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Structural energy storage technology is a potential solution to reduce the weight of electrical energy storage systems. Zn ion fiber batteries are important for this technology given their flexibility, safety, and lightweight. As a component of fiber battery production, the structural design of fiber electrodes is caught in a dilemma. Fiber electrodes with core are difficult to prepare continuously, while fiber electrodes without core have unsatisfactory mechanical strength. Herein, a wet spinning method is used to prepare fiber electrodes with core continuously at a speed of 25 mm s−1. Raw commercial vanadium pentoxide powders, acetylene black, and polyvinylidene fluoride are mixed into a slurry. A special tapered concave nozzle is designed to make the slurry saturate the core fully and be extruded well. Therefore, the fiber electrodes own a high ultimate tensile strength of 303 MPa and maintain the microstructure after 5000 bending cycles. The Zn ion fiber batteries exhibit a specific capacity of 134 mAh g−1 at 0.1 A g−1 after 100 cycles. This work shows a simple and efficient way to prepare fiber electrodes with core, which provides a new strategy for flexible electronic manufacturing and structural energy storage technology. [Display omitted] • Vanadium pentoxide coated on the silver-plated yarn is used in the Zn ion batteries. • A wet spinning method is designed to prepare fiber electrodes simply. • A unique tapered and concave nozzle is used to improve the extrusion process. • Fiber electrodes with core exhibit a good tensile strength and electrical performance. • Finite element simulation is used to investigate the fluid in the extrusion process. [ABSTRACT FROM AUTHOR]

Fast charging of graphite is important for the popularization of electric vehicles. KOH-etched graphite with a good initial fast-charging capacity cannot be maintained during long-term fast charging. Additionally, the existing mechanism of hole creation contradicts several facts. Therefore, there is an urgent need to improve the performance and update related mechanisms of KOH-etched graphite. The etching process under mild conditions is studied, and the changes in graphite after the reaction are characterized. Three reactions involving carbon atoms at different sites are designed, and the interactions between graphite and the KOH solution are studied via quantum chemical calculations. Activated graphite (AG) is obtained by etching graphite with a KOH solution, and a nanomicro composite electrode is constructed with carbon black (CB). Only a few carbon atoms at abnormal sites can participate in the reaction under mild conditions, and a new mechanism of edge activation is provided. The AG-CB electrode with a high areal capacity exhibits excellent fast-charging capability, and a pouch cell with AG-CB and LiNi 0.5 Co 0.2 Mn 0.3 O 2 retains ∼80 % of the initial capacity after 500 cycles at a high charging rate of 3C (20 min). This cost-effective and time-efficient approach is crucial for accelerating the commercialization of high-energy-density and fast-charging batteries. Both effects jointly increase the fast-charging ability of graphite. The mild reaction conditions protect the vast majority of carbon atoms and maintain the stability of the material structure; only a few carbon atoms at abnormal positions (such as defects and edge sites) can participate in the reaction, which introduces holes on basal planes, increasing the migration paths for Li ions, and optimizes edge structures, decreasing the Li-ion intercalation impedance. [Display omitted] • A new mechanism of edge activation is proposed and supported. • Mild etching is an ideal way to enhance the fast-charging capability of graphite. • A superior KOH-etched graphite is acquired by constructing a nano-microscale structure with carbon black. • The pouch cell (>2 Ah) retains ∼80 % of the initial capacity after 500 cycles at 3C. [ABSTRACT FROM AUTHOR]

