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[Display omitted] Lithium metal is deemed a promising anode material for the next-generation batteries with high specific energy. Unfortunately, the growth of Li dendrites and infinite volume change during cycling, caused by the "hostless" feature of metallic Li, have posed a great challenge to the commercialization of Li metal anode. The introduction of appropriate host materials for Li metal is highly desirable. In this work, a N, P dual-doped 3D carbon derived from low-cost quantitative filter paper (NPCQP) is designed and fabricated for direct using as a host for Li metal anode. The resulting NPCQP host achieves a high deposition/stripping Coulombic efficiency of above 97.5 % with a low nucleation overpotential. Moreover, the NPCQP@Li symmetric cells enable an excellent long-term cycling performance (1000 h) with an ultralow voltage hysteresis (12 mV) and stable interface behavior. When paired with the commercial LiFePO 4 cathode, the full cell with NPCQP@Li anode displays impressive long-term cyclic stability and rate capability, outperforming the counter cell with bare Li anode. This contribution sheds light on the rational design of viable host for practical lithium metal anodes. [ABSTRACT FROM AUTHOR]

The diffusion layer (DL) in the structure of the membrane electrode assembly (MEA) of a micro direct methanol fuel cell (μDMFC) plays an essential role in reactant/product mass transfer and catalyst loading. The material selection and structure design of the μDMFC affects its performance. In this work, a reduced graphene oxide/carbon paper (rGO/CP) was proposed and prepared for the anode DL of a μDMFC. It was prepared using electrophoretic sedimentation combined with an in situ reduction method. The rGO/CP reduced the cell's ohmic and charge transfer resistances. Meanwhile, it provided more significant mass transfer resistance to reduce the methanol crossover, allowing the cell to operate stably at higher concentrations for a longer duration than conventional μDMFCs. The experimental results showed that the maximum power density increased by 53% compared with the traditional anode DL of carbon paper. [ABSTRACT FROM AUTHOR]

Carbonaceous materials, especially with graphite‐layers structure, as anode for potassium‐ion batteries (PIBs), are the footstone for industrialization of PIBs. However, carbonaceous materials with graphite‐layers structure usually suffer from poor cycle life and inferior stability, not to mention freestanding and flexible PIBs. Here, a freestanding and flexible 3D hybrid architecture by introducing carbon dots on the reduced graphene oxide surface (CDs@rGO) is synthesized as high performance PIBs anode. The CDs@rGO paper has efficient electron and ion transfer channels due to its unique structure, thus enhancing reaction kinetics. In addition, the CDs provide abundant defects and oxygen‐containing functional groups, which can improve the electrochemical performance. This freestanding and flexible anode exhibits the high capacity of 310 mAh g−1 at 100 mA g−1, ultra‐long cycle life (840 cycles with a capacity of 244 mAh g−1 at 200 mA g−1), and excellent rate performance (undergo six consecutive currents changing from 100 to 500 mA g−1, high capacity 185 mAh g−1 at 500 mA g−1), outperforming many existing carbonaceous PIB anodes. The results may provide a starting point for high‐performance freestanding and flexible PIBs and promote the rapid development of next‐generation flexible batteries. [ABSTRACT FROM AUTHOR]

Microbial fuel cell is a promising technology to harvest energy from wastewater, and effective anode catalysts are essential for its applications. In this study, zero-dimension nitrogen-doped carbon dots, as biocompatible efficient modifiers, were synthesized and decorated onto the carbon paper surface to prepare microbial fuel cell anode. The as-fabricated nitrogen-doped carbon dots decorated carbon paper anode was able to enhance electricity generation and efficient wastewater treatment. It was found that the as-fabricated electrode had a high hydrophilicity, which was favorable for the microbial immobilization. Compared with the carbon paper anode, the biofilm on the as-prepared anode was almost twice of thickness. After introducing nitrogen-doped carbon dots, the extracellular electron transfer process from the microorganisms to the anode was enhanced. The microbial fuel cell with the as-developed anode generated a remarkable power output of 0.32 mW, 1.1 times higher than that of the raw carbon paper anode with same measurement area. Moreover, 16 sRNA pyrosequencing analysis shows that the quantity of Pseudomonas on the electrode increased by ∼40%, which also promoted the electron transfer rate by excreting mediators like phenazines or phenazine derivatives. This work developed a new approach to design microbial fuel cell anode material and fabricate a high-efficiency and environmentally friendly anode for electricity generation from wastewater. Image 100697 • Notable power output was obtained from MFC with N-doped CDs@carbon paper electrode. • The carbon paper electrode was highly hydrophilic by decorating with N-doped CDs. • The EET efficiency was enhanced by modifying the electrode with N-doped CDs. • The relative abundance of Pseudomonas was enhanced with N-doped CDs' decoration. [ABSTRACT FROM AUTHOR]

We synthesized a flexible lithium-ion battery (LIB) anode with a flower-like CuCo2O4 nanostructure grown on the surface of conductively-treated filter paper. The filter paper, made of cotton fibers, has good flexibility, but its poor conductivity limits its application in flexible electrodes. An Ni coating by magnetron sputtering can significantly improve its conductivity, which enables it to be used as a substrate for flexible electrodes. The flower-like CuCo2O4 nanostructure is assembled from CuCo2O4 nanowires with a diameter of 50 nm, while the CuCo2O4 nanowires are assembled from CuCo2O4 nanoparticles with a size of 10–20 nm. The gap between the stacked CuCo2O4 nanoparticles causes the porous structure of the CuCo2O4 nanowires. The high theoretical capacity of CuCo2O4, the porous structure of the CuCo2O4 nanowires, and the tiny CuCo2O4 nanoparticles lead to the excellent electrochemical performance of the CuCo2O4 flower-like nanostructure. It maintains capacity very well during cycling and delivers a high capacity of 989 mAh g−1 at a current density of 100 mA g−1. As a flexible LIB anode, the composite with the flower-like CuCo2O4 nanostructure grown on the surface of conductively-treated filter paper delivers a stable capacity of 544 mAh g−1 at a current density of 100 mA g−1 and a capacity of 304 mAh g−1 at a high current density of 2000 mA g−1. The conductively-treated filter paper substrate can significantly improve the battery property of the hydrothermally-fabricated CuCo2O4. [ABSTRACT FROM AUTHOR]

