Natural Cellulose Derived Nanocomposites as Anodic Materials for Lithium‐Ion Batteries

Bio‐inspired synthetic method provides an effective shortcut to fabricate functional nanostructured materials with specific morphologies and designed functionalities. Natural cellulose substances (e. g., commercial laboratory cellulose filter paper) possesses unique three‐dimensionally cross‐linked porous structures and abundant functional groups for the functional modification on the surfaces. The deposition of metal oxide gel film on the surfaces of the cellulose nanofibers is facilely to be achieved through the surface sol‐gel process, resulting in metal oxide replicas of the initial cellulose substance or metal‐oxide/carbon nanocomposites. Moreover, the as‐deposited metal oxide gel films coated on the cellulose fiber surfaces provide ideal platforms for the further formation of specific functional assemblies, and eventually to the corresponding nanocomposite materials. Based on this methodology, various nanostructured composites were prepared and employed as anodic materials for lithium‐ion batteries, including metal‐oxides‐based (such as SnO₂, TiO₂, MoO₃, Fe_xO_y, and SiO₂) and Si‐based composites, as summarized in this personal account. Benefiting from the unique hierarchically porous network structures and the synergistic effects among the composite components of the anodic materials, the transfer of electrons/ions is accelerated and the structural stability of the electrode is enhanced, leading to the improved lithium storage performances and promoted cycling stability.     

石墨炔纳米材料的制备及在电化学能源中的应用

石墨炔纳米材料的制备与应用是石墨炔材料研究的重要方向, 通过对其纳米结构进行设计与优化, 可以提高石墨炔材料及其杂化结构的性能, 拓展其在能源储存与转换领域的应用. 本综述介绍了不同形貌和结构的石墨炔基纳米材料, 如纳米墙、 纳米片、 纳米薄膜等结构. 阐述了不同结构特征的石墨炔基纳米材料在电化学储能器件以及电化学能源催化中的应用, 同时也探讨了石墨炔不同纳米形貌和结构在能源应用领域快速发展的机遇及所面临的挑战.     

Design of Functional Carbon Composite Materials for Energy Conversion and Storage

The carbon composite materials have been a research hotspot in the fields of catalysis, energy conversion and so on, because of their features of large structure and morphology variety, good chemical and electrochemical stability, and high electronic conductivity, large specific surface area and rich active sites. This paper summarizes some research progress of carbon composite materials, including assembly methodologies, their structure regulation, properties, and related applications. Moreover, the current challenges and the prospects of these materials are also discussed.     

2020 Roadmap on Carbon Materials for Energy Storage and Conversion

Carbon is a simple, stable and popular element with many allotropes. The carbon family members include carbon dots, carbon nanotubes, carbon fibers, graphene, graphite, graphdiyne and hard carbon, etc. They can be divided into different dimensions, and their structures can be open and porous. Moreover, it is very interesting to dope them with other elements (metal or non‐metal) or hybridize them with other materials to form composites. The elemental and structural characteristics offer us to explore their applications in energy, environment, bioscience, medicine, electronics and others. Among them, energy storage and conversion are extremely attractive, as advances in this area may improve our life quality and environment. Some energy devices will be included herein, such as lithium‐ion batteries, lithium sulfur batteries, sodium‐ion batteries, potassium‐ion batteries, dual ion batteries, electrochemical capacitors, and others. Additionally, carbon‐based electrocatalysts are also studied in hydrogen evolution reaction and carbon dioxide reduction reaction. However, there are still many challenges in the design and preparation of electrode and electrocatalytic materials. The research related to carbon materials for energy storage and conversion is extremely active, and this has motivated us to contribute with a roadmap on ‘Carbon Materials in Energy Storage and Conversion’.     