Black phosphorus (BP) is a promising material with a high theoretical specific capacity and high carrier mobility. Nevertheless, the anode volume expansion of BP during charging and discharging represents a significant obstacle to its further development in sodium-ion batteries (SIBs) which reduces their properties in terms of specific capacity and cycling stability. To solve the problem, a series of BP and hard carbon (BP-HC) composites are prepared with different mass ratios (7:3, 5:5, and 4:6) by a simple ball milling method. Various characterization techniques are used to analyze the microstructures and binding conformations of the materials. It is found that a strong interaction between BP and HC through the formation of phosphorus-carbon (P–C) and phosphorus-oxygen-carbon (P–O–C) bonds which benefits the electrochemical performance of SIBs. Among the three BP-HC anodes, the BP-HC-46 anode shows the best cycling stability, with a high initial discharge specific capacity of 2448.8 mAh g−1 at a current density of 0.1 A g−1 and a reversible capacity of up to 1842.2 mAh g−1 after 50 cycles with a retention rate of 97.4 % (compared to the second discharge specific capacity of 1890.6 mAh g−1). This study proposes a straightforward method for synthesizing BP-HC anode composites in SIBs. [Display omitted] • BP-HC nanocomposites were fabricated by a straightforward ball milling process. • Strong P–C and P–O–C bonds are formed between BP-HC Nanocomposite. • The ratio of BP-HC composites with the best electrochemical performance is 4:6. • The anode shows good cyclic stability and an initial capacity of 2448.8 mAh g−1. • The fast Na + diffusion kinetics and capacitance-dominated behavior were elucidated. [ABSTRACT FROM AUTHOR]

The development of efficient and stable catalysts is the key to promote the application of fuel cells. The modified carbon support can improve the performance of platinum (Pt) -based catalyst by improving the Pt dispersion. The effect of surface oxygen content and pore structure on modified carbon support are studied to explain their respective role in Pt dispersion. With three designed pretreatment routes, it is found that surface oxygen content on carbon black (CB) negatively correlates with the Pt dispersion, while newly-generated 2–4 nm mesopores play a positive role. The modified CBs with low surface oxygen content and more 2–4 nm mesopores can drive Pt nanoparticles to reach smaller diameters and narrower diameter regions. The catalysts supported by the CBs modified in solid-phase at 700 °C (Pt/CB-S-700) have best performance (336 mA mg Pt −1, 14 % degradation after 30k cycles). In the membrane electrode assembly (MEA) , the maximum power density of MEA-Pt/CB-S-700 is 0.907W/cm2, which is higher than that of MEA-Pt/C (0.875 W/cm2). After accelerated degradation test (ADT) , it also shows good durability. This optimization method of carbon support can effectively improve the performance of catalysts, which provides an effective way for the practical application of catalysts in fuel cell. • The effect of surface oxygen content of carbon support on Pt dispersion is studied. • The influence of pore structure of carbon support on Pt dispersion is summarized. • The differences between the three routes of solid-liquid-gas were compared. • The maximum power density is increased by 3.7 % compared with commercial Pt/C. [ABSTRACT FROM AUTHOR]

The gas diffusion layer (GDL) is an essential component of a proton-exchange membrane fuel cell (PEMFC) that supplies reactant gases to catalysts by facilitating the discharge of water generated via electrochemical reaction. The GDL is primarily composed of a substrate and a microporous layer (MPL), of which the latter increases the specific contact area for electrochemical reactions with catalysts and forms a capillary pressure gradient within the GDL. The MPL primarily comprises carbon black and polytetrafluoroethylene. Carbon black is categorized into the main and additive carbon blacks. Additive carbon black is utilized to augment the specific surface area of the MPL. This study examines the effects of four GDLs with varying additive carbon black contents constituting 20%–30 % of the total carbon black content on the performance of PEMFCs. In addition, the effects of the MPL characteristics on the durability of the GDL is investigated systematically, particularly in relation to carbon corrosion and freeze/thaw conditions. Furthermore, the deterioration in the performance and properties of the GDL are investigated via an acidic solution immersion accelerated stress test. • Effects of additive carbon black on the performance of gas diffusion layer. • Effects of additive carbon black on the durability of gas diffusion layer. • Effects of newly developed carbon corrosion accelerated stress test. • Effects of newly developed freeze/thaw accelerated stress test. • Effects of newly developed acidic solution immersion accelerated stress test. [ABSTRACT FROM AUTHOR]