The space charge effect of transformer insulating paper will distort its internal electric field, and its space charge effect will be more prominent under extremely complex working conditions. At present, the micromechanism of charge transport and electric field distortion characteristics of paperboard are not clear under complex working conditions. So in this article, based on the bipolar carrier transport (BCT) model and the dynamic carrier balance model, the effects of high temperature, aging degree, moisture content, and bent degree on charges accumulation in paperboard are studied under dc high voltage by numerical simulation and the measured data needed for simulation. The results show that the higher temperature strengthens the carrier migration, deepens the injection depth of the charge, and aggravates the distortion of electric field intensity in paperboard. The more extended the aging time of paperboard, the greater the internal trap density and the deeper the trap depth, which lead to charges migration difficultly. Increasing water content in the paperboard will accelerate space charges to reach a steady state, while further increasing it will slow down this process, which is related to the shallow trap getting deeper. When the critical part of paperboard is extruded, many traps are introduced, resulting in charges accumulation seriously. The research results can reference the design of paperboard and the maintenance of transformer insulation system. [ABSTRACT FROM AUTHOR]

It is known that 1,2,3 benzotriazole (BTA) can effectively limit the oil flow electrification in oil–paper insulation used in HVAC transformers, but it is still unclear whether BTA is applicable to converter transformers. Thus, the effects of BTA on interface charge behaviors and charge migration in oil–paper system under dc stress are investigated in this article. The experimental results show that BTA reduces the interface barrier between oil and oil-immersed paper by altering the charge distribution of the electric double layer (EDL) at the oil–paper interface, which is beneficial to the operation stability of converter transformers in the condition of polarity inversion. However, it is also found that the BTA additive promotes the charge accumulation at oil–paper interface and enhances the local electric field by increasing the carrier mobility of oil–paper insulation. The experimental results in this article provide references for the selection of insulating oil additives for converter transformers. [ABSTRACT FROM AUTHOR]

MoO 3 -based anodes for lithium storage have attracted more attentions due to the relatively high specific capacity of 1117 mAh g–1 and good chemical stability. Compound MoO 3 with other functional materials and construction of unique micromorphologies have been proved to be efficient strategies for improving the electrochemical performances of MoO 3 -based anodes. Herein, MoO 3 /TiO 2 composites were successfully biosynthesized with different micromorphologies. In the preparation processes, the hydrothermal and solvothermal treatments were carried out successively in the presence of cellulosic filter paper as the biotemplate, followed by calcination of the as-obtained composites in air, resulting in the final MoO 3 /TiO 2 composite materials. The two microstructures of the MoO 3 microfiber with entire TiO 2 nanoparticles coating and the MoO 3 microrod formed by stacking the microsheets with loosely TiO 2 nanoparticles covering were prepared under different pH values of the precursor. Compared with the bare MoO 3 materials, the corresponding MoO 3 /TiO 2 composites showed enhanced electrochemical performances as anode materials for lithium-ion batteries. Especially the MoO 3 /TiO 2 composite with core-shell microfibrous structure derived from cellulosic filter paper presented relatively better test results for lithium storage, delivering an initial discharge capacity of 1297.6 mAh g−1 with the first Coulombic efficiency of 65.8%, and a reversible specific capacity of 403.6 mAh g−1 after 200 cycles. It is demonstrated that a well-defined TiO 2 coating layer can effectively inhibit the volume variations of MoO 3 matter in the lithiation/delithiation processes. Combined with the porous microfibrous structure that alleviates the stress, provides more reaction sites and reduces diffusion paths of lithium-ion, a promising MoO 3 -based anode material was achieved. This work provides a facile biotemplate-based strategy for the design and fabrication of metal oxide-based composites with adjustable microstructures for energy storage. [Display omitted] • Cellulosic filter paper derived MoO 3 /TiO 2 composites with variable micromorphologies were biosynthesized. • Microfibrous MoO 3 was coated by TiO 2 nanoparticles uniformly using the precursor with original pH value. • It showed enhanced reversible capacity, cycling stability and rate capability as an anode material for lithium-ion batteries. • The microstructural feature of biotemplate and the entire TiO 2 coating contribute to the improved lithium storage property. [ABSTRACT FROM AUTHOR]

Abstract: We have developed a new Si-based anode for lithium secondary batteries consisting of a carbon paper substrate and Si/C composite deposited on it (Si/C/CP electrode). The Si/C composite was formed by pyrolysis of a slurry consisting of Si power and THF solution of PVC as the carbon precursor. The electrode contains no additional conductive carbon and binder, which supports the tight contact among the Si particle, pyrolytic carbon and carbon paper. The Si/C/CP electrode with the three-dimensional carbon fiber framework of the carbon paper was also advantageous to absorb severe volume changes of silicon particles. The electrode performance revealed that the Si/C/CP electrode prepared from the mixture of Si and PVC with the ratio of 10:90 by weight had a quite high initial capacity of 1720 mAh g−1 and initial Coulombic efficiency of 90%, and also exhibited excellent capacity retention with a reversible capacity of 1200 mAh g−1 even after 100 cycles. [Copyright &y& Elsevier]

Abstract: Tin on a carbon paper (CP) was investigated by repeated galvanostatic cycles with time-limited charges to insert different amounts of lithium per Sn atom, and tin electrodeposited on copper was also investigated for comparison of the cyclic stability. The results demonstrated that, unlike Sn electrodeposited on Cu foil, Sn on CP can undergo several tens of lithiathion/delithiation cycles with Li/Sn atomic ratio ≤2 at high current density (0.70mAcm-2), thus confirming that carbon paper is a good current collector-substrate which is able to improve the cycling performance of tin by preserving the electric contact over cycling, in spite of the great volume changes during the lithium insertion/removal processes in tin. [Copyright &y& Elsevier]

