Advances on Emerging Materials for Flexible Supercapacitors: Current Trends and Beyond

The progressive size reduction of electronic components is experiencing bottlenecks in shrinking charge storage devices like batteries and supercapacitors, limiting their development into wearable and flexible zero‐pollution technologies. The inherent long cycle life, rapid charge–discharge patterns, and power density of supercapacitors rank them superior over other energy storage devices. In the modern market of zero‐pollution energy devices, currently the lightweight formula and shape adaptability are trending to meet the current requirement of wearables. Carbon nanomaterials have the potential to meet this demand, as they are the core of active electrode materials for supercapacitors and texturally tailored to demonstrate flexible and stretchable properties. With this perspective, the latest progress in novel materials from conventional carbons to recently developed and emerging nanomaterials toward lightweight stretchable active compounds for flexi‐wearable supercapacitors is presented. In addition, the limitations and challenges in realizing wearable energy storage systems and integrating the future of nanomaterials for efficient wearable technology are provided. Moreover, future perspectives on economically viable materials for wearables are also discussed, which could motivate researchers to pursue fabrication of cheap and efficient flexible nanomaterials for energy storage and pave the way for enabling a wide‐range of material‐based applications.     

The Cathode Choice for Commercialization of Sodium‐Ion Batteries: Layered Transition Metal Oxides versus Prussian Blue Analogs

With the unprecedentedly increasing demand for renewable and clean energy sources, the sodium‐ion battery (SIB) is emerging as an alternative or complementary energy storage candidate to the present commercial lithium‐ion battery due to the abundance and low cost of sodium resources. Layered transition metal oxides and Prussian blue analogs are reviewed in terms of their commercial potential as cathode materials for SIBs. The recent progress in research on their half cells and full cells for the ultimate application in SIBs are summarized. In addition, their electrochemical performance, suitability for scaling up, cost, and environmental concerns are compared in detail with a brief outlook on future prospects. It is anticipated that this review will inspire further development of layered transition metal oxides and Prussian blue analogs for SIBs, especially for their emerging commercialization.     

Rational Design of Nanostructured Electrode Materials toward Multifunctional Supercapacitors

As an intermediate step during energy usage, supercapacitors with superior power density, long‐term cycling stability, and moderate energy density have attracted immense interest as a facile route to use energy in a clean, efficient, and versatile manner in smart grid applications, as well as portable devices and other applications. Currently, the major drawback of supercapacitors is the low energy density. Electrode materials are the key components determining the cell performance. Great research efforts are made to develop nanostructured electrode materials with high performance. On the other hand, integrating supercapacitors with other applications have led to the emergence of many new types of multifunctional supercapacitors, which are attractive for a myriad of applications. The current understanding on charge/discharge mechanisms of electric double layer capacitors and pseudo‐capacitors is discussed along with recent development in designing nanostructured electrode materials by structure/morphology engineering, doping, and crystal structure controlling. Achievements in multifunctional supercapacitors like flexible supercapacitors, all‐solid‐state supercapacitors, self‐healing supercapacitors, electrochromic supercapacitors, self‐chargeable supercapacitors, and supercapacitors integrated with sensors are illustrated. Finally, opportunities and challenges in developing high performance and multifunctional supercapacitors are proposed.     

Self-charging power textiles integrating energy harvesting triboelectric nanogenerators with energy storage batteries/supercapacitors

Lightweight and flexible self-charging power systems with synchronous energy harvesting and energy storage abilit-ies are highly desired in the era of the internet of things and artificial intelligences,which can provide stable,sustainable,and autonomous power sources for ubiquitous,distributed,and low-power wearable electronics.However,there is a lack of compre-hensive review and challenging discussion on the state-of-the-art of the triboelectric nanogenetor (TENG)-based self-charging power textiles,which have a great possibility to become the future energy autonomy power sources.Herein,the recent pro-gress of the self-charging power textiles hybridizing fiber/fabric based TENGs and fiber/fabric shaped batteries/supercapacitors is comprehensively summarized from the aspect of textile structural designs.Based on the current research status,the key bottle-necks and brighter prospects of self-charging power textiles are also discussed in the end.It is hoped that the summary and pro-spect of the latest research of self-charging power textiles can help relevant researchers accurately grasp the research progress,focus on the key scientific and technological issues,and promote further research and practical application process.     

