A Study on Alien Invasive Plants from the Interactive Mechanism between Species Niche and Material/Energy Flow

[Objective]This study was to reveal the essence of mechanism about how the alien invasive plants spread.[Method]Species niche and material/energy flow were used as basic research indicators to analyze the intrinsic mechanism of alien plants invasion.[Result]Most of the invasive plants have not been explicitly defined and their effective control methods not brought forward.[Conclusion]Overrun of alien invasive plants depends on whether the niche of a species could be continuously met at spatial level.Based on this we put forward corresponding control measures,proposed an assumption to establish a cylinder-network model and discussed the definition of alien invasive plants.

Nanostructured energy materials for electrochemical energy conversion and storage: A review

Nanostructured materials have received tremendous interest due to their unique mechanical/electrical properties and overall behavior contributed by the complex synergy of bulk and interfacial properties for efficient and effective energy conversion and storage. The booming development of nanotechnology affords emerging but effective tools in designing advanced energy material. We reviewed the significant progress and dominated nanostructured energy materials in electrochemical energy conversion and storage devices, including lithium ion batteries, lithium-sulfur batteries, lithium-oxygen batteries, lithium metal batteries, and supercapacitors. The use of nanostructured electrocatalyst for effective electrocatalysis in oxygen reduction and oxygen evolution reactions for fuel cells and metal-air batteries was also included. The challenges in the undesirable side reactions between electrolytes and electrode due to high electrode/electrolyte contact area, low volumetric energy density of electrode owing to low tap density, and uniform production of complex energy materials in working devices should be overcome to fully demonstrate the advanced energy nanostructures for electrochemical energy conversion and storage. The energy chemistry at the interfaces of nanostructured electrode/electrolyte is highly expected to guide the rational design and full demonstration of energy materials in a working device. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.

MXene-based materials for electrochemical energy storage

Rechargeable batteries and supercapacitors are widely investigated as the most important electrochemical energy storage devices nowadays due to the booming energy demand for electric vehicles and hand-held electronics. The large surface-area-to-volume ratio and internal surface areas endow two-dimensional（2D） materials with high mobility and high energy density; therefore, 2D materials are very promising candidates for Li ion batteries and supercapacitors with comprehensive investigations. In 2011, a new kind of 2D transition metal carbides, nitrides and carbonitrides, MXene, were successfully obtained from MAX phases. Since then about 20 different kinds of MXene have been prepared. Other precursors besides MAX phases and even other methods such as chemical vapor deposition（CVD） were also applied to prepare MXene, opening new doors for the preparation of new MXene. Their 2D nature and good electronic properties ensure the inherent advantages as electrode materials for electrochemical energy storage. In this review, we summarize the recent progress in the development of MXene with emphasis on the applications to electrochemical energy storage. Also, future perspective and challenges of MXene-based materials are briefly discussed regrading electrochemical energy storage.

In situ transmission electron microscopy and artificial intelligence enabled data analytics for energy materials

Energy materials are vital to energy conversion and storage devices that make renewable resources viable for electrification technologies. In situ transmission electron microscopy(TEM) is a powerful approach to characterize the dynamic evolution of material structure, morphology, and chemistry at the atomic scale in real time and in operando. In this review, recent advancements of in situ TEM techniques for studying energy materials, including catalysts, batteries, photovoltaics, and thermoelectrics, are systematically discussed and summarized. The topics include a broad range of material transformations that are in situ stimulated by heating, biasing, lighting, electron-beam illuminating, and cryocooling under vacuum, liquid, or gas environments within TEM, as well as the mechanistic understanding of the associated solid-solid, solid-liquid, and solid-gas reactions elucidated by in situ TEM examination and operando measurements. Special focus is also put on the emerging progress of artificial intelligence enabled microscopy data analytics, including machine learning enhanced tools for retrieving useful information from massive TEM imaging, diffraction, and spectroscopy datasets, highlighting its merits and potential for automated in situ TEM experimentation and analysis. Finally, the pressing challenges and future perspectives on in situ TEM study for energy-related materials are discussed.