Abstract α-Fe 2 O 3 nanoparticles/multi-wall carbon nanotubes (MWCNTs) hybrids were successfully prepared via a facile one-step hydrothermal method. The MWCNTs enhances the conductivity and provides space for stress and strain during volume expansion of α-Fe 2 O 3 semiconductor as the anode for LIBs. The composite shows impressive electrochemical performance when it was used as the electrodes of coin cells. The α-Fe 2 O 3 electrode with 50 wt% MWCNTs retains its capacity of 816.8 mAh g−1 after 50 cycles at the current density of 200 mA g−1, which is superior to those of contrast samples (bare α-Fe 2 O 3 , pure MWCNTs, 10 wt%, 30 wt%, 70 wt% MWCNT/α-Fe 2 O 3 hybrids). Furthermore, the flexible carbon nanofiber paper (CNP) has also been investigated as a novel current collector with lithium storage for application in LIBs, and the capacity of free-standing α-Fe 2 O 3 /50 wt%MWCNTs/CNP hybrids electrode can retain 467.2 mAh g−1 after 50 cycles under the current density of changes from 2500 mA g−1 to 200 mA g−1. The MWCNTs improved cycle performance, enhanced reversible capacities and rate capability of MWCNTs/α-Fe 2 O 3 anodes can attribute to the inherent conducting network, shorten electron pathway and faster reaction kinetics. Highlights • α-Fe 2 O 3 /MWNT nanocomposite electrodes for flexible LIBs. • α-Fe 2 O 3 embedded in the outer carbon nanotube. • Hybrids electrode exhibits superior electrochemical properties. • Free-standing carbon nanofiber paper applied to light-weighted LIBs. [ABSTRACT FROM AUTHOR]

A filter-paper-derived nanofibrous silica–carbon composite composed of thin silica layer conformally coated on carbon nanofibers is synthesized by employing natural cellulose substance (ordinary laboratory filter paper) as both scaffold and carbon source. When the nanocomposite is employed as an anode material for lithium-ion batteries, it displays improved lithium-ion storage performance compared with the bare silica and carbon counter materials, due to the unique three-dimensional porous network structures of the carbon fiber scaffold and the thin silica layer. For the silica–carbon nanocomposite with 31.2 wt% of silica content and the silica layer with a thickness of ca. 60 nm, it delivers a stable discharge capacity of ca. 400 mAh g −1 after 200 discharge/charge cycles at a current density of 100 mA g −1 . Moreover, improved electrochemical performances are achieved by coverage of an additional carbon layer or deposition of silver nanoparticles onto the silica–carbon nanofibers, which exhibits specific capacities of 488.7 and 477.5 mAh g −1 after 100 discharge/charge cycles, respectively. The current synthetic method provides a facile and low-cost strategy for the large-scale production of nanofibrous silica–carbon based composites as anodic materials for lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Li metal anode with high capacity, negative potential and low density is regarded as the most promising anode material. Unfortunately, its commercialization is greatly limited by Li dendrites. Here, a 3D carbon paper scaffold with lithiophilic carbon nanoparticles is synthesized as a Li host via the carbonization of metal-organic framework and the doping of oxygen atom. Carbon nanoparticles effectively improve the specific surface area of carbon paper that can low the local current density and provide rich internal spaces for Li reservoir. In addition, the rich lithiophilic groups (such as ZnO, nitrogen atom and oxygen atom) can regulate a uniform Li+ flux and achieve a controllable Li deposition. Based on these structural advantages, uniform nucleation and growth of Li metal have been realized. Especially, the symmetric cell renders an outstanding cyclic stability for 750 h with an ultra-low polarization voltage of 14 mV at 1 mA/cm2. Additionally, the full cell partied with a LiFePO 4 cathode displays an initial specific capacity of 138.1 mAh/g, and even maintains 97.7 % capacity retention after 120 cycles at 0.5C. Therefore, this strategy presents a universal approach to construct porous hosts with abundant lithiophilic sites for long-lifespan Li metal batteries. [Display omitted] • We propose a strategy to construct porous hosts with abundant lithiophilic sites. • Zn–O@CP host can regulate uniform Li ionic flux and dendrite-free Li deposition. • Zn–O@CP host displays a low polarization voltage of 14 mV for 750 h. • Zn–O@CP host can be applied to both in anode-free cells and in Li metal cells. [ABSTRACT FROM AUTHOR]

Freestanding tin oxide-boron oxide/reduced graphene oxide (SnO2-B2O3/rGO) nanocomposite anode was produced for Li-ion cells. This binder-free flexible paper anode structure was fabricated by combining SnO2-B2O3 composite and graphene oxide which were synthesized through the sol–gel method and Hummers’ method, respectively. Field emission gun scanning electron microscopy, high-resolution transmission electron microscopy, energy dispersive X-ray spectrometer, Fourier transform infrared spectroscopy, Raman spectroscopy, and X-ray diffraction were utilized to characterize anode materials. The Williamson-Hall (W-H) analysis was applied using XRD data to determine crystal size and strain of the lattice. Electrochemical tests, cyclic voltammetry, and electrochemical impedance spectroscopy measurements were performed to determine electrochemical properties of the anodes. The results indicated that the anode formed with SnO2-B2O3 particles anchored on the rGO layers provided higher discharge capacity (838 mAhg-1) than that of SnO2/rGO (395 mAh g-1) after 100 cycles. The electron-deficient nature of boron supplied an effective increase in electrochemical energy storage performance. [ABSTRACT FROM AUTHOR]

Hard carbon is regarded as the most promising anode material for sodium-ion (Na-ion) batteries, owing to its advantages of high abundance, low cost, and low operating potential. However, the rate capability and cycle life span of hard carbon anodes are far from satisfactory, severely hindering its industrial applications. Here, we demonstrate that the desolvation process defines the Na-ion diffusion kinetics and the formation of a solid electrolyte interface (SEI). The 3A zeolite molecular sieve film on the hard carbon is proposed to develop a step-by-step desolvation pathway that effectively reduces the high activation energy of the direct desolvation process. Moreover, step-by-step desolvation yields a thin and inorganic-dominated SEI with a lower activation energy for Na+ transport. As a result, it contributes to greatly improved power density and cycling stability for both ester and ether electrolytes. When the above insights are applied, the hard carbon anode achieves the longest life span and minimum capacity fading rate at all evaluated current densities. Moreover, with the increase in current densities, an improved plateau capacity ratio is observed. This step-by-step desolvation strategy comprehensively enhances various properties of hard carbon anodes, which provides the possibility of building practical Na-ion batteries with high power density, high energy density, and durability. [ABSTRACT FROM AUTHOR]