石墨烯化聚合物:一种兼具电子和离子传输通道的三维富碳高分子能源材料

近年来,用于电化学能源存储和转化的石墨烯材料,得到了研究者们越来越多的关注。但是,这些石墨烯材料不同于严格定义的单原子碳层结构,往往具有孔洞、杂原子和化学官能团等缺陷结构。由于制备方法的不同,缺陷结构各不相同,其电化学性能也表现各异。结构分析表明,这类材料是由类似石墨烯片段的单元与聚合物链共价连接而成,使其具有石墨烯和聚合物的双重特性,我们称之为石墨烯化聚合物。由小分子通过自下而上的方法制备的多孔聚合物,也可以通过进一步热交联等方法,使其形成包含石墨烯片段单元与聚合物链的化学结构。这些材料与石墨烯衍生材料一起组成了石墨烯化聚合物的整个谱系;这个谱系涵盖了由聚合物到石墨烯的过渡区。更重要的是,这类材料特殊的结构与性质,使其成为一种兼具电子和离子传输通道的三维富碳高分子材料,非常适合作为电极材料应用于电化学能源存储和转化,这为我们深入研究储能器件中电极材料的结构与性能的相关关系提供了很好的材料平台。     

Recent Advances in Two-dimensional Materials for Electrochemical Energy Storage and Conversion

With the increased energy demand,developing renewable and clean energy technologies becomes more and more significant to mitigate climate warming and alleviate the environmental pollution.The key point is design and synthesis of low cost and efficient materials for a wide variety of electrochemical reactions.Over the past ten years,two-dimensional(2D)nanomaterials that graphene represents have been paid much attention as a class of the most promising candidates for heterogeneous electrocatalysts in electrochemical storage and conversion.Their unique properties,such as good chemical stability,good flexibility,and good electronic properties,along with their nanosized thickness and large specific area,make them exhibit comprehensively good performances for energy storage and conversion.Here,we present an overview on the recent advances in electrochemical applications of graphene,graphdiyne,transition metal dichalcogenides(TMDs),and MXenes for supercapacitors(SCs),oxygen reduction reaction(ORR),and hydrogen evolution reaction(HER).     

2D MXenes Nanosheets for Advanced Energy Conversion and Storage Devices: Recent Advances and Future Prospects

Since the initial MXenes were discovered in 2011, several MXene compositions constructed using combinations of various transition metals have been developed. MXenes are ideal candidates for different applications in energy conversion and storage, because of their unique and interesting characteristics, which included good electrical conductivity, hydrophilicity, and simplicity of large-scale synthesis. Herein, we study the current developments in two-dimensional (2D) MXene nanosheets for energy storage and conversion technologies. First, we discuss the introduction to energy storage and conversion devices. Later, we emphasized on 2D MXenes and some specific properties of MXenes. Subsequently, research advances in MXene-based electrode materials for energy storage such as supercapacitors and rechargeable batteries is summarized. We provide the relevant energy storage processes, common challenges, and potential approaches to an acceptable solution for 2D MXene-based energy storage. In addition, recent advances for MXenes used in energy conversion devices like solar cells, fuel cells and catalysis is also summarized. Finally, the future prospective of growing MXene-based energy conversion and storage are highlighted.     

烯碳纤维基能源器件的研究进展

纤维状能源器件的研究极大地推动了可穿戴电子设备的快速发展。烯碳纤维主要包括碳纳米管纤维和石墨烯纤维,其微观组成单元具有独特的碳碳共轭分子形态,宏观结构具有高度可调控性,表现出高的比强度、优良的导电性和导热性、以及良好的机械柔韧性等,被广泛应用于先进能源器件的研究和开发,有效促进了柔性可穿戴电子器件的发展。本文综述了烯碳纤维基能源器件包括能量转换和储能器件等的研究和应用进展,具体介绍了烯碳纤维基太阳能电池、湿气发电机、热电发电机、超级电容器以及电化学电池等的最新成果,重点讨论了烯碳纤维基能源器件的制备方法和可穿戴应用,分析了烯碳纤维基储能及能量转换器件面临的问题和挑战,期望能够为未来高性能纤维基可穿戴能源器件的发展提供有价值的研究思路。     

下一代能源存储技术及其关键电极材料

由于能源危机与环境问题,全球能源的消耗正逐渐从传统化石能源转向其它清洁高效能源。高效清洁能源的存储是电动汽车和智能电网的关键技术,对新能源、新材料和新能源汽车国家战略新兴产业的发展具有重要意义。锂离子电池是目前广泛应用的一种能源存储器件。电动汽车和智能电网对能量密度、功率密度、循环寿命和成本等方面的要求越来越高,传统的锂离子电池面临巨大挑战,发展下一代能源存储技术迫在眉睫。高能量密度的锂硫电池和锂空气电池,低成本、高安全性的室温钠离子电池受到了越来越多的关注。本文简要总结了近年来锂硫电池、锂空气电池和钠离子电池及其关键电极材料的研究进展,并对这些新型能源存储技术存在的问题和未来的前景做出了分析和展望。     