Recent progress on discovery and properties prediction of energy materials:Simple machine learning meets complex quantum chemistry

In nature,the properties of matter are ultimately governed by the electronic structures.Quantum chemistry(QC)at electronic level matches well with a few simple physical assumptions in solving simple problems.To date,machine learning(ML)algorithm has been migrated to this field to simplify calculations and improve fidelity.This review introduces the basic information on universal electron structures of emerging energy materials and ML algorithms involved in the prediction of material properties.Then,the structure-property relationships based on ML algorithm and QC theory are reviewed.Especially,the summary of recently reported applications on classifying crystal structure,modeling electronic structure,optimizing experimental method,and predicting performance is provided.Last,an outlook on ML assisted QC calculation towards identifying emerging energy materials is also presented.

Vision for energy material design:A roadmap for integrated data-driven modeling

The application scope and future development directions of machine learning models(supervised learning, transfer learning, and unsupervised learning) that have driven energy material design are discussed.

Photon-in/photon-out endstation for studies of energy materials at beamline 02B02 of Shanghai Synchrotron Radiation Facility

A new photon-in/photon-out endstation at beamline 02B02 of the Shanghai Synchrotron Radiation Facility for studying the electronic structure of energy materials has been constructed and fully opened to users.The endstation has the capability to perform soft x-ray absorption spectroscopy in total electron yield and total fluorescence yield modes simultaneously.The photon energy ranges from 40 eV to 2000 eV covering the K-edge of most low Z-elements and the L-edge of 3d transition-metals.The new self-designed channeltron detector allows us to achieve good fluorescence signals at the low photon flux.In addition,we synchronously collect the signals of a standard reference sample and a gold mesh on the upstream to calibrate the photon energy and monitor the beam fluctuation,respectively.In order to cross the pressure gap,in situ gas and liquid cells for soft x-ray absorption spectroscopy are developed to study the samples under realistic working conditions.

Electrochemical characterization of MnO_2 as electrocatalytic energy material for fuel cell electrode

Development of inexpensive non Pt based high electrocatalytic energy materials is the need of the hour for fuel cell electrode to produce clean alternative green energy from synthesized bio alcohol using biomass. MnO 2,electro synthesized at different current density is found to be well performed electrocatalytic material,comparable to Pt,with higher current density,very lowovervoltage for the electrochemical oxidation of methanol. From EIS study,the polarization resistance of the coated MnO 2is found to be much lowand electrical double layer capacitance is high,the effect increases with increase in current density of electro deposition. XRD,EDX and AAS analysis confirm the M nO 2deposition. The morphology of SEM images exhibits an enhanced 3D effective substrate area,for electro oxidation of the fuel. A fewnano structured grains of the deposited M nO 2is also observed at higher current density. The fact supports that a high energetic inexpensive electro catalytic material has been found for fuel cell electrode to synthesis renewable energy from methanol fuel.

New carbon-nitrogen-oxygen compounds as high energy density materials

Molecular crystals are complex systems exhibiting various crystal structures,and accurately modeling the crystal structures is essential for understanding their physical behaviors under high pressure.Here,we perform an extensive structure search of ternary carbon-nitrogen-oxygen(CNO)compound under high pressure with the CALYPSO method and first principles calculations,and successfully identify three polymeric CNO compounds with Pbam,C2/m and I4m2symmetries under 100 GPa.More interestingly,these structures are also dynamically stable at ambient pressure,and are potential high energy density materials(HEDMs).The energy densities of Pbam,C2/m and I4m2 phases of CNO are about2.30 kJ/g,1.37 kJ/g and 2.70 kJ/g,respectively,with the decompositions of graphitic carbon and molecular carbon dioxide andα-N(molecular N_(2))at ambient pressure.The present results provide in-depth insights into the structural evolution and physical properties of CNO compounds under high pressures,which offer crucial insights for designs and syntheses of novel HEDMs.