Halide Perovskite Materials for Energy Storage Applications

Halide perovskites, traditionally a solar‐cell material that exhibits superior energy conversion properties, have recently been deployed in energy storage systems such as lithium‐ion batteries and photorechargeable batteries. Here, recent progress in halide perovskite‐based energy storage systems is presented, focusing on halide perovskite lithium‐ion batteries and halide perovskite photorechargeable batteries. Halide‐perovskite‐based supercapacitors and photosupercapacitors are also discussed. The photorechargeable batteries and photorechargeable supercapacitors employ solar energy to photocharge the battery; this saves energy and improves device portability. These lightweight, integrated halide perovskite‐based systems, which are pertinent to electric vehicles and portable electronic devices, are reviewed in detail. Suggestions on future research into the design of halide‐perovskite‐based energy storage materials are also given. This review provides a foundation for the development of integrated lightweight energy conversion and storage materials.     

Non-van der Waals 2D Materials for Electrochemical Energy Storage

The development of advanced electrode materials for the next generation of electrochemical energy storage (EES) solutions has attracted profound research attention as a key enabling technology toward decarbonization and electrification of transportation. Since the discovery of graphene's remarkable properties, 2D nanomaterials, derivatives, and heterostructures thereof, have emerged as some of the most promising electrode components in batteries and supercapacitors owing to their unique and tunable physical, chemical, and electronic properties, commonly not observed in their 3D counterparts. This review particularly focuses on recent advances in EES technologies related to 2D crystals originating from non-layered 3D solids (non-van der Waals; nvdW) and their hallmark features pertaining to this field of application. Emphasis is given to the methods and challenges in top-down and bottom-up strategies toward nvdW 2D sheets and their influence on the materials’ features, such as charge transport properties, functionalization, or adsorption dynamics. The exciting advances in nvdW 2D-based electrode materials of different compositions and mechanisms of operation in EES are discussed. Finally, the opportunities and challenges of nvdW 2D systems are highlighted not only in electrochemical energy storage but also in other applications, including spintronics, magnetism, and catalysis.     

Nanoarchitectured Design of Vertical-Standing Arrays for Supercapacitors: Progress,Challenges, and Perspectives

Vertical-standing arrays have aroused great enthusiasm as electrode materials for supercapacitors in recent years owing to their structural and compositional characteristics. Although significant efforts have been made in the construction of vertical-standing arrays with tailored compositions and architectures, an in-depth understanding of the relevant structure–activity relationships has not yet been reviewed in detail. Herein, recent important progress in controllably synthesizing vertical-standing arrays as well as their application as supercapacitors is reviewed. Afterward, promising strategies to improve the electrochemical performance of vertical-standing arrays are discussed. Finally, the challenges and possible directions for developing vertical-standing arrays with outstanding performance are outlined. This review provides important guidelines for designing and regulating vertical-standing arrays and constructing desirable electrode materials for future electrochemical energy storage.     

Non-Monotonic Capacitance Change of Layered Ti3C2Tx MXene Film Structures under Increasing Compressive Stress

The progress in advanced electronic devices has imposed a great demand for developing flexible electrochemical power devices, which requires a comprehensive understanding of the mechanical–electrochemical coupling behavior of various energy storage materials. Unlike a monotonic capacitance increase of carbon-based double-layer supercapacitors, MXene-based flexible supercapacitors demonstrate a non-monotonic, i.e., “increase-then-decrease” capacitance behavior under the pressure range of 8488 kPa. This non-monotonic capacitance response to pressure is intrinsic to the MXene film as its charge storage is primarily determined by the surface activity, which can be readily affected by pressure-induced dissociation of functionalities, as well as the charge transporting kinetics as limited by the inherent layered structure. The findings described in this study not only expand the knowledge of mechanical–electrochemical coupling to layered MXenes under pressure, but also give a vital design guideline for flexible/stretchable MXene-based energy storage devices or other electronics.     

III型聚合物超电容器国外研究进展

评述了国外在III型聚合物超电容器方面的研究进展。目前,国外一些主要研究单位已经进展到研制模型电容器的阶段。III型聚合物超电容器所用的导电高分子主要包括聚噻吩衍生物类,如:聚-3-(4-氟苯基)噻吩、聚二噻吩[3,4-b;3,4-d]噻吩,聚苯胺类等。在用这些聚合物所组装的超电容器中,能量密度最大可达68 Wh/kg,功率密度最大可达30.5?03 W/kg。     

碳化硅电力电子器件及其制造工艺新进展

评述了各种碳化硅电力电子器件研究开发的最新进展及其发展前景,指出碳化硅的优势不仅仅限于能提高功率开关器件的电压承受能力、高温承受能力和兼顾频率与功率的能力,还在于能大幅度降低器件的功率损耗,使电力电子技术的节能优势得以更加充分地发挥.针对碳化硅材料的特殊性和实现碳化硅器件卓越性能的需要,分析了器件工艺当前亟待解决的问题.     