The development of elastic nanostructured Si-based anodes holds promise for advancing lithium-ion batteries due to the high theoretical specific capacity exhibited by Si. Combining nanostructured Si with C proves to be a successful strategy in addressing the challenges tied to the substantial volume expansion of Si during lithiation. In this work, a novel Si-based anode is fashioned through a simple and universal strategy, integrating Si nanoparticles with 1D nano-carbonaceous fillers (CPPy-NT) featuring nanotubular morphology and N atoms, and a water-based binder (poly(acrylic acid)). CPPy-NT are derived by carbonizing pre-synthesized polypyrrole nanotubes (PPy-NT). A clear correlation is established among the carbonization temperature for CPPy-NT preparation, N content in CPPy-NT, electrical conductivity, and the electrochemical performance of the ensuing Si/CPPy-NT anode. For comparative analysis, the electrochemical properties of the Si-based anode employing Super P (commercial carbon black) or PPy-NT are contrasted with those of Si/CPPy-NT. Notably, the Si/CPPy-NT anode with CPPy-NT bearing the highest amount of graphitic N sites exhibits a substantial improvement in initial charge capacity (approximately 2200 mAh g−1) and enhanced cycling stability. These findings underscore the potential to elevate the electrochemical activity of the C filler by carefully optimizing morphology, conductivity, and the incorporation of an appropriate amount of graphitic N. [Display omitted] • Synthesis of N-containing 1D nano-carbonaceous fillers with tailored properties. • Integration of N-containing 1D nano-carbonaceous fillers in Si-based anodes. • Development of novel Si/C anodes using an environmentally friendly approach. • Beneficial role of N in enhancing the electrochemical properties of Si/C anodes. [ABSTRACT FROM AUTHOR]

High energy and power density are key requirements for next-generation lithium-ion batteries. One way to improve the former is to reduce the binder and conductive additive content. Carbon black is an important additive that facilitates electronic conduction in lithium-ion batteries and affects the conductive binder domain although it only occupies 5–8% of the electrode mass. However, the function of the structure of carbon black on short- and long-range electronic contacts and pores in the electrode is still not clear and has not been systematically researched in detail. In this work, five carbon blacks with different BET surface areas, oil absorption numbers and ordered graphitic carbon content were investigated. It was found that the ratio of disordered amorphous carbon to ordered graphitic carbon in carbon blacks strongly influences the short- and long-range electrical conduction, and the BET surface area highly affects the pore structure and ionic conductivity in the electrode. Its optimum ratio, indicated by the Raman density I D / I G , is 0.93–0.95. The recommended BET surface area was 130–200 m2/g for this experimental range. The results of this study can provide guidance for the screening of carbon blacks in the lithium-ion battery industry. • Ratio of disordered to ordered carbon highly influences the electronic conduction. • BET surface area highly influences the pore structure and ionic conductivity. • Recommended ratio of carbon is 0.93–0.95 indicated by I D / I G of Raman spectroscopy. • Recommended BET surface area is 130–200 m2/g. [ABSTRACT FROM AUTHOR]

Black phosphorus (BP) has attracted extensive attention in high-rate lithium-ion batteries due to its high theoretical capacity and moderate lithiation potential. However, the large volume expansion and the low conductivity of BP nanostructures in the electrochemical cycle have inhibited the rate performance and long-term cycle stability. In this paper, by combining the glucose-assisted ball-milling and carbonization method, a black-phosphorus/carbon (BP@C) composite anodic material is developed, in which the nano-sized BP nanoparticles are homogeneously embedded in the amorphous carbon matrix. Both the phosphorus-oxygen-carbon bonds and the phosphorus-carbon bonds improve the cross-link between BP and the surface-coated carbon matrix. The unique well-embedded structure promotes the cycling stability and the rate performance of BP@C. The composite shows a high discharge specific capacity of about 1881 mAh g−1 at 0.1 A g−1, the specific capacity at 4 A g−1 is about 63% of the low current capacity, and the discharge specific capacity retains 1130 mAh g−1 after 300 charge-discharge cycles at 0.5 A g−1. Moreover, the significant role of the active unsaturated groups for building the well-embedded composite is further revealed. These results indicate that dual regulation of surface coating and structure optimization offers great potential for further optimizing phosphorus-based anode materials. • Glucose promoted BP homogeneously coated by amorphous carbon matrix. • Carbon matrix improves the conductivity and inhibits the volume expansion. • Different carbon sources influent the cross-linking of BP and the conductive matrix. [ABSTRACT FROM AUTHOR]