Preface to Special Topic:Graphene and 2D Materials for Energy Storage

Graphene, a single layer of graphite, has been one of the first real two dimensional （2D） materials isolated in 2004. Thus, graphene is becoming a cutting edge material that opens up new horizons to a whole family of 2D materials beyond the limited current applicability of graphene. The unique advantages of graphene and analogue 2D materials, such as atomic-scale thickness, high specific surface area, mechanically flexible robustness, superior storage capacity, endow them as high-performance electrodes lbr electrochemical energy storage devices. Although it is hard to say whether or not graphene and 2D materials will be implemented in future energy technologies, the recent achievements in this field demonstrate that their roles will be noticeable in the near future.

Preface to Special Issue on Carbon Materials for Energy Application

The rising cost and limited availability of fossil fuels, and the increasing concerns related to their role on global pollution and greenhouse effect have pushed considerably the need to accelerate the transition to a more sustainable use of energy based largely on renewable energy sources. Nanocarbon materials play a critical role in this transition, as they are the key materials for components of different devices necessary in enabling this transition （batteries, fuel cells, solar cells, etc.）. This issue collects 22 contributions, including one perspective and six review papers on the topic of carbon materials for energy applications, written by well-known experts in this field. It is really an exciting special issue that gives a very updated view of this topic, as well as trends and outlooks in this breakthrough research area. The initial perspective paper introduces the different possibilities offered from the growing level of knowledge in this area, testified from the exponentially rising number of publications. It also discusses the basie concepts for a rational design of these nanomaterials. The lk）llowing six reviews address different specific aspects of synthesis, characterization and use of carbon nanomaterials, from fuel cells to composite electrodes, supercapacitors and photoelectrochemical devices for CO2 conversion. These reviews represent an unique opportunity for the readers to be updated on the latest developments of new carbon families such as fullerene, grapbene, and carbon nanotube, and their derived nanocarbon materials （from carbon quantum dots to nanohorn, nanofiber, nano ribbon, etc.）. Second generation nanocarbons, including modification of these nanocarbons by surface functionalization or doping with heteroatoms to create specific tailored properties, and nanoarchitectured supramolecular hybrids, are also discussed. Finally, 1 communication and 14 full articles discuss several aspects of the use of these nanocarbon materials to develop new catalysts for a range of applications （from biomass conversion to Fisher-Tropsch reaction and electrochemical devices） and new materials for energy storage and conversion （adsorption pumps, Li-ion and Li-S batteries, electrodes for electrochemical uses）. We thus believe that this special issue dedicated to the use and development of carbon materials for energy applications represents a unique occasion for young and experienced researchers as well as for managers in the field of sustainable energy to have an updated view on this enabling topic for the future of our society. We thus invite all to have this special issue as a privileged component of your bookshelf.

Uncover the Aesthetic Simplicity Associated with Mass Transfer in Energy Materials

Aesthetics,referred frequently to as a philosophical term,has played a starring role in forming and evolving a number of aspects of human society,including arts,politics,economics,ethics,etc.Indeed,exploring and investigating the aesthetic phenomena in the scientific field have aroused insightful research findings,which in turn has stimulated research interests in such a science-aesthetics field.In particular,better-evaluated aesthetic aspects of the materials field are expected to be uncovered upon the exceedingly-exposed fundamental breakthroughs in researching the basic structure and functionality of materials.In this report,we glimpse into the aesthetic simplicity of energy materials and comprehend specifically the mass transfer functionalities of key categories of energy materials through an intuitive and bottom-up approach.Our effort aspires to shed new lights on the functionality understanding and manipulation of functional materials in general.