MXenes and Their Derivatives for Advanced Solid-State Energy Storage Devices

Solid-state energy storage devices (SSESDs) are believed to significantly improve safety, long-term electrochemical/thermal stability, and energy/power density as well as reduce packaging demands, showing the huge application potential in large-scale energy storage. Nevertheless, some key issues like low ionic conductivities, poor interface contact, and dendrites growth limit the practical application of SSESDs. In recent years, MXenes for SSESDs have received reassuring advances on account of unique parameters. Nevertheless, overall reviews about the subject are seldom. In this review, current advances of MXenes and their derivatives in solid-state Li–metal, Li-ion, Li–I/S, Na-ion, Zn–air, Zn–metal batteries, and supercapacitors in cathode/anode optimization, interface medication, and electrolyte fillers, etc., are comprehensively reviewed. First of all, essential principles of MXenes are shown, such as precursors, etching/delamination strategies, as well as superior properties for energy storage systems. Meanwhile, the classification and evaluation parameters of solid-state electrolytes are summarized. Subsequently, the application, modification mechanism, and design strategy of MXenes for boosting electrochemical behaviors of SSESDs are systematically reviewed and discussed. At last, perspectives and challenges about the future construction strategies of MXenes for SSESDs are recommended. This review shall assist scientists design and build advanced SSESDs with superior energy density along with safety.     

Electroactive polymer-based devices for e-textiles in biomedicine.

This paper describes the early conception and latest developments of electroactive polymer (EAP)-based sensors, actuators, electronic components, and power sources, implemented as wearable devices for smart electronic textiles (e-textiles). Such textiles, functioning as multifunctional wearable human interfaces, are today considered relevant promoters of progress and useful tools in several biomedical fields, such as biomonitoring, rehabilitation, and telemedicine. After a brief outline on ongoing research and the first products on e-textiles under commercial development, this paper presents the most highly performing EAP-based devices developed by our lab and other research groups for sensing, actuation, electronics, and energy generation/storage, with reference to their already demonstrated or potential applicability to electronic textiles.     

A Progress Report on Metal–Sulfur Batteries

Nonaqueous conversion‐reaction sulfur chemistry has been attracting increasing attention over the past decade for the development of next‐generation lithium‐based batteries. Li–S batteries are currently approaching a nexus stage from lab‐scale experiments to possible pragmatic applications. Inspired by the success of Li–S chemistry, other metal–sulfur batteries with a variety of metallic anodes, such as sodium, potassium, magnesium, calcium, and aluminum, have also started to attract attention. In comparison to lithium, Na, Mg, Al, K, and Ca are naturally more abundant and affordable. The Na‐S, Mg‐S, Al‐S, K‐S, and Ca‐S battery systems provide a great potential for improving the volumetric energy density of sulfur‐based batteries. The multivalent metal‐sulfur systems, Mg‐S, Al‐S, and Ca‐S, offer better safety features as well. However, the research and development on Na‐S, Mg‐S, Al‐S, K‐S, and Ca‐S batteries is far behind the Li–S system due to many critical challenges. In this progress report, the fundamental principles of various metal–sulfur chemistries are first presented and compared. Then, the historical progress, recent advances, and key challenges of the Li–S, Na‐S, Mg‐S, Al‐S, K‐S, and Ca‐S systems are summarized and discussed. Finally, future efforts and directions for both the fundamental and practical research are prospected.     

The lte/sae trial initiative: taking lte/sae from specification to rollout - LTE part II: 3GPP release 8

Now that the standards for LTE/SAE are functionally frozen, we consider the activities needed to implement the technology and prepare it for commercial rollout: prototyping, interoperability testing, and field trials. The LSTI is a global initiative of operators and vendors who are coordinating and reporting progress on these activities to ensure that everyone has a realistic understanding of what performance and functionality to expect from LTE, and the readiness of the technology for commercial roll out. The LSTI aims to accelerate commercialization of LTE/SAE by fostering technology alignment across all key vendor participants. This article provides an overview of the activities and gives an update on the results published so far.     

The applications of carbon nanomaterials in fiber-shaped energy storage devices

As a promising candidate for future demand,fiber-shaped electrochemical energy storage devices,such as supercapacitors and lithium-ion batteries have obtained considerable attention from academy to industry.Carbon nanomaterials,such as carbon nanotube and graphene,have been widely investigated as electrode materials due to their merits of light weight,flexibility and high capacitance.In this review,recent progress of carbon nanomaterials in flexible fiber-shaped energy storage devices has been summarized in accordance with the development of fibrous electrodes,including the diversified electrode preparation,functional and intelligent device structure,and large-scale production of fibrous electrodes or devices.     