Tuning up transport properties of the microporous layer is an effective way to enhance mass transport in a proton exchange membrane fuel cell. The incorporation of non-spherical conductive additives in the conventional microporous layer can modify its pore structure. In this study, 5, 20, and 50 wt.% of two high aspect ratio additives, multiwall carbon nanotube and graphene nanoplatelet, are mixed with the acetylene-black carbon to systematically study their impact on ink and the final diffusion media properties. Using a bottom-up approach, the rheological properties of the ink are correlated to the mass transport resistance in the diffusion media. The ink with additives exhibits rheological properties of a less compact microstructure with large agglomerates. Whereas, a more compact agglomerated network is observed from the ink with pure acetylene black carbon nanoparticles. Graphene nanoplatelet has a dominating effect on the surface quality of the microporous layers due to its two-dimensional structure. The test results show that the microstructure formed by the synergy of acetylene black and additives can enhance ohmic and mass transport performance. 20 wt.% of the additive loading is found to be optimal and multiwall carbon nanotube shows the best fuel cell performance. • The effects of high aspect ratio additives on MPL properties are studied. • DLS data show bimodal particle size distribution for MWCNT and GNP containing inks. • Slow microstructural recovery is observed for additives due to large agglomerates. • Overall, 20 wt.% MWCNT shows the best ohmic and mass transport performance. [ABSTRACT FROM AUTHOR]

Carbon black is produced with H 2 gas from a benzene solution using the liquid-phase precipitation (LPP) mathod. Subsequently, the carbon black is heat-treated and applied as a conductive material for a supercapacitor to evaluate its performance. Carbon black produced as primary particles by the LPP reaction aggregates and grows into a secondary structure, and then crystallizes through heat treatment to form multi-polygonal nanoshells. The electrical conductivity of carbon black increased by heat treatment, but when the temperature exceeded 1500 °C, the electrical conductivity rather decreased. Following heat treatment at 1500 °C, the electrode used as the conductive material exhibits the largest specific capacitance value and the smallest IR drop. As the carbon black produced via the LPP method exhibits better conductive properties than those of Super-P, the potential to use the present method as a new hydrogen production method is confirmed. [Display omitted] • Production of hydrogen and carbon black from benzene by LPP method. • Formation of graphitized multiple nanoshells by heat treatment. • The electrical conductivity of carbon black heat-treated at 1500 °C was the highest. • Heat treatment at 1500 °C gave the largest capacitance and the smallest IR drop. • The economic feasibility of producing hydrogen with LPP was secured. [ABSTRACT FROM AUTHOR]

Although the choice of binder is crucial in determining the electrochemical performance and durability of silicon-based electrodes, the underlying mechanisms (e.g., mechanical vs . chemical) are unclear. Here, we report a study of the effects of adhesion vs . cohesion on the electrochemical behavior of silicon nanoparticle/polymeric binder/carbon black (CB) electrodes on copper conductor by multiple techniques. Two types of polymeric binders, polyvinylidene fluoride (PVDF) and sodium alginate (SA), were chosen for this study. The results show that because of a sufficiently strong interface between polymer and the copper current collector, both Si/PVDF/CB and Si/SA/CB composite electrode laminates have sufficient adhesive strength with the Cu conductor to cause cohesive failure within the electrode laminate during peel test. However, the interfacial strength between SA and silicon is significantly higher than that between PVDF and silicon, resulting in stronger cohesion within the Si/SA/CB electrode (e.g., peel strength of 78.3 N/m for Si/SA/CB electrode and 8.7 N/m for Si/PVDF/CB electrode, respectively). With a higher cohesive strength provided by a stronger binder-silicon interface, superior cell performance was ensured for Si/SA/CB electrodes. Hydrogen bonding is likely responsible for the stronger SA-Si interface since neither PVDF nor SA bonds covalently with Si according to chemical analysis. [ABSTRACT FROM AUTHOR]