Special Issue on New Concepts and Advances in Photocatalytic Materials for Sustainable Energy

The use of solar energy to drive the chemical and energy processes,and the chemical storage of solar energy are the key elements to move to a low-carbon economy,sustainable society and to foster energy transition.For this reason,there is a fast-growing scientific interest on this subject,which is part of the general effort for a solar-driven chemistry and energy,the chemistry of the future.To realize this

Material,energy and spatial fields for metallogenic prediction:Theory and practice An example:Limu Sn polymetallic crisis mines

The Limu tin deposits located in the Nanling tin and tungsten-polymetallic ore belt are now facing resource depletion after decades of exploitation.Peripheral mineral exploration therefore has become an urgent task.Using mineral exploration around the Limu crisis mines as an example,we introduce a breakthrough method of how the three-field theory,i.e.,the material,energy and spatial fields,is applied to intensively studies areas,a history of years of mineral exploitation and complex ore-forming systems.Taking a cue from Limu regional metallogeny,we based our investigation on the metallogenic information from geology,geophysics,geochemistry and remote sensing.We conducted our study of the three-field integrated information system,associated with metallogenic prognoses from deposits,with assignments and calculations which correct and allocate synthetic metallogenic prognosis by relying on GIS.We submitted a synthetic metallogenic prognosis map of tin in Limu where we delineated three ore target areas.A breakthrough was achieved by finding about 4785 t of tin metal outside the Shiziling deposit,which has been confirmed by drilling.The successful application in Limu shows that this three-field theory is of scientific and practical importance and deserves to be extended to utilization.

A Brief Analysis of Energy Conservation Ways by Building Materials for Ecological Architecture

The development of society and economy in China is bringing growth to all industries. In particular, the development of China’s building industry has attracted much attention. Building materials are an important part of and widely used in the building industry. Energy conservation by building materials has become an inevitable way of sustainable development. Centering on the building industry, this paper mainly discusses in detail the energy conservation ways by ecological architecture and building materials.

In Situ Mineralization of Biomass-Derived Hydrogels Boosts Capacitive Electrochemical Energy Storage in Free-Standing 3D Carbon Aerogels

Here,a novel fabrication method for making free-standing 3D hierarchical porous carbon aerogels from molecularly engineered biomass-derived hydrogels is presented.In situ formed flower-like CaCO_(3)molecularly embedded within the hydrogel network regulated the pore structure during in situ mineralization assisted one-step activation graphitization(iMAG),while the intrinsic structural integrity of the carbon aerogels was maintained.The homogenously distributed minerals simultaneously acted as a hard template,activating agent,and graphitization catalyst.The decomposition of the homogenously distributed CaCO_(3)during iMAG followed by the etching of residual CaO through a mild acid washing endowed a robust carbon aerogel with high porosity and excellent electrochemical performance.At 0.5 mA cm^(-2),the gravimetric capacitance increased from 0.01 F g^(-1)without mineralization to 322 F g^(-1)with iMAG,which exceeds values reported for any other free-standing or powder-based biomass-derived carbon electrodes.An outstanding cycling stability of~104%after 1000 cycles in 1 M HClO4 was demonstrated.The assembled symmetric supercapacitor device delivered a high specific capacitance of 376 F g^(-1)and a high energy density of 26 W h kg^(-1)at a power density of 4000 W kg^(-1),with excellent cycling performance(98.5%retention after 2000 cycles).In combination with the proposed 3D printed mold-assisted solution casting(3DMASC),iMAG allows for the generation of free-standing carbon aerogel architectures with arbitrary shapes.Furthermore,the novel method introduces flexibility in constructing free-standing carbon aerogels from any ionically cross-linkable biopolymer while maintaining the ability to tailor the design,dimensions,and pore size distribution for specific energy storage applications.

A seven-crystal spectrometer for high-energy resolution X-ray spectroscopy at Shanghai Synchrotron Radiation Facility

