Biomass-derived materials for electrochemical energy storages

During the past decade humans have witnessed dramatic expansion of fundamental research as well as the commercialization in the area of electrochemical energy storage, which is driven by the urgent demand by portable electronic devices, electric vehicles, transportation and storage of renewable energy for the power grid in the clean energy economy. Li-secondary batteries and electrochemical capacitors can efficiently convert stored chemical energy into electrical energy, and are currently the rapid-growing rechargeable devices. However, the characteristic (including energy density, cost, and safety issues, etc.) reported for these current rechargeable devices still cannot meet the requirements for electric vehicles and grid energy storage, which are mainly caused by the limited properties of the key materials (e.g. anode, cathode, electrolyte, separator, and binder) employed by these devices. Moreover, these key materials are normally far from renewable and sustainable. Therefore great challenges and opportunities remain to be realized are to search green and low-cost materials with high performances. A large number of the properties of biomass materials-such as renewable, low-cost, earth-abundant, specific structures, mechanical property and many others-are very attractive. These properties endow that biomass could replace some key materials in electrochemical energy storage systems. In this review, we focus on the fundamentals and applications of biomass-derived materials in electrochemical energy storage techniques. Specifically, we summarize the recent advances of the utilization of various biomasses as separators, binders and electrode materials. Finally, several perspectives related to the biomass-derived materials for electrochemical energy storages are proposed based on the reported progress and our own evaluation, aiming to provide some possible research directions in this field.     

Recent Advances in Porphyrin-Based Systems for Electrochemical Oxygen Evolution Reaction

Oxygen evolution reaction (OER) plays a pivotal role in the development of renewable energy methods, such as water-splitting devices and the use of Zn–air batteries. First-row transition metal complexes are promising catalyst candidates due to their excellent electrocatalytic performance, rich abundance, and cheap price. Metalloporphyrins are a class of representative high-efficiency complex catalysts owing to their structural and functional characteristics. However, OER based on porphyrin systems previously have been paid little attention in comparison to the well-described oxygen reduction reaction (ORR), hydrogen evolution reaction, and CO₂ reduction reaction. Recently, porphyrin-based systems, including both small molecules and porous polymers for electrochemical OER, are emerging. Accordingly, this review summarizes the recent advances of porphyrin-based systems for electrochemical OER. Firstly, the electrochemical OER for water oxidation is discussed, which shows various methodologies to achieve catalysis from homogeneous to heterogeneous processes. Subsequently, the porphyrin-based catalytic systems for bifunctional oxygen electrocatalysis including both OER and ORR are demonstrated. Finally, the future development of porphyrin-based catalytic systems for electrochemical OER is briefly prospected.     

Nanocellulose-based polymer composites for energy applications—A review

With rapid fossil fuel consumption and ecological concerns, alternative options of green energy development and its efficient storage technology is an emergent area of research. Nanocellulose is observed to be a very-promising sustainable and environmentally friendly nanomaterial for green and renewable electronics for advanced electrochemical energy conversion/conservation devices. This review begins with a basic introduction on the sources and properties of nanocellulose. It provides an overview of the recent advancements made by researchers in integrating nanocellulose with active materials to form a flexible film/aerogel/3D structures as a substrate for powering portable electronics, electric vehicles, etc. The review highlights the use of nanocellulose-based composites in energy conversion devices such as solar cells, piezoelectric materials, and lithium ion batteries. Recent research shows that the power conversion efficiency of solar cells and the piezoelectric performance of piezoelectric materials can be increased when the matrix is reinforced with nanocellulose. The review also focuses on the updates of nanocellulose-based composites in separators, binders, and electrodes of energy conservation devices such as supercapacitors, and energy capture devices such as CO₂ separators. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48959.     

Recent advances in microbial fuel cells (MFCs) and microbial electrolysis cells (MECs) for wastewater treatment,bioenergy and bioproducts

Bioenergy is a renewable energy that plays an indispensable role in meeting today's ever increasing energy needs. Unlike biofuels, microbial fuel cells (MFCs) convert energy harvested from redox reactions directly into bioelectricity. MFCs can utilize low‐grade organic carbons (fuels) in waste streams. The oxidation of the fuel molecules requires biofilm catalysis. In recent years, MFCs have also been used in the electrolysis mode to produce bioproducts in laboratory tests. MFCs research has intensified in the past decade and the maximum MFCs power density output has been increased greatly and many types of waste streams have been tested. However, new breakthroughs are needed for MFCs to be practical in wastewater treatment and power generation beyond powering small sensor devices. To reduce capital and operational costs, simple and robust membrane‐less MFCs reactors are desired, but these reactors require highly efficient biofilms. Newly discovered conductive cell aggregates, improved electron transport through hyperpilation via mutation or genetic recombination and other advances in biofilm engineering present opportunities. This review is an update on the recent advances on MFCs designs and operations. © 2012 Society of Chemical Industry     