Co-doped carbon nanofiber mats can be prepared by the addition of cobalt acetate to the polyacrylonitrile/DMF electrospun solution. Wastewater obtained from food industries was utilized as the anolyte as well as microorganisms as the source in single-chamber batch mode microbial fuel cells. The results indicated that the single Co-free carbon nanofiber mat was not a good anode in the used microbial fuel cells. However, the generated power can be distinctly enhanced by using double active layers of pristine carbon nanofiber mats or a single layer Co-doped carbon nanofiber mat as anodes. Typically, after 24 h batching time, the estimated generated power densities were 10, 92, and 121 mW/m2 for single, double active layers, and Co-doped carbon nanofiber anodes, respectively. For comparison, the performance of the cell was investigated using carbon cloth and carbon paper as anodes, the observed power densities were smaller than the introduced modified anodes at 58 and 62 mW/m2, respectively. Moreover, the COD removal and Columbic efficiency were calculated for the proposed anodes as well as the used commercial ones. The results further confirm the priority of using double active layer or metal-doped carbon nanofiber anodes over the commercial ones. Numerically, the calculated COD removals were 29.16 and 38.95% for carbon paper and carbon cloth while 40.53 and 45.79% COD removals were obtained with double active layer and Co-doped carbon nanofiber anodes, respectively. With a similar trend, the calculated Columbic efficiencies were 26, 42, 52, and 71% for the same sequence. [ABSTRACT FROM AUTHOR]

Silver‐zinc (Ag–Zn) batteries are a promising battery system for flexible electronics owing to their high safety, high energy density, and stable output voltage. However, poor cycling performance, low areal capacity, and inferior flexibility limit the practical application of Ag–Zn batteries. Herein, we develop a flexible quasi‐solid‐state Ag–Zn battery system with superior performance by using mild electrolyte and binder‐free electrodes. Copper foam current collector is introduced to impede the growth of Zn dendrite, and the structure of Ag cathode is engineered by electrodeposition and chloridization process to improve the areal capacity. This novel battery demonstrates a remarkable cycle retention of 90% for 200 cycles at 3 mA cm−2. More importantly, this binder‐free battery can afford a high capacity of 3.5 mAh cm−2 at 3 mA cm−2, an outstanding power density of 2.42 mW cm−2, and a maximum energy density of 3.4 mWh cm−2. An energy management circuit is adopted to boost the output voltage of a single battery, which can power electronic ink display and Bluetooth temperature and humidity sensor. The developed battery can even operate under the extreme conditions, such as being bent and sealed in solid ice. This work offers a path for designing electrodes and electrolyte toward high‐performance flexible Ag–Zn batteries. [ABSTRACT FROM AUTHOR]

Nanowires synthesized from metal oxides exhibit better conductivity than nanoparticles due to their greater aspect ratio which means that they can transmit electrons over longer distances; in addition, they are also more widely available than pili because their synthesis is not affected by the bacteria themselves. However, there is still little research on the application of metal oxides nanowires to enhance power generation of microbial fuel cells (MFC). In this study, a simple hydrothermal synthesis method was adopted to synthesize α-FeOOH nanowires on carbon paper (α-FeOOH-NWs), which serve as an anode to explore the mechanism of power generation enhancement of MFC. Characterization results reveal α-FeOOH-NWs on carbon paper are approximately 30–50 nm in diameter, with goethite structure. Electrochemical test results indicate that α-FeOOH nanowires could enhance the electrochemical activity of carbon paper and reduce the electron transfer resistance (R ct). Furthermore, α-FeOOH-NWs made the power density of MFC 3.2 times of the control device. SEM result demonstrates that nanowires are beneficial to the formation of biofilms and increase biomass on the electrode surface. Our results demonstrate that nanowires not only improve the electrochemical activity and conductivity of carbon paper but also facilitate the formation of biofilms and increase the biomass of the anode surface. These two mechanisms work together to boost extracellular electron transfer and power generation efficiency of MFC with α-FeOOH-NWs. Our study provides further evidence for the electrical conductivity of metal nanowires, promoting their potential applications in electricity generation such as MFC or other energy development fields. • α-FeOOH nanowires enhanced electron transfer rate and reduced Rct. • α-FeOOH nanowires are beneficial to the formation of biofilms. • α-FeOOH nanowires made the power density of MFC 3.2 times than the control. [ABSTRACT FROM AUTHOR]

Abstract: Gold is among the highly conductive and stable materials, which are ideal anodes for microbial fuel cells (MFCs). However, previous studies have shown that bare gold surface is recalcitrant for the colonization of some exoelectrogens, e.g., Shewanella putrefacians. In this work, the problem regarding the poor bio-compatibility of gold as an anode material was sorted out through coupling it with carbon paper. A new composite anode material was fabricated through sputtering gold layer homogeneously on carbon paper matrix. Results of cyclic voltammetry and electrochemical impedance spectroscopy in Fe(CN)6 3−/4− solution demonstrated better electrochemical performance of the carbon paper–gold (C–Au) composite than either carbon paper or bare gold, when they were used in MFCs. With Shewanella oneidensis MR-1 as the inoculum, the C–Au anode-based MFC produced total electric charges higher than the carbon-paper-anode-based MFC by 47%. The cyclic voltammetry analysis and the scanning electron microscopy observation showed that the MR-1 biofilm growth was accelerated when the carbon paper surface was sputtered with gold. Utilization of such a carbon paper–gold composite significantly enhanced the MFC performance. [ABSTRACT FROM AUTHOR]

A flexible, lightweight, and high conductivity current collector is the key element that enables fabrication of a high-performance, flexible lithium-ion battery. Here, we report a thin, lightweight, and flexible lithium-ion battery that uses graphite papers deposited with nano-sized metallic layers as the current collector, LiFePO4 and Li4Ti5O12 as the cathode and anode materials, respectively, and a PE membrane soaked in LiPF6 as the separator. Using thin, flexible graphite paper as a substrate for the current collector instead of a rigid, heavy metal foil enables us to demonstrate an ultra-thin lithium-ion battery (total thickness including encapsulation layers of less than 250 μm) that also features a light weight and high flexibility. [ABSTRACT FROM AUTHOR]