A Johann-type X-ray spectrometer was successfully developed at the hard X-ray branch(in-vacuum undulator with a 24-mm periodic length)of the energy material beamline(E-line)at the Shanghai Synchrotron Radiation Facility(SSRF).This spectrometer was utilized to implement X-ray emission spectroscopy(XES),high-energy resolution fluorescence-detected X-ray absorption spectroscopy(HERFD-XAS),and resonant inelastic X-ray scattering.Seven spherically bent crystals were positioned on the respective vertical 500-mm-diameter Rowland circles,adopting an area detector to increase the solid angle to 1.75%of 4πsr,facilitating the study of low-concentrate systems under complex reaction conditions.Operated under the atmosphere pressure,the spectrometer covers the energy region from 3.5 to 18 keV,with the Bragg angle ranging from 73°to 86°during vertical scanning.It offers a promised energy resolution of sub-eV(XES)and super-eV(HERFD-XAS).Generally,these comprehensive core-level spectroscopy methods based on hard X-rays at the E-line with an extremely high photon flux can meet the crucial requirements of a green energy strategy.Moreover,they provide substantial support for scientific advances in fundamental research.

Preparation of inorganic molten salt composite phase change materials and study on their electrothermal conversion properties

Due to their limitations in conductivity and shape stability,molten salt phase change materials have encountered obstacles to effectively integrating into electric heating conversion technologies,which are crucial in energy storage and conversion fields.In this study,we synthesized an inorganic molten salt composite phase change material(CPCM)with enhanced conductivity and shape stability using a gasphase silica adsorption method.Our findings revealed the regularities in thermal properties modulation by expanded graphite(EG)within CPCM and delved into its characteristics of electric heating conversion.The study elucidated that a conductive network is essentially formed when the EG content exceeds 3 wt%.Following the fabrication of CPCM into electric heating conversion modules,we observed a correlation between the uniformity of module temperature and the quantity of EG,as well as the distribution of electrode resistance and external voltage magnitude.Building upon this observation,we proposed a strategy to adjust the module temperature field with an electric field.Comparing the proposed direct electrical heating energy storage method with traditional indirect electrical heating methods,the energy storage rate increases by 93.8%,with an improved temperature uniformity.This research offers valuable insights for the application of molten salt electric heating conversion CPCMs.

Rechargeable metal(Li, Na, Mg, Al)-sulfur batteries: Materials and advances

Energy and environmental issues are becoming more and more severe and renewable energy storage technologies are vital to solve the problem.Rechargeable metal(Li,Na,Mg,Al)-sulfur batteries with low-cost and earth-abundant elemental sulfur as the cathode are attracting more and more interest for electrical energy storage in recent years.Lithium-sulfur(Li-S),room-temperature sodium-sulfur(RT Na-S),magnesium-sulfur(Mg-S)and aluminum-sulfur(Al-S)batteries are the most prominent candidates among them.Many obvious obstacles are hampering the developments of metal-sulfur batteries.Li-S and Na-S batteries are encumbered mainly by anode dendrite issues,polysulfides shuttle and low conductivity of cathodes.Mg-S and Al-S batteries are short of suitable electrolytes.In this review,relationships between various employed nanostructured materials and electrochemical performances of metal-sulfur batteries have been demonstrated.Moreover,the selections of suitable electrolytes,anode protection,separator modifications and prototype innovations are all crucial to the developments of metal-sulfur batteries and are discussed at the same time.Herein,we give a review on the advances of Li-S,RT Na-S,Mg-S and Al-S batteries from the point of view of materials,and then focus on perspectives of their future developments.

Simulation of facet dendrite growth with strong interfacial energy anisotropy by phase field method

Numerical simulations based on a new regularized phase-field model were presented, to simulate the solidification of hexagonal close-packed materials with strong interfacial energy anisotropies. Results show that the crystal grows into facet dendrites,displaying six-fold symmetry. The size of initial crystals has an effect on the branching-off of the principal branch tip along the<100> direction, which is eliminated by setting the b/a(a and b are the semi-major and semi-minor sizes in the initial elliptical crystals, respectively) value to be less than or equal to 1. With an increase in the undercooling value, the equilibrium morphology of the crystal changes from a star-like shape to facet dendrites without side branches. The steady-state tip velocity increases exponentially when the dimensionless undercooling is below the critical value. With a further increase in the undercooling value, the equilibrium morphology of the crystal grows into a developed side-branch structure, and the steady-state tip velocity of the facet dendrites increases linearly. The facet dendrite growth has controlled diffusion and kinetics.