crystallization process of nanostructured COFs remains to be challenging. Synthetic approaches to establish nucleation and elongation growth of COFs for controlling crystallization have drawn substantial amount of attentions. Nanostructured COFs have exhibited significant advantages when applied in (electro)photocatalysis and energy storage devices as well. In this review, recent progress in precisely design strategy of fabricating various nanostructured COFs and their applications as (electro)photocatalyzer and energy storage devices are summarized. After a brief introduction of the design principles, composition and interior architecture, the morphology of nanostructured COFs including porous and mesoporous stacked-layer structure, nanosheet structure, nanorod structure, ordered stripe arrays and various nanocomposites are thoroughly described. Reactions dedicated to crystallization process for two-dimensional (2D) COFs are discussed further. Then, the applications of nanostructured COFs as (electro)photocatalysis and energy storage devices are demonstrated. Finally, the potential advantages and challenges for the synthetic technology of nanostructured COFs materials are particularly discussed. Personal insights into the challenges and opportunities on pursuing topologies as hollow structures, dense spheres, yolk–shell structures were raised to broaden the applications.

     

Mass production of two-dimensional materials beyond graphene and their applications

Nano Research - Two-dimensional (2D) materials are promising candidates in wide applications including energy storage and conversion, sensors, flexible devices, etc. The low-cost production of 2D...     

Materials and Techniques for Implantable Nutrient Sensing Using Flexible Sensors Integrated with Metal–Organic Frameworks

The combination of novel materials with flexible electronic technology may yield new concepts of flexible electronic devices that effectively detect various biological chemicals to facilitate understanding of biological processes and conduct health monitoring. This paper demonstrates single‐ or multichannel implantable flexible sensors that are surface modified with conductive metal–organic frameworks (MOFs) such as copper‐MOF and cobalt‐MOF with large surface area, high porosity, and tunable catalysis capability. The sensors can monitor important nutriments such as ascorbicacid, glycine, l ‐tryptophan (l ‐Trp), and glucose with detection resolutions of 14.97, 0.71, 4.14, and 54.60 × 10^?6 m , respectively. In addition, they offer sensing capability even under extreme deformation and complex surrounding environment with continuous monitoring capability for 20 d due to minimized use of biological active chemicals. Experiments using live cells and animals indicate that the MOF‐modified sensors are biologically safe to cells, and can detect l ‐Trp in blood and interstitial fluid. This work represents the first effort in integrating MOFs with flexible sensors to achieve highly specific and sensitive implantable electrochemical detection and may inspire appearance of more flexible electronic devices with enhanced capability in sensing, energy storage, and catalysis using various properties of MOFs.     

Hollow MXene Spheres and 3D Macroporous MXene Frameworks for Na‐Ion Storage

2D transition metal carbides and nitrides, named MXenes, are attracting increasing attentions and showing competitive performance in energy storage devices including electrochemical capacitors, lithium‐ and sodium‐ion batteries, and lithium–sulfur batteries. However, similar to other 2D materials, MXene nanosheets are inclined to stack together, limiting the device performance. In order to fully utilize MXenes' electrochemical energy storage capability, here, processing of 2D MXene flakes into hollow spheres and 3D architectures via a template method is reported. The MXene hollow spheres are stable and can be easily dispersed in solvents such as water and ethanol, demonstrating their potential applications in environmental and biomedical fields as well. The 3D macroporous MXene films are free‐standing, flexible, and highly conductive due to good contacts between spheres and metallic conductivity of MXenes. When used as anodes for sodium‐ion storage, these 3D MXene films exhibit much improved performances compared to multilayer MXenes and MXene/carbon nanotube hybrid architectures in terms of capacity, rate capability, and cycling stability. This work demonstrates the importance of MXene electrode architecture on the electrochemical performance and can guide future work on designing high‐performance MXene‐based materials for energy storage, catalysis, environmental, and biomedical applications.     

Rational design of MXene-based films for energy storage: Progress,prospects

Two-dimensional (2D) transition metal carbides, nitrides, and carbonitrides (MXenes) have been synthesized and developed into a wide range of applications including energy storage, optoelectronics, electromagnetic interference shielding, biomedicine, and sensors, etc. Compared to other 2D materials, MXenes possess a unique set of properties such as superior mechanical strength, outstanding hydrophily, and excellent dispersion quality, making them particularly suitable for fabricating films/membranes featuring designed microstructures and tunable nanochannels. 2D MXene-based films (MBFs) have demonstrated excellent ion storage, electron transport and ionic selectivity properties for electrochemical energy storage and have received enormous interest in recent years. Compared with conventional electrode materials and structures, MBFs show great advantages in the aspects of flexibility, tailorability and functionality, which are suitable for flexible, portable, and highly integrated energy storage systems. This review summarizes recent advances and well-developed strategies of the MBFs design and fabrication toward applications of metal-ion batteries (MIBs, including Li, Na, K-ions), lithium-sulfur (Li-S) batteries and supercapacitors (SCs). Special attentions are given to the design principles of MBFs based microstructures, inter-layer nanochannels and in-plane nanochannels for energy storage. Finally, the current challenges and promising perspectives of the MBFs for energy storage devices are presented.     

Intercalation of Layered Materials from Bulk to 2D

Intercalation in few‐layer (2D) materials is a rapidly growing area of research to develop next‐generation energy‐storage and optoelectronic devices, including batteries, sensors, transistors, and electrically tunable displays. Identifying fundamental differences between intercalation in bulk and 2D materials will play a key role in developing functional devices. Herein, advances in few‐layer intercalation are addressed in the historical context of bulk intercalation. First, synthesis methods and structural properties are discussed, emphasizing electrochemical techniques, the mechanism of intercalation, and the formation of a solid‐electrolyte interphase. To address fundamental differences between bulk and 2D materials, scaling relationships describe how intercalation kinetics, structure, and electronic and optical properties depend on material thickness and lateral dimension. Here, diffusion rates, pseudocapacity, limits of staging, and electronic structure are compared for bulk and 2D materials. Next, the optoelectronic properties are summarized, focusing on charge transfer, conductivity, and electronic structure. For energy devices, opportunities also emerge to design van der Waals heterostructures with high capacities and excellent cycling performance. Initial studies of heterostructured electrodes are compared to state‐of‐the‐art battery materials. Finally, challenges and opportunities are presented for 2D materials in energy and optoelectronic applications, along with promising research directions in synthesis and characterization to engineer 2D materials for superior devices.