Porous 3D composite materials are interesting anode electrodes for single chamber microbial fuel cells (SCMFCs) since they exploit a surface layer that is able to achieve the correct biocompatibility for the proliferation of electroactive bacteria and have an inner charge transfer element that favors electron transfer and improves the electrochemical activity of microorganisms. The crucial step is to fine-tune the continuous porosity inside the anode electrode, thus enhancing the bacterial growth, adhesion, and proliferation, and the substrate's transport and waste products removal, avoiding pore clogging. To this purpose, a novel approach to synthetize a 3D composite aerogel is proposed in the present work. A 3D composite aerogel, based on polydimethylsiloxane (PDMS) and multi-wall carbon nanotubes (MWCNTs) as a conductive filler, was obtained by pouring this mixture over the commercial sugar, used as removable template to induce and tune the hierarchical continuous porosity into final nanostructures. In this scenario, the granularity of the sugar directly affects the porosities distribution inside the 3D composite aerogel, as confirmed by the morphological characterizations implemented. We demonstrated the capability to realize a high-performance bioelectrode, which showed a 3D porous structure characterized by a high surface area typical of aerogel materials, the required biocompatibility for bacterial proliferations, and an improved electron pathway inside it. Indeed, SCMFCs with 3D composite aerogel achieved current densities of (691.7 ± 9.5) mA m−2, three orders of magnitude higher than commercial carbon paper, (287.8 ± 16.1) mA m−2. [ABSTRACT FROM AUTHOR]

Abstract Lithium-Sulfur (Li-S) batteries are known for their high energy density and cost-effectiveness. However, the Li-S chemistry is a challenging topic due to the shuttle effect and the use of highly reactive lithium metal anode. To solve these issues, ultra-lightweight multilayered graphene coated paper separator is proposed as an interlayer. The interlayer is firstly coated on nickel foil by Chemical Vapor Deposition (CVD) method followed by transferring to the paper by fishing process. By employing this unique technique, a very light (∼8 μg/cm2) graphene coating layer is obtained which does not further imply lowering the entire energy density of the cell. As a whole, the cell with graphene coated paper exhibits 610 mAh/g discharge capacity at C/5 after 100 cycles, while the cell without interlayer exhibits much poorer performance. The improved performance is mostly associated with the interaction between graphene and polysulfide species which is proven by X-Ray Photoelectron Spectroscopy measurement as well as the excellent electronic conductivity of graphene layer which behaves as a secondary current collector resulting the cell resistance decrease. Graphical abstract Image 1 Highlights • Graphene is conformally coated on nickel foil by Chemical Vapor Deposition. • Graphene is transferred to paper in water by fishing process. • Graphene coating has one of the lowest weight (8 μg/cm2) used in Li-S batteries. • 610 mAh/g discharge capacity is gained after 100 cycles with graphene coated paper. [ABSTRACT FROM AUTHOR]

Microbial fuel cells (MFCs) can evolve in a viable technology if environmentally sound materials are developed and became available at low cost for these devices. This is especially important not only for the designing of large wastewater treatment systems, but also for the fabrication of low-cost, single-use devices. In this work we synthesized membranes by a simple procedure involving easily-biodegradable and economic materials such as poly (vinyl alcohol) (PVA), chitosan (CS) and the composite PVA:CS. Membranes were chemical and physically characterized and compared to Nafion®. Performance was studied using the membrane as separator in a typical H-Type MFCs showing that PVA:CS membrane outperform Nafion® 4 times (power production) while being 75 times more economic. We found that performance in MFC depends over interactions among several membrane characteristics such as oxygen permeability and ion conductivity. Moreover, we design a paper-based micro-scale MFC, which was used as a toxicity assay using 16 μL samples containing formaldehyde as a model toxicant. The PVA:CS membrane presented here can offer low environmental impact and become a very interesting option for point of need single-use analytical devices, especially in low-income countries where burning is used as disposal method, and toxic fluoride fumes (from Nafion®) can be released to the environment. [ABSTRACT FROM AUTHOR]

Space charge has close relation with the trap distribution in the insulation material. The phenomenon of charges trapping and detrapping has attracted significant attention in recent years. Space charge and trap parameters are effective parameters for assessing the ageing condition of the insulation material qualitatively. In this paper, a new method for calculating trap distribution based on the double exponential fitting analysis of charge decay process and its application on characterizing the trap distribution of oil impregnated insulation paper was investigated. When compared with the common first order exponential fitting analysis method, the improved dual-level trap method could obtain the energy level range and density of both shallow traps and deep traps, simultaneously. Space charge decay process analysis of the insulation paper immersed with new oil and aged oil shows that the improved trap distribution calculation method can distinguish the physical defects and chemical defects. The trap density shows an increasing trend with the oil ageing, especially for the deep traps mainly related to chemical defects. The greater the energy could be filled by the traps, the larger amount of charges could be trapped, especially under higher electric field strength. The deep trap energy level and trap density could be used to characterize ageing. When one evaluates the ageing condition of oil-paper insulation using trap distribution parameters, the influence of oil performance should not be ignored. [ABSTRACT FROM AUTHOR]

The relation between ageing and space charge is a hot area, but there is little direct evidence. In this paper, oil-paper samples were exposed to 20-kV/mm DC electrical field, 130°C temperature or both 20-kV/mm DC electrical field and 130°C temperature separately. Charge transport through them was analyzed at intervals by the pulsed electroacoustic (PEA) method. We find that the quantity of trapped charge increases with stressing durations, no matter what kind of stress oil-paper is exposed to. That indicates that energy release through space charge movement, such as charge trapping/detrapping and recombination, is another reason for traps generation besides deterioration caused by thermal ageing. However, because the difference in cellulose degradation mechanism among them, charge transport dynamics are thereby different under different stressing conditions. Space charge accumulates faster inner electrothermally stressed oil-paper than that inner another two kinds of oil-paper, and the sign of trapped charge is positive if oil-paper is electrically or electro-thermally stressed. The latter behavior is discussed in terms of electromagnetic dynamics due to cavity within oil-paper once there is external electric field. [ABSTRACT FROM PUBLISHER]

Wrinkled-paper-like ZnCo 2 O 4 nanoflakes were synthesized by a facile hydrothermal synthesis and a post-annealing treatment. As an anode for lithium-ion batteries, it exhibits high capacity, excellent cyclability and ultrahigh rate performance. A reversible capacity of 1138 mAh g −1 at 1 A g −1 was obtained after 500 cycles. After cycled at current densities from 0.2 to 25.6 A g −1 , the reversible capacity can recover to 1089 mAh g −1 at 0.2 A g −1 . It has been demonstrated that the wrinkled-paper-like ZnCo 2 O 4 nanoflakes are promising for application as future energy storage units. [ABSTRACT FROM AUTHOR]