CHEMICAL ENGINEERING FOR TECHNOLOGY INNOVATION

Sustainability of human beings in the 21st century requires development of renewable energy systems based on technology innovation. Chemical engineering plays a key role in promoting technology innovation relating to environmental and energy systems. The technological domains to which chemical engineering has contributed have shift from petrochemicals to functional materials and devices. An example of the key devices expected in the future is a combination of solar cells and Li-ion batteries, in which the indispensable materials are silicon and carbon. The shape and nanostructure of materials must be controlled to fabricate highly efficient devices at a low cost. Single-walled carbon nanotubes (SWNT) and spherical silicon solar cells (SSSC) with a semi-concentration reflector system are discussed as examples of future materials and devices. Chemical engineering is responsible for technology innovation through mass production, product quality control, materials recycling, high-quality device fabrication, and structuring knowledge.     

新能源化工技术

发展新能源是实现“碳中和”战略目标的必由之路。本文首先勾画出可再生能源转换利用基本途径,指出新能源化工技术研究的理论基础是电化学工程、光化学工程、生物化学工程、分子化学工程、系统工程和人工智能等;其次,以可再生能源制氢、燃料电池发电与化学品共生、太阳能转换过程为例,阐明可再生能源资源转换中的化工问题;第三,通过对锂离子电池和钠离子电池中多元过渡金属氧化物正极材料及其电极制备过程开发,揭示电化学储能材料与器件制造过程工程特性;第四,介绍了化工系统工程和人工智能在电池状态预测模型构建、综合能源系统管理、光-储-充系统集成与优化运行中的应用。最后,根据各种案例分析,归纳出新能源化工研究的本质是将新能源转换与储存中涉及的“生物/光/电化学反应”,从实验室放大到规模化生产装置,阐明反应中的传质、传热和传荷机理及其反应工程特性。对未来新能源化工技术研发,从“共性科学问题”和“关键技术”两个层面提出了若干研究方向以供参考。     

Process engineering in electrochemical energy devices innovation

This review focuses on the application of process engineering in electrochemical energy conversion and storage devices innovation. For polymer electrolyte based devices, it highlights that a strategic simple switch fromproton exchange membranes (PEMs) to hydroxide exchange membranes (HEMs) may lead to a new-generation of affordable electrochemical energy devices including fuel cells, electrolyzers, and solar hydrogen generators. For lithium-ion batteries, a series of advancements in design and chemistry are required for electric vehicle and energy storage applications. Manufacturing process development and optimization of the LiFePO₄/C cathodematerials and several emerging novel anode materials are also discussed using the authors' work as examples. Design and manufacturing process of lithium-ion battery electrodes are introduced in detail, and modeling and optimization of large-scale lithium-ion batteries are also presented. Electrochemical energy materials and device innovations can be further prompted by better understanding of the fundamental transport phenomena involved in unit operations.     

改善锂硫电池易燃特性的功能性隔膜研究进展

锂硫电池具有较高的能量密度,可在单兵电源、无人机和乘用车领域应用. 锂硫电池以金属锂作为负极,使用时存在安全隐患. 由于锂金属表面的不均匀性,循环过程容易生成锂枝晶,使电池内部发生短路,起火燃烧. 锂硫电池的能量密度约为普通电池的3~5倍,在充放电过程中发热严重,电池本身过热容易引发电池热失控,造成起火甚至爆炸. 使用功能性隔膜可以抑制电池内部短路和热失控的发生,提升锂硫电池的安全性能,可一定程度上削弱循环过程中的飞梭效应. 本文综述了锂硫电池功能性隔膜改性工作的最新进展和未来的发展趋势.     

Enzyme immobilization onto renewable polymeric matrixes: Past,present, and future trends

In this review, we present an overview of the different renewable polymers that are currently being used as matrixes for enzyme immobilization and their properties and of new developments in biocatalysts preparation and applications. Polymers obtained from renewable resources have attracted much attention in recent years because they are environmentally friendly and available in large quantities from natural sources. Different methods for the immobilization of enzymes with these matrixes are reviewed, in particular: (1) binding to a prefabricated biopolymer, (2) entrapment, and (3) crosslinking of enzyme molecules. Emphasis is given to relatively recent developments, such as the use of novel supports, novel entrapment methods and protocols of polymer derivatization, and the crosslinking of enzymes. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42125.     

Seawater desalination driven by renewable energies: a review

This paper deals with seawater desalination systems driven by renewable energies. A review of pilot plants and perspectives of development is presented. There are many reasons why the use of renewable energies in seawater desalination is suitable, especially for remote areas where conventional energy supply and skilled workers are not usually available. Nevertheless, desalination systems driven by renewable energies are scarce and they tend to have a limited capacity.     

A review of high energy density lithium–air battery technology

Today’s lithium (Li)-ion batteries have been widely adopted as the power of choice for small electronic devices through to large power systems such as hybrid electric vehicles (HEVs) or electric vehicles (EVs). However, it falls short of meeting the demands of new markets in these areas of EVs or HEVs due to insufficient energy density. Therefore, new battery systems such as Li–air batteries with high theoretical specific energy are being intensively investigated, as this technology could potentially make long-range EVs widely affordable. So far, Li–air battery technology is still in its infancy and will require significant research efforts. This review provides a comprehensive overview of the fundamentals of Li–air batteries, with an emphasis on the recent progress of various elements, such as lithium metal anode, cathode, electrolytes, and catalysts. Firstly, it covers the various types of air cathode used, such as the air cathode based on carbon, the carbon nanotube-based cathode, and the graphene-based cathode. Secondly, different types of catalysts such as metal oxide- and composite-based catalysts, carbon- and graphene-based catalysts, and precious metal alloy-based catalysts are elaborated. The challenges and recent developments on electrolytes and lithium metal anode are then summarized. Finally, a summary of future research directions in the field of lithium air batteries is provided.     

多孔离子传导电池隔膜研究进展

具有高离子选择性和高电导率的离子传导膜对于以新能源为主体的新型电力系统（如液流电池、燃料电池、锂电池等）至关重要。近年来，研究者们提出了构建多孔离子传导膜以应对传统隔膜普遍存在的离子选择性和电导率之间的权衡效应。本综述从无机多孔离子传导膜、有机多孔离子传导膜以及多孔离子传导复合膜三个方面简要概述了近年来多孔离子传导膜作为电池隔膜的最新研究进展，总结了多孔离子传导膜在液流电池、燃料电池、锂电池等新能源电池中的前沿性工作，并指出未来多孔离子传导电池隔膜的研究将重点关注多孔膜结构的调控、高性能多孔膜材料的开发以及多孔膜在新型电池中的应用。     

Radiation-grafted materials for energy conversion and energy storage applications

Polymer electrolyte membranes are key components in electrochemical power sources that are receiving ever-growing demand for the development of more efficient, reliable and environmentally friendly energy systems. Ongoing research is focusing on materials with high ionic conductivity and stability, at low cost. Among different methods, radiation-induced grafting is a universal attractive method for preparation of polymer electrolyte materials with tunable properties for various energy conversion and energy storage applications. This review addresses recent advances in the application of radiation-induced grafting techniques for the preparation of polymer electrolyte membranes/separators for emerging electrochemical devices such as fuel cells, batteries and supercapacitors. The challenges associated with the current state-of-the-art materials are highlighted, together with new directions that should be considered for future research.     

锂硫电池功能化粘合剂研究进展

随着可持续能源的发展和电子设备及电动汽车对储能设备性能要求的不断提高，高能量密度的锂硫电池体系受到了广泛关注。当前锂硫电池仍然面临单质硫和其放电产物的电子绝缘性、多硫化物的“穿梭效应”和循环过程中体积形貌的变化等科学与技术问题，阻碍其实际应用。针对锂硫电池的上述瓶颈，设计多功能粘合剂有望提升活性材料的利用效率及循环寿命。本文在近年来研究的基础上综述了锂硫电池中粘合剂的研究进展，具有包括面向抑制副反应的粘合剂、面向稳定电极片的多维度粘结的粘合剂和面向低界面电阻的粘合剂，并展望了锂硫电池多功能粘合剂面临的科学挑战和未来发展的机遇。     

Horizons for Modern Electrochemistry Related to Energy Storage and Conversion,a Review

The purpose of this paper is to suggest frontier inter‐disciplinary research directions that can be considered as important horizons of modern electrochemistry in the field of energy storage and conversion. We selected several topics that call for advancements in solid‐state, interfacial, analytical and energy‐related electrochemical science. A dramatic improvement in the performance of energy storage and conversion devices is needed to meet the urgent demands of our society. Significantly more efficient devices are needed to meet two major challenges: electro‐mobility, namely electrochemical propulsion of electric vehicles, and the ability to store and convert large quantities of energy generated from sustainable sources such as sun and wind. We suggest promotion of breakthroughs in several important directions. The examples chosen include: Development of novel in‐situ methodologies for design and testing composite electrodes for advanced energy storage devices; Improving the electrochemical performance of high specific capacity, but hard to control, LiNiO₂ cathodes for advanced lithium ion batteries designed for electric vehicles, with a quantitative goal of stable specific capacity >230 mAh/g with a charging potential lower than 4.3 V; Advancing aqueous electrochemical systems for large energy storage based on sodium electrochemistry; Promoting development of batteries based on multivalent active metals with magnesium as the most advanced example. There is a strong incentive to promote fundamental and practical progress in the field of rechargeable Mg batteries using new electrodes’ configurations and advanced electroanalytical methods. All these directions require deep efforts in basic, fundamental studies, in order to reach important practical goals.     

An energy systems engineering approach for the design and operation of microgrids in residential applications

A distributed energy system refers to an energy system where energy production is close to end use, typically relying on small-scale energy distributed technologies. It is a multi-input and multi-output energy system with substantial energy, economic and environmental benefits. However, distributed energy systems such as micro-grids in residential applications may not be able to produce the potential benefits due to lack of appropriate system configurations and suitable operation strategies. The optimal design, scheduling and control of such a complex system are of great importance towards their successful practical realization in real application studies. This paper presents a short review and an energy systems engineering approach to the modeling and optimization of micro-grids for residential applications, offering a clear vision of the latest research advances in this field. Challenges and prospects of the modeling and optimization of such distributed energy systems are also highlighted in this work.     

低温等离子体在电化学储能器件表面修饰的应用

面对日益严峻的能源危机和环境污染，人类社会需减少化石燃料使用，发展新能源。以锂离子电池为代表的二次电池作为新能源存储设备在生活中得到了广泛应用。然而，在充放电过程中，以电极材料为代表的电化学储能器件面临体积膨胀、活性物质溶解等问题，影响二次电池的电容量和安全性。对电化学储能器件进行合理的表面修饰是改善上述问题的关键。等离子体具有高活性，可以有效抑制电极材料表面活性物质溶解、避免副反应的发生，提高二次电池的循环寿命和放电容量。本工作对等离子体技术，特别是低温等离子体进行了介绍，并总结了低温等离子体技术在电化学储能器件表面修饰中的最新进展，重点介绍了其在先进电极材料表面的应用，最后讨论了等离子体方法优点，并对其未来面临的挑战和应用进行了展望。     

钠离子电池负极材料的储钠机制及性能研究进展

绿色能源的应用,促使着电化学储能与转换技术的飞速发展。锂离子电池作为储能领域最成功的二次离子电池之一,已被应用于各种电子产品中,但是由于锂资源短缺造成锂离子电池的成本增加,限制了其在大规模储能设备领域的应用。因此,寻找价格低廉、性能优异的二次离子电池是当下的研究热门之一。钠离子电池不仅拥有和锂离子电池相似的工作原理,而且还具有成本低、资源丰度大和可逆容量高的特点,有望成功地代替锂离子电池而应用于商业化生产。本工作主要综述了钠离子电池负极材料的性能研究进展,首先根据钠离子在负极材料存储方式不同,分析归纳了负极材料的插层反应、合金化反应和转换反应三种储钠机制,然后介绍了负极材料的结构修改、元素掺杂和材料复合三种改性方式,随后重点介绍了碳基材料、钛基材料、合金类材料、转换类材料和有机材料等几种关键的钠离子电池负极材料的电化学性能和所面临的问题,最后,以实际生产和工业应用为基础,展望了钠离子电池负极材料的研究方向。     

氧电极金属单原子催化剂的研究进展

燃料电池和金属-空气电池作为目前最具发展前景的能量转换和储存设备,对于缓解人类发展所面临的能源与环境问题大有裨益。然而,较差的氧电极反应,如燃料电池中的氧还原反应以及锌空电池中的氧还原及析氧反应,却限制着这两类装置的高效运行。近年来,人们提出了利用单原子催化剂(SACs)来提高氧电极反应的反应动力学。因此,针对两类氧电极反应,本综述根据构成活性位点的不同金属元素进行了分类总结,重点关注了各类催化剂的共性及进展。同时,还对具有双功能的催化剂及其在锌空电池的应用进行了总结。最后,针对SACs目前存在的问题和未来的发展方向提出了建议,旨在为单原子氧电极催化剂的设计及发展指明道路。     

Advances in single-atom catalysts for oxygen electrodes

As the most promising energy conversion and storage devices, fuel cells and metal-air batteries are of great benefit in alleviating the energy and environmental problems. However, the sluggish oxygen electrode reactions, including oxygen reduction reaction (ORR) for fuel cell and ORR couple with oxygen evolution reaction (OER) for zinc-air batteries, seriously limit the efficient of both types of devices. In recent years, single-atoms catalysts (SACs) have been proposed to improve the kinetics of oxygen electrode reaction. Therefore, for these two types of oxygen electrode reactions, this review firstly summarized their possible mechanism. Then, the SACs were classified by the different metal elements for both ORR and OER. Thus, noble-metal-based and non-noble-metal-based catalysts have been summarized in these two reactions. At the same time, a summary of the dual-function catalyst and its application in zinc air batteries is also given. Finally, in view of the current problems and future development directions of SACs, suggestions are put forward, aiming to pave the way for the design and development of monoatomic oxygen electrode catalysts.