Current Technology of Supercapacitors: A Review

A supercapacitor is a solid-state device that can store electrical energy in the form of charges. It represents an advancement in the field of energy storage, as it overcomes many of the shortcomings of batteries. This paper presents an overview of the various types of supercapacitors, electrode materials, and electrolytes, and the future of supercapacitors. Due to their high storage capacity, supercapacitors are commonly used in portable electronic devices such as MP3 players and mobile phones, and in hybrid vehicles and other applications. In electrical and hybrid vehicles, supercapacitors are increasingly used as provisional energy storage for regenerative braking. Various materials are used in electrodes to boost the performance of the supercapacitor. This review presents details regarding the materials and electrolyte, and the improvements in the field of supercapacitors.     

Capacitive Enhancement Mechanisms and Design Principles of High‐Performance Graphene Oxide‐Based All‐Solid‐State Supercapacitors

Graphene oxide (GO)‐based all‐solid‐state supercapacitors (GO‐A3Ss) are superior over liquid electrolyte‐based supercapacitors and capable of being integrated on a single chip in various geometry shapes for the use of future smart wearable electronics field as a fast energy storage device, but their capacitance need to be improved. Here, a new approach has been developed for enhancing the capacitive capability of the supercapacitors through molecular dynamics simulations with the first‐principle input. A theoretical model of charge storage is developed to understand the unique capacitive enhancement mechanism and to predict the capacitance of the GO‐A3Ss, which agrees well with the experimental observations. A novel supercapacitor with GO and reduced graphene oxide (rGO) alternatively layered structures is designed based on the model, and its energy density is the highest among conventional supercapacitors using liquid electrolytes and all‐solid‐state supercapacitors using aerogels or hydrogels as the solid‐state electrolyte. Based on the predictions, two new types of high‐performance GO/rGO multilayered capacitors are proposed to meet different practical applications. The results of this work provide an approach for the design of high‐performance all‐solid‐state supercapacitors based on GO and rGO materials.     

Emerging Design Strategies Toward Developing Next-Generation Implantable Batteries and Supercapacitors

In recent years, the development of implantable bioelectronics has garnered significant attention. With the continuous advancement of IoT and information technology, implantable bioelectronics can be utilized more effectively for health monitoring to enhance treatment outcomes, reduce healthcare costs, and improve quality of life. Implantable energy storage devices have been widely studied as critical components for energy supply. Conventional power sources are bulky, inflexible, and potentially contain materials that are dangerous to the body. Meanwhile, human tissues are soft, flexible, dynamic, and closed, which puts new requirements on energy storage devices to improve the safety, stability, and matching of implantable batteries or supercapacitors. Herein, recent advances in state-of-the-art nonconventional power options for implantable electronics, specifically biocompatible, miniaturized, stretchable/deformable, biodegradable/bioresorbable, edible, and injectable energy storage devices, are reviewed in this paper. The material strategy and architectural design of the next-generation implantable energy storage device are discussed, including the selection principle of electrolytes, the all-in-one structure design strategy, and the way to realize self-charging. Finally, the challenges and prospects of emerging design strategies toward developing next-generation implantable batteries and supercapacitors for the future are put forward.     

硫系玻璃及其在红外光学系统中的应用

硫系玻璃是指以元素周期表VIA族中S,Se,Te为主并引入一定量的其它类金属元素所形成的玻璃,它具有优良的透中红外和极佳的消热差性能,被视为新一代温度自适应红外光学系统核心透镜材料,可广泛应用于军用(夜视枪瞄、红外肩扛导弹、战机夜视巡航等)和民用(汽车夜视、安防监控等)红外光学系统中。回顾了硫系玻璃发展历程,从商业硫系玻璃产品、制备工艺技术、玻璃精密模压技术及在红外光学系统应用4个方面总结了硫系玻璃目前的发展现况,并对其发展前景进行了展望。     

Recent Advances in Non‐Noble Bifunctional Oxygen Electrocatalysts toward Large‐Scale Production

The oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are crucial reactions in energy conversion and storage systems including fuel cells, metal–air batteries, and electrolyzers. Developing low‐cost, high‐efficiency, and durable non‐noble bifunctional oxygen electrocatalysts is the key to the commercialization of these devices. Here, based on an in‐depth understanding of ORR/OER reaction mechanisms, recent advances in the development of non‐noble electrocatalysts for ORR/OER are reviewed. In particular, rational design for enhancing the activity and stability and scalable synthesis toward the large‐scale production of bifunctional electrocatalysts are highlighted. Prospects and future challenges in the field of oxygen electrocatalysis are presented.