• The surface of Cu 2+1 O is found to be wettable to molten Li for the first time. • The lithiophilicity origin of Cu 2+1 O surface was investigated. • The lithiophilicity is a key to fabricate and stabilize Li metal anodes. • An approach for mass production was proposed to obtain stable Li composite anodes. • The fabricated composite anodes showed excellent electrochemical performance. The carbon-based materials are promising hosts for metallic Li owing to their merits of excellent chemical stability, high porosity and electrical conductivity, as well as lightweight. Nevertheless, homogeneously pre-depositing Li into the carbon hosts remains a challenge owing to the inherited lithiophobic surface of carbon materials. In this contribution, we found that the Cu 2+1 O was lithiophilic and the origin of the lithiophilicity of Cu 2+1 O was investigated. Furthermore, a facile approach was presented to uniformly coat a thin Cu 2+1 O layer onto commercial carbon papers (CPs) to modify the surfaces of CPs into lithiophilic and after molten Li infusion, the Li-Cu 2+1 O-CP composite anode was fabricated. The CP could accommodate the huge volume change of Li and suppress the Li dendrite growth during cycling. As a result, the Li-Cu 2+1 O-CP composite anode delivered a stable repeating Li plating and stripping behavior (500 cycles at 10 mA cm−2 with 3 mAh cm−2Li) based on symmetric cell, as well as enhanced rate capability and cycling stability (97% capacity retention after 500 cycles) in full cells integrated with a commercial LiFePO 4 cathode. [ABSTRACT FROM AUTHOR]

Herein, an environment friendly paper-based biobattery is demonstrated that yields a power of 12.5 W/m 3 . Whatman filter papers were used not only as support for electrode fabrication but also as separator of the biobattery. To provide electrical conductivity to the paper-based cathode and anode, commercially available eyeliner containing carbon nanoparticles and Fe 3 O 4 was directly employed as conductive ink without any binder. With an instant start-up, the as-fabricated biocompatible electrodes could hold bacteria in an active form at the anode allowing chemical oxidation of organic fuel producing current. The facile process delineated here can be employed for the tailored electrode fabrication of various flexible energy harnessing devices. [ABSTRACT FROM AUTHOR]

Oil-paper compound insulation has been widely used in power transformers for quite a long time because of its good performance. The paper insulation degrades under the combined stresses of thermal, electrical and chemical stresses during routine operations, resulting in the reduction of its degree of polymerization (DP) and hence its mechanical and electrical strength. Space charges in a dielectric material have a close relation to its electrical performance. Therefore, in this work, the effect of paper-aged states (with different DP values) on the space charge behavior in oil-impregnated paper insulation is investigated, and the pulsed electro-acoustic (PEA) method is used for the space charge distribution measurement. In order to achieve this purpose, new oil-impregnated paper samples are thermally-accelerated aged for different time interval to obtain different DP values, and then the residual oil in each sample is removed, and the Kraft paper samples are dried in a vacuum dry oven. After that, all paper samples are impregnated with new oil, and PEA measurements are performed at room temperature. The experimental results show that, when the external dc voltage is applied on the oil-paper sample, homo-charge injection occurs for all samples. The samples with different aging states exhibit quite different space charge characteristics for both voltage-on and voltage-off conditions. When the aged states are worse, for voltage-on condition, more charges are induced at cathode and anode, as well as more space charges are accumulated in the bulk. For voltage-off condition, the space charge decay rate shows no obvious change for different aged samples. [ABSTRACT FROM PUBLISHER]

Fluoroethylene carbonate (FEC)-based electrolytes using FEC as the co-solvent (50 wt%) are investigated and compared with the electrolyte using FEC as the additive (10 wt%) for freestanding Si-carbon nanotubes (CNTs) composite paper anodes for Li-ion batteries. The ethylene carbonate (EC)-free FEC-based electrolyte is found to achieve higher specific capacity and better capacity retention in terms of long-term cycling. After 500 cycles, the capacity retention of the cell using diethyl carbonate (DEC)-FEC (1:1 w/w) is increased by 88% and 60% compared to the cells using EC-DEC-FEC (45:45:10 w/w/w) and EC-FEC (1:1 w/w), respectively. Through SEM-EDX and XPS analyses, a possible reaction route of formation of fluorinated semicarbonates and polyolefins from FEC is proposed. The inferior cell performance related to the EC-containing electrolytes is likely due to the formation of more polyolefins, which do not favor Li ion migration. [ABSTRACT FROM AUTHOR]

Vanadium nitride (VN) is a promising anode material for asymmetric supercapacitors (ASCs) owing to its high theoretical pseudocapacitance and high electrical conductivity. However, the instability of VN in aqueous electrolytes hinders practical applications. In this study, VN nanowires (VNNWs) were hybridized with nitrogen-doped graphene (NG) to fabricate a freestanding VNNW/NG porous paper electrode. The prepared paper electrode exhibited excellent electrochemical performance with an outstanding specific capacitance of 244.7 F·g−1 at 0.5 A·g−1 and a rate capability of 70.7% capacitance retention as the current density increased from 1 to 10 A·g−1. Moreover, the VNNW/NG anode presented remarkable cycling stability of 87% capacitance retention over 10,000 cycles at 5 A·g−1. Encapsulation with NG significantly improved the stability of VNNWs, overcoming their major drawbacks (i.e. , low cycling stability). Also, the hierarchical pore structure of the VNNG/NG could facilitate high energy and power density capabilities. An ASC assembled with VNNW/NG anode and nickel oxide/reduced graphene oxide (NiO/rGO) cathode presented high energy density of 20.2 Wh·kg−1 at power density of 850.0 W·kg−1. Thus, we suggest that the design strategy of the fabricated porous paper electrode could be utilized to produce high-performance anode materials for application in supercapacitors. • Preparation of freestanding and binder-free paper electrodes for asymmetric supercapacitor (ASC) anode. • Encapsulation of vanadium nitride nanowire (VNNW) in nitrogen-doped graphene (NG). • VNNW/NG anode presented remarkable cycling stability of 87% capacitance retention over 10,000 cycles at 5 A·g−1. • ASC device presented high energy density of 20.2 Wh·kg−1 at power density of 850.0 W·kg−1. [ABSTRACT FROM AUTHOR]