Recycling high-valuable metal elements (such as Li, Ni, Co, Al and Cu elements) from scrapped lithium ion batteries can bring significant economic benefits. However, recycling and reusing anode material has not yet attracted wide attention up to now, due to the lower added-value than the above valuable metal materials and the difficulties in regenerating process. In this paper, a novel regeneration process with significant green advance is proposed to regenerate anode material recycled from scrapped Li-ion batteries for the first time. After regenerated, most acetylene black (AB) and all the styrene butadiene rubber (SBR), carboxymethylcellulose sodium (CMC) in recycled anode material are removed, and the surface of anode material is coated with pyrolytic carbon from phenolic resin again. Finally, the regenerated anode material (graphite with coating layer, residual AB and a little CMC pyrolysis product) is obtained. As expected, all the technical indexs of regenerated anode material exceed that of a midrange graphite with the same type, and partial technical indexs are even closed to that of the unused graphite. The results indicate the effective regeneration of anode material recycled from scrapped Li-ion batteries is really achieved. [ABSTRACT FROM AUTHOR]

Fundamental understanding of how processing affects composite battery electrode structure and performance is still lacking, especially for industry-relevant electrodes with low fractions of inactive material. This work combines rheology, electronic conductivity measurements, and battery rate capability tests to prove that short-range electronic contacts are more important to cathode rate capability than either ion transport or long-range electronic conductivity. LiNi 0.33 Mn 0.33 Co 0.33 O 2 , carbon black, and polyvinylidene difluoride in 1-methyl-2-pyrrolidinone represent a typical commercial electrode with <5.5 wt% inactive material. Dry-mixing carbon black with active material decreases the relative fraction of bulk (free) carbon, as shown by small angle oscillatory shear and microscopy. More free carbon leads to a stronger gel network (more long-range particle contacts) and higher electronic conductivity of the dried films. Improvements in battery rate capability at constant electrode porosity do not correlate to electronic conductivity, but rather show an optimum fraction of free carbon. Simple comparison of rate capability in electrodes with increased total carbon loading (3 wt%) shows improvement for all fractions of free carbon. These results clearly indicate that ion transport cannot be limiting and highlight the critical importance of short-range electronic contacts for controlling battery performance. [ABSTRACT FROM AUTHOR]

We report experimental evidence for the specific Li-storage at turbostratic graphene edges of a well-known and cheap Super P ® carbon black (Csp) material, which is usually used as a conductive additive in composite electrodes. Indeed, operando XRD and HR-TEM consistently demonstrate Li insertion occurs with zero expansion of graphene layer up to a composition of Li 0.4 C 6 (150 mA h/g) that is reached at 0.01 V vs. Li + /Li. 7 Li NMR substantiates these results and suggests that the weak electronic transfer from the carbon host to the intercalant could help local reorganization of the layer order as suggested by the unexpected reversible changes of the (002) Bragg peak intensity during the charge-discharge process. Our observations also indicate this insertion mechanism is kinetically favored resulting in remarkable cycling stability over 1000 cycles and power capability allowing to sustain 110 mA h/g at 8 A/g (21 C) in half cell. The capability of Csp as an efficient anode is ultimately demonstrated in a lithium hybrid capacitor against a positive electrode of activated carbon. The full cell delivers a maximum energy of 120 Wh/kg (4.3–2 V) and remarkable capacity retention over 1800 cycles. [ABSTRACT FROM AUTHOR]