Energy Storage Materials Synthesized from Ionic Liquids

The advent of ionic liquids (ILs) as eco‐friendly and promising reaction media has opened new frontiers in the field of electrochemical energy storage. Beyond their use as electrolyte components in batteries and supercapacitors, ILs have unique properties that make them suitable as functional advanced materials, media for materials production, and components for preparing highly engineered functional products. Aiming at offering an in‐depth review on the newly emerging IL‐based green synthesis processes of energy storage materials, this Review provides an overview of the role of ILs in the synthesis of materials for batteries, supercapacitors, and green electrode processing. It is expected that this Review will assess the status quo of the research field and thereby stimulate new thoughts and ideas on the emerging challenges and opportunities of IL‐based syntheses of energy materials.     

石墨烯基纤维储能器件的研究进展与展望

随着小型化、可穿戴等特征的智能电子以及物联网传感设备的发展,新型纤维状柔性化、小型化电化学储能器件已成为重要的研究方向。同时,对纤维材料和柔性储能器件的性能提出了更高的要求,如可任意弯折、可拉伸、可折叠、高储能密度等。石墨烯纤维具有独特的结构、优异的导电性、良好机械性能和电化学性质,已证明了是一种极具前景、高性能的新型纤维状柔性储能材料。目前,研究者已开发了多种石墨烯基纤维微观结构的调控策略来进一步改进其性能。本文首先系统总结了石墨烯基纤维的制备方法和其性能提升的策略,然后详细讨论其在柔性化纤维状超级电容器、金属离子电池、热电发电机、太阳能电池和相变材料等储能领域中的最新应用进展。最后,对石墨烯基纤维在能源存储和转换领域中存在的挑战和机会进行了展望。     

储能材料的模拟与设计

综述了近年来常用的计算模拟方法, 如第一原理计算, 分子动力学和蒙特-卡罗模拟. 介绍了应用这些方法在锂离子电池材料和储氢材料等储能材料研究中取得的成果和最新的进展, 展望了计算材料学和材料设计学在该领域中的应用前景.     

Cellulose as recyclable organocatalyst for ipso-hydroxylation of arylboronic acids

Cellulose catalyzed oxidative hydroxylation of aryl and hetero-arylboronic acids to the corresponding phenols under metal and base free strategy has been demonstrated. The sustainable ipso-hydroxylation takes place using hydrogen peroxide as an oxidant in water under mild condition in shorter period of time. Interestingly, easy recovery and reusability of heterogeneous catalyst without significant loss in catalytic yield makes the protocol environmentally benign.     

Piezoelectric Nanogenerator Based on Electrospun Cellulose Acetate/Nanocellulose Crystal Composite Membranes for Energy Harvesting Application

Nanogenerators, as the typical conversion of mechanical energy to electrical energy devices, have great potential in the application of providing sustainable energy sources for powering miniature devices. In this work, cellulose acetate/cellulose nanocrystal(CA/CNC) composite nanofiber membranes were prepared by electrospinning method and then utilized to manufacture a flexible pressure-driven nanogenerator. The addition of CNC not only increased the content of piezoelectric cellulose I crystallization but also strengthened the mechanical deformation of the nanofiber membranes, which could greatly enhance the piezoelectric performance of CA/CNC composite membranes. The CA/CNC composite nanofiber membrane with 20%(mass fraction) of CNC(CA/CNC-20%) showed optimal piezoelectric conversion performance with the output voltage of 1.2 V under the force of 5 N(frequency of 2 Hz). Furthermore, the output voltage of the CA/CNC-20% nanogenerator device exhibited a linear relationship with applied impact force, indicating the great potential in pressure sensors.     