Space charge is a threat to insulation materials and oil-paper insulation gradually degrades in service. The degradation of cellulose affects space charge formation, accumulation and dissipation, and the presence of space charge affects the performance of dielectric. In this paper, the effect of thermal aging on space charge behaviors and other properties including permittivity, conductivity, and tensile strength was investigated. Oil-paper samples were aged at a hot spot temperature (180?). During thermal aging, space charge distribution was measured at a regular interval at room temperature. And the pulse electro-acoustic (PEA) method was used for space charge measurement. The results showed that the thermal aging at hot spot temperature caused increase of conductivity and tensile strength degradation. The permittivity increased at the beginning but then it decreased, while dissipation factor showed an upward trend. Besides these, trap distribution and carriers characteristics were also affected. The formations of space charge of unaged and aged oil paper were consequently different under low electric field. Due to the generation of traps by the degradation of cellulose, more charge, especially positive charge was trapped, but the increased traps mostly were shallow traps. Based on the Schottky model, a correlation between space charge injection and the permittivity was drawn. This, together with the appearance of positive bulk charge could be used for oil paper aging status diagnosis. [ABSTRACT FROM AUTHOR]

Silicon has been considered as one of the most promising anode materials for the next generation lithium-ion battery due to its high theoretical capacity, but large volume changes during the electrochemical cycling limit its commercial application. In this study, we report the synthesis of silicon carbide @ silicon core–shell nanowires on carbon paper and their application in lithium-ion batteries. The hybrid nano-structures are fabricated via a two-step chemical vapor deposition method and directly used as the working electrode without any additional binder, exhibiting high specific capacity, high coulombic efficiency and good cycling stability. After 50 cycles, the discharge capacities still remain 2837 and 1809 mAh g −1 at the rates of 0.1C and 0.5C, respectively. Furthermore, we also study the influence of the growth time of SiC NWs and the thickness of Si film on the lithium-ion batteries' performance, and propose the possible method to further improve the battery performance. [ABSTRACT FROM AUTHOR]

The evolution of the three-dimensional (3D) morphology of a Si-based electrode upon cycling (1st discharge, 1st charge and 2nd discharge) is studied by in-situ synchrotron X-ray tomography. The Si-based electrode is constituted of silicon/carbon black/carboxymethylcellulose (Si/CB/CMC) embedded in a commercial carbon fiber paper, acting as a flexible 3D current collector. Its initial areal discharge capacity is 4.9 mAh cm −2 . A reconstructed volume of 293 × 293 × 137 μm 3 is analyzed with a resolution of ∼0.3 μm. Three phases are identified: (i) the solid phase (C fibers + Si + CB + CMC), (ii) the electrolyte phase (pores filled with electrolyte) and (iii) the gas phase (electrolyte-free pores). Their respective volume fraction, size distribution and connectivity, and also the dimensional changes of the electrode along the three axes are quantified during cycling. At the beginning of the 1st discharge (lithiation), the formation of gas channels attributed to the reductive electrolyte decomposition is observed. During the 1st charge, large cracks are formed through the electrode, which reclose during the subsequent discharge. The electrode expansion/contraction due to the Si volume change is partially irreversible, occurs mainly in the transverse direction and is much larger in the bottom part of the electrode. [ABSTRACT FROM AUTHOR]

Repeated impulses have long been considered to affect the insulation properties of electrical equipment. This interesting but rarely studied phenomenon may pose great risks to the reliable operation of power equipment. Therefore, in this work, we focus on the accumulative effect of repeated lightning impulses on the oil-impregnated paper (OIP) used in power transformers. Specifically, we study the effect of space charge on the accumulative characteristics of OIP. A repetitive impulse accumulating test platform was set up, and the tests were conducted to obtain the accumulative characteristics of OIP under repeated lightning impulses. The accumulative characteristics of OIP with various interval time were experimentally identified to study the influence of interval time on the accumulative effect. Then, space charge in OIP samples were investigated using the pulsed electro-acoustic technique. Charge behavior in OIP was analyzed under different conditions, i.e., changing the applied times, amplitude and interval time of the applied lightning impulses. Charge injection and transport occurred during lightning impulse accumulation. The increased application of lightning impulses, high applied voltage, and short interval time contributed to the accumulation and transport of space charges. At last, the possible mechanisms of the accumulative effect are discussed in this article based on the experimental results. [ABSTRACT FROM AUTHOR]

Space charge has received much attention recently because an understanding of space charge in oil-paper insulation is useful for the design of converter transformers. This paper presents a study of space charge dynamics at the physical interface using the pulsed electroacoustic (PEA) method. After sample inversion, space charge in the vicinity of semiconductor electrode could be clearly observed when the sample is under depolarization. When an unexposed sample was placed next to a previously polarized one, negative charge appeared at the dielectric interface. These results indicated that there were other reasons in addition to acoustic loss that led to space charge distribution distortion. As regards the dielectric interface, it was found that an electrical double layer was formed at the interface, and the space charge sign was dependent upon the polarity of applied voltage. Space charge behavior at the interface depended on several aspects of the status of the interface, and during voltage polarity reversal, the interface was a weak point of the insulation. [ABSTRACT FROM AUTHOR]

Abstract: With the aim to shed light on the effective role of carbon paper (CP) substrate-current collector on the constant capacity delivered over cycling by different types of anodes for lithium-ion batteries, Cu6Sn5/CP, Sn2Mn/CP and Sn/CP, we analyzed the voltage profiles of repeated galvanostatic charge/discharge cycles of these electrodes in terms of differential capacity (dQ/dV) versus voltage, comparatively with those of bare CP, and their structural modification by X-ray diffraction analysis before and after cycling. The results of this study demonstrate that Sn, in high mass loading electrodes, gradually loses the electric contact with the current collector and Sn2Mn/CP electrodes show a gradual degradation of Sn2Mn. In both cases, CP is involved in the electrochemical process by contributing to the delivered capacity of these electrodes which display stability over 100 of cycles. Furthermore, the analysis of the Cu6Sn5/CP electrodes, which for high mass loading were able to provide constant capacity significantly higher than that the bare CP supplied and to remain stable for a number of cycles higher than Sn and Sn2Mn did, indicates that CP effect on the Cu6Sn5 cycling stability is moderate as it concerns the contribution to capacity but it is fundamental for the electric contact. Hence, CP can be considered an excellent substrate-current collector only for intermetallic compounds like Cu6Sn5 that contains an inert metal able to buffer the volume changes accompanying the lithiation processes which provide compounds isostructural with the unlithiated intermetallic up to 2.6Li/Sn atomic ratio (Li13Cu6Sn5). [Copyright &y& Elsevier]

Highlights: [•] Graphene was covalently modified to have polycaprolactone brushes on the surface. [•] Functionalized graphene paper exhibited super-toughness and high flexibility. [•] Lithium ion battery anode fabricated from the paper showed excellent capacity. [Copyright &y& Elsevier]

As the temperature gradient always exists in the insulation of power equipment, the influence of temperature gradient on oil-impregnated paper insulation is studied by experiments and simulation. It's found that in the both single-layer and double-layer structures, the heterocharges always appear near the lower temperature electrode, and increase with the enhancement of temperature gradient and field stress, resulting in more considerable field distortion. However, there are more heterocharges in the single-layer samples while the field distortion is more severe in double-layer samples. Numerical simulations were carried out to investigate the mechanism of temperature gradient effect. It is indicated that the space charge accumulation is mainly due to the temperature dependence of the charge injection and conduction. The behavior of interface charges can be well described by assuming an energy barrier for charge transportation at the interface. [ABSTRACT FROM AUTHOR]

Aqueous zinc (Zn) batteries with Zn metal anodes are promising clean energy storage devices with intrinsic safety and low cost. However, Zn dendrite growth severely restricts the use of Zn anodes. To effectively suppress Zn dendrite growth, we propose a bilayer separator consisting of commercial butter paper and glass fiber membrane. The dense cellulose-based butter paper (BP) with low zincophilicity and high mechanical properties prevents the pore-filling behavior of deposited Zn and related separator piercing, effectively suppressing the Zn dendrite growth. As a result, the bilayer separators endow the Zn||Zn symmetrical batteries with a superlong cycling life of Zn anodes (over 5000 h) at 0.5 mA cm -2 and the full batteries enhanced capacity retention, demonstrating the advancement of the bilayer separator to afford excellent cyclability of aqueous metal batteries. [ABSTRACT FROM AUTHOR]

Abstract: Free-standing hybrid papers were fabricated by the vacuum-assisted filtration of graphene nanosheets (GNS) and carbon nanotubes (CNTs) both suspended in water, an approach that is environmentally benign. The CNTs are randomly dispersed between the GNS and hence, the hybrid papers exhibit high mechanical strength and flexibility even after being annealed at 800 °C. Electrochemical properties of the hybrid papers are strongly dependent on the CNT/GN ratios. Highest lithium ion storage capacities were obtained in the paper with a CNT/GN ratio of 2:1. The initial reversible specific capacities are ∼375 mAh g−1 at 100 mA g−1. The capacities remain above 330 mAh g−1 after 100 cycles, which are about 100 mAh g−1 higher than those of the graphene paper with nearly the same mass. The improved capacities were attributed to the contribution of the CNTs, which prevent restacking of the GNS, increase cross-plane electric conductivity of the paper and simultaneously, store Li ions. These results suggest that graphene–CNT hybrid paper has a high potential to be used as collector and binder free anodes for lithium ion batteries. [Copyright &y& Elsevier]

Abstract: A free-standing SnO2/reduced graphene oxide (re-G) hybrid paper has been successfully fabricated by a facile vacuum filtration approach through a uniformly dispersed SnO2 nanoparticle and graphene oxide mixed solution. As potential anode material for high power and energy applications, the hybrid nanostructures were directly evaluated as anode for rechargeable lithium ion batteries without adding any polymer binder, conductive additives or current collectors. And the composite exhibits a greatly enhanced synergic effect with extremely high energy storage stability of 700mAhg−1 after 100 cycles benefiting from the advanced structural features. [Copyright &y& Elsevier]

Abstract: Free-standing heterogeneous hybrid papers based on mesoporous γ-MnO2 particles and acid-treated single-walled carbon nanotubes (a-SWCNTs) for lithium-ion battery anodes are successfully prepared by simple vacuum filtration. The mesoporous γ-MnO2 particles with high surface areas are well dispersed throughout these anodes by being bound in nanoporous a-SWCNT networks. Furthermore, these anodes exhibit a high electrical conductivity of 2.5 × 102 S cm−1 with high flexibility, which makes them substrate- and binder-free. For 50 wt% mesoporous γ-MnO2 particle-loaded anodes, a high reversible capacity of 934 mA h g−1 (0.01–3.0 V) is maintained after 150 cycles. [Copyright &y& Elsevier]

Abstract: A flexible battery is printed on paper by screen-printing a zinc/carbon/polymer composite anode on one side of the sheet, polymerising a poly(3,4-ethylenedioxythiophene) (PEDOT) cathode on the other side of the sheet, and applying a lithium chloride electrolyte between the two electrodes. The PEDOT cathode is prepared by inkjet printing a pattern of iron(III)p-toluenesulfonate as a solution in butan-1-ol onto paper, followed by vapour phase polymerisation of the monomer. The electrolyte is prepared as a solution of lithium chloride and lithium hydroxide and also applied by inkjet printing on to paper, where it is absorbed into the sheet cross-section. Measurements on a zinc/carbon-PEDOT/air battery in a similar configuration on a polyethylene naphthalate substrate shows a discharge capacity of up to 1.4mAhcm−2 for an initial load of 2.5mg zinc, equivalent to almost 70% of the zinc content of the anode, which generates 0.8V at a discharge current of 500μA. By comparison, the performance of the paper-based battery is lower, with an open-circuit voltage of about 1.2V and a discharge capacity of 0.5mAhcm2. It appears that the paper/electrolyte combination has a limited ability to take up anode oxidation products before suffering a reduction in ionic mobility. The effects of different zinc/carbon/binder combinations, differences in application method for the zinc/carbon composite and various electrolyte compositions are discussed. [Copyright &y& Elsevier]

Two dimensional nanosheets, such as graphene and metal disulfides, have attracted a great deal of attention as anode materials for lithium-ion batteries, owing to their unique capability for lithium-ion storage. In this work, we integrate graphene and MoS 2 nanosheets into a free standing film form using a simple vacuum filtration method. As-prepared composite film could be readily employed as a binder- and carbon-free anode for lithium-ion batteries, removing the polymeric binders and conductive carbon additives that are required for the preparation of conventional electrodes. In addition, the interconnected structure of graphene and MoS 2 sheets provide a good electrical conductivity to the entire film electrode. When tested electrochemical performance as an anode for lithium-ion batteries, the composite film electrode exhibits superior performance compared to the exfoliated MoS 2 electrode, such as 65.8% capacity retention at a high current rate of 1000 mA g −1 and 91.1% capacity retention after 100 cycles. [ABSTRACT FROM AUTHOR]