In this study, we discuss the influence of various carbon supports for Pt on proton exchange membrane (PEM) fuel cell performance. Here, Pt supported on various carbon nano-forms [Pt/carbon black (Pt/CB), Pt/single-walled carbon nanotubes (Pt/SWCNT), Pt/multi-walled carbon nanotubes (Pt/MWCNT) and Pt/graphene (Pt/G)] are synthesized by a facile, single step, microwave-assisted, modified chemical reduction route. Their physical, chemical and electrochemical characteristics pertaining to oxygen reduction reaction (ORR) catalytic activity and stability in PEM fuel cell are studied in detail by various techniques and compared. The study shows that the different carbon supports does not significantly affect the Pt particle size during synthesis, but leads to different amount of defective sites in the carbon framework which influence both the availability of active metal nano-catalysts and metal-support interaction. In-situ electrochemical investigations reveal that the different carbon supports influence both ORR catalytic activity and stability of the catalyst. This is further corroborated by the demonstration of varying polarization characteristics on PEM fuel cell performance by different carbon supported Pt catalysts. This study reveals MWCNT as the most suitable carbon support for Pt catalyst, exhibiting high activity and stability for ORR in PEM fuel cell. [ABSTRACT FROM AUTHOR]

Ascorbic Acid (Vitamin C) is investigated as a renewable alternative fuel for alkaline direct liquid fuel cells (DLFCs). The environmentally- and biologically-friendly compound, l -ascorbic acid (AA) has been modeled and studied experimentally under acidic fuel cell conditions. In this work, we demonstrate that ascorbic acid is a more efficient fuel in alkaline media than in acidic media. An operating direct ascorbate fuel cell is constructed with the combination of l -ascorbic acid and KOH as the anode fuel, air or oxygen as the oxidant, a polymer anion exchange membrane, metal or carbon black anode materials and metal cathode catalyst. Operation of the fuel cell at 60 °C using 1 M AA and 1 M KOH as the anode fuel and electrolyte, respectively, and oxygen gas at the cathode, produces a maximum power density of 73 mW cm -2 , maximum current density of 497 mA cm −2 and an open circuit voltage of 0.90 V. This performance is significantly greater than that of an ascorbic acid fuel cell with a cation exchange membrane, and it is competitive with alkaline DLFCs fueled by alcohols. [ABSTRACT FROM AUTHOR]

Molybdenum disulfide (MoS 2 ) is a promising electrocatalyst for hydrogen evolution reaction (HER), however, the catalytic activity of reported MoS 2 -based materials towards HER still can't satisfy the requirement of practical application. Herein, highly conductive carbon black (CB) supported amorphous MoS 2 nanocomposite is synthesized by a facile one-pot hydrothermal process. XRD and TEM analysis proves the amorphous morphology of MoS 2 . XPS further confirms both hexagonal and orthorhombic S ligands exist in the amorphous MoS 2 . Compared with crystalline MoS 2 , amorphous MoS 2 /CB shows an onset overpotential of 78 mV and current density of 470 mA cm −2 at the overpotential of 200 mV, which is even 50% higher than that of the commercial 20% Pt/C catalyst. Furthermore, a fairly stable performance can be achieved even after 5000 CV cycles. The outstanding HER activity and stability of the amorphous MoS 2 /CB nanocomposite can be attributed to these advantages: (1) amorphous structure offers more active sites in MoS 2 ; (2) highly conductive CB reduces the charge transfer resistance (R CT ); (3) relative hydrophilic CB can largely reduce the resistance between catalyst/electrolyte interface and allows rapid mass transport; (4) electron penetration effect between amorphous MoS 2 and CB increases the intrinsic activity of amorphous MoS 2 by two orders of magnitude. [ABSTRACT FROM AUTHOR]

A three-dimensional reduced graphene oxide (3D-RGO) material has been successfully prepared by a facile hydrothermal method and is employed as the negative additive to curb the sulfation of lead-acid battery. When added with 1.0 wt% 3D-RGO, the initial discharge capacity (0.05 C, 185.36 mAh g −1 ) delivered by the battery is 14.46% higher than that of the control cell (161.94 mAh g −1 ); and the cycle life under the high-rate partial-state-of-charge (HRPSoC) condition is significantly improved by more than 224% from 8142 to 26,425 cycles. In comparison to the conventional carbon additions like the activated carbon and acetylene black, the 3D-RGO also exhibits the highest initial discharge capacity, the best rate capabilities and the longest HRPSoC cycling life. Finally, we propose a possible mechanism for 3D-RGO to suppress lead-acid battery sulfation, where the abundant pore structure and excellent conductivity of 3D-RGO may have a synergistic effect on facilitating the charge and discharge process of negative plate. [ABSTRACT FROM AUTHOR]

All-solid-state lithium-ion batteries (ASSLIBs) are promising candidates for next-generation electric vehicle batteries. The contact interface between the active material (AM) and solid electrolyte (SE) is an important factor that affects the performance of ASSLIB. Composite particles, which are SE-coated AM particles, can form electrodes with large AM-SE contact interfaces. However, they can decrease in cell capacity because of the SE coating layer with electrical non-conductance. This study designed composite particles with conductive additives (CAs) using dry-coating. Acetylene black (AB) and vapor-grown carbon fiber (VGCF) were used as typical CAs, and the composite particles with these CAs were compared with those without CAs and simple mixture. Although the addition of CAs improved the cell capacity and decreased internal resistance, the type of CA significantly affected the rate performance. Because the VGCFs were barely incorporated into the SE coating layer, the incorporation of VGCFs did not improve the rate performance. However, the ABs were effectively incorporated into SE coating layer, resulting in the best rate performance in this study. This difference was due to the ease of supplying electrons to the AM particles. Therefore, AB was suitable for the CA of the composite particles to improve the performance of the ASSLIB. [Display omitted] • Preparation and characterization of composite particles with conductive additives. • VGCF more likely to be placed on the surface of the composite particles. • Acetylene black more likely to be incorporated into the SE coating layer. • Composite particles with acetylene black showed a higher battery performance. • Ease of supplying electrons to the active material affects the rate performance. [ABSTRACT FROM AUTHOR]

Herein, we introduce a multifunctional materials dry coating strategy on LiNi 0.8 Mn 0.1 Co 0.1 O 2 (NMC811) at 1 wt% with a thickness of ca. 100 nm. The materials included high chemical stable Al 2 O 3 (0.33 wt%) to reduce parasitic reactions, high electrical carbon black (0.33 wt%) to reduce internal charge transfer resistance, and high ionic conductive Li 7 La 3 Zr 2 O 12 (0.33 wt%) to enhance Li+ diffusion. The scalable dry coating mechanofusion used can also generate a smooth surface of spherical NMC811 particles enhancing its stability. With an exceptional property of mixed multi-functional materials, the cell of encapsulated NMC811 can perform up to 1000 cycles with 80% capacity retention. Whilst the pristine NMC811 cell can maintain only 39%. The coated NMC811 provides a two-fold specific capacity at a high C-rate (2.0C) compared to the pristine one. Moreover, it also offers excellent safety based on the UN38.3 standard at 18650 cylindrical cells. This multifunctional coating concept may lead to the further development of high-performance Li-ion batteries. [Display omitted] • Reducing intrinsic drawbacks of NMC811with a multifunctional materials coating. • Carbon black-Al 2 O 3 – Li 7 La 3 Zr 2 O 12- NMC811 strong bond at the interface. • Carbon black can reduce internal resistance of NMC811 Li-ion batteries. • Al 2 O 3 can reduce parasitic reactions of NMC811. • Li 7 La 3 Zr 2 O 12 can enhance Li-ion diffusion. [ABSTRACT FROM AUTHOR]

In this paper, graphite granule composite electrodes are prepared for microbial fuel cells (MFCs) by coating commercial graphite granules with the mixture of quaternary DABCO polysulfone or Nafion ion exchange polymer and carbon black. The results of electrochemical impedance spectroscopy (EIS) suggest that the addition of carbon black could significantly improve the electrical conductivity of graphite granule anodes. When phosphate buffer solution (PBS) is replaced by NaCl solution, the current densities of the pristine anode, 0.08 g Nafion coated anode and 0.16 g QDPSU coated anode decrease by 52.6%, 20.6% and 10.3% at −0.2 V (vs. Ag/AgCl), respectively. The solution resistance of ion exchange polymer coated anodes is more stable in comparison with that of pristine anode. After 40 operational days, the performance drop of 0.16 g QDPSU coated anode when switching the solution from PBS to NaCl is still smaller than that of pristine anode. However, 0.08 g Nafion coated anode shows the similar performance in NaCl solution to the pristine anode after long term operation. This study reveals that QDPSU anion exchange polymer is more suitable for the anode modification. The QDPSU coated anode promises a great potential for three-dimensional anode based MFCs to treat domestic wastewater. [ABSTRACT FROM AUTHOR]

To investigate geometric and electrochemical characteristics of Li ion battery electrode with different packing densities, lithium cobalt oxide (LiCoO 2 ) cathode electrodes were fabricated from a 94:3:3 (wt%) mixture of LiCoO 2 , polymeric binder, and super-P carbon black and calendered to different densities. A synchrotron X-ray nano-computed tomography system with a spatial resolution of 58.2 nm at the Advanced Photon Source of the Argonne National Laboratory was employed to obtain three dimensional morphology data of the electrodes. The morphology data were quantitatively analyzed to characterize their geometric properties, such as porosity, tortuosity, specific surface area, and pore size distribution. The geometric and electrochemical analysis reveal that high packing density electrodes have smaller average pore size and narrower pore size distribution, which improves the electrical contact between carbon-binder matrix and LiCoO 2 particles. The better contact improves the capacity and rate capability by reducing the possibility of electrically isolated LiCoO 2 particles and increasing the electrochemically active area. The results show that increase of packing density results in higher tortuosity, but electrochemically active area is more crucial to cell performance than tortuosity at up to 3.6 g/cm 3 packing density and 4 C rate. [ABSTRACT FROM AUTHOR]

Due to its high theoretical capacity, silicon is a promising active material candidate for the negative electrode of lithium ion batteries. One way to reduce the severe degradation of silicon during charge/discharge cycling, is to use blends of different active materials and a well-balanced ratio of active and inactive materials. To ensure high-energy densities while still maintaining good electronic conductivity and ionic mobility, the necessity of nano-scale conductive carbons within a graphite/silicon composite was evaluated in this study. In particular, the correlation of silicon particle size and the presence of conductive additive was studied in electrodes, predominantly consisting of graphite (15 wt% silicon). Carbon black as conductive additive has a high contact surface area, which can enhance the electronic conductivity within the electrode and thus the rate capability, however, it can also propagate parasitic side reactions. It was determined that composite electrodes containing micron-sized silicon particles depend on the addition of conductive additives with regard to electrochemical performance. Due to high contact area and small transport distances, electrodes based on nano-sized silicon showed comparable capacity retention and a higher specific discharge capacity. Omitting conductive particles from these composite electrodes allowed lower binder amounts, while maintaining a good mechanical electrode integrity. [Display omitted] • Optimization of C/Si-based composite electrode formulation. • Impact of different Si particle sizes varying from nano-to micro-scale. • Evaluation of the necessity of conductive additives in C/Si-based electrodes. • Reduction of inactive material content to maximize energy density. [ABSTRACT FROM AUTHOR]

Electrode processing and performance strongly depend on the active material. Maximizing the active material content of positive composite electrodes enables low cost and high energy density. However, this maximization cannot reach 100%, as composite electrodes additionally consist of binder to provide mechanical integrity and conductive additive to enhance electronic conductivity, which in combination create a flexible porous microstructure for appropriate electron and lithium transport. In this study, the influence of three positive active material classes, layered oxide LiNi 0.6 Mn 0.2 Co 0.2 O 2 , spinel-type LiMn 2 O 4 and olivine-type carbon-coated LiFePO 4 , were investigated regarding the optimum amount of polyvinylidene difluoride as binder and carbon black as conductive additive to achieve high