基于微生物作为智能模板的电催化剂制备与应用研究进展

通过电催化实现可再生能源的存储与转化对于改善能源结构、保护生态环境、实现碳达峰和碳中和的国家战略具有重大意义。而开发低成本、高效的电催化剂成为全世界科学家共同面对的挑战。微生物在自然界中广泛存在,具有结构、组成和代谢丰富的特点,可以成为电催化剂的模板以及碳、磷、硫等非金属元素以及金属元素的来源,而且具有无毒、生产可重复性好、易于规模化等优点,已成为电催化剂制备的新趋势。对此,本文综述了微生物“智能”引导制备电催化剂的发展及在电催化析氢(HER)、电催化析氧(OER)、氧还原反应(ORR)、二氧化碳还原(CO₂RR)、锂电池(LBs)等领域的应用现状。希望有助于推动微生物代谢与催化剂微纳结构关系以及与催化反应的构效关系的深入理解,最后针对这类材料的问题挑战及其未来发展方向进行了探讨与展望。     

Graphdiyne Based Atomic Catalyst:an Emerging Star for Energy Conversion

Atomic catalysts(Acs)consisting of zero-valent metal atoms anchored on supporting materials have shown promising potentials in catalysis and energy conversion due to their higher atomic utilization,higher selectivity,activity and durability toward target reactions.However,traditional single-atom catalysts are mainly composed of clusters of metal atoms,which cannot effectively solve the problems of easy migration and aggregation of metal atoms.Besides,the traditional synthesis methods still lack breakthroughs in improving the stability and accurately controlling the chemical structure and charge distribution of metal atoms,which seriously limits the understanding of structure-activity relationship and catalytic mechanism in the catalytic reaction process at the atomic level.Graphdiyne(GDY)based Acs are stabilized by incomplete charge transfer between metal atoms and supporting materials,resolving the easy migration and aggregation of traditional single atomic catalysts,which have been regarded as the next generation of catalysts.This review will start with the overview of the synthesis methods for precisely anchoring of different zero-valent transition metal atoms(e.g.,Ni,Fe,Mo and Cu)and noble metal atoms(e.g.,Pd and Ru),followed by focusing on the recent advances in the researches of the Acs toward a series of important reactions for energy conversion technologies,including the electrochemical water splitting(EWS),nitrogen reduction reaction(NRR),oxygen reduction reaction(ORR)and others.Finally,the review concludes with a perspective highlighting the promises and challenges in the further development of Acs.     

天然产物色胺酮及其衍生物的仿生合成

以药用植物体内存在的生物合成前体吲哚醌和邻氨基苯甲酸为反应物,用POCl3作催化剂,仿生合成了天然产物色胺酮(1),结构表征结果与标准品一致.该反应所用原料易得,避免了使用较昂贵的靛红酸酐,适合实验室小规模简便合成.采用此方法合成了14个色胺酮衍生物,可见其具有广泛的适应性.     

基于纤维素的气凝胶材料

纤维素是自然界中储量最为丰富的一种天然高分子。作为继无机气凝胶和合成聚合物气凝胶之后的第三代气凝胶,纤维素基气凝胶材料兼具绿色可再生的纤维素材料和多孔气凝胶材料两者的优点,成为纤维素材料研究与应用中的一个热点。本文梳理了纤维素基气凝胶材料的发展脉络,综述了纤维素基气凝胶材料的研究进展。重点对纤维素基气凝胶的制备方法进行了总结,包括基于含水溶剂和无水溶剂的纤维素直接溶解法及源自植物纤维素和细菌纤维素的纤维素纳米纤维的水相分散法。介绍了纤维素基气凝胶力学性能的提高和功能性开发的最新研究结果。最后对纤维素基气凝胶材料的发展前景和研究方向进行了展望。     

Synthesis and Characterization of Storage Energy Materials Prepared from Nano-crystalline Cellulose/Polyethylene Glycol

The development and the application of phase change materials (PCMs) as a new kind of materials have attracted both scientific and industrial interest1-4. According to the patterns of phase conversion, commonly PCMs are divided into solid-liquid phase cha…     

纤维素制备渗氮炭材料用于脱除烟气中的SO_2

以纤维素为原料制备了孔结构发达和含氮量较高的渗氮炭材料,并将其应用于烟气脱硫.通过改变制备温度和尿素添加量等,研究了影响脱硫性能的主要含氮官能团.结果表明,含氮基团可以有效提高炭材料的脱硫性能.采用氮气吸附、元素分析和X射线光电子能谱等表征方法分析了炭材料的孔结构、含氮量和表面含氮基团的分布.结果表明,吡啶氮在炭材料脱硫过程中起主要作用,吡啶氮既可以促进SO2的吸附,又能促进SO2向SO3的催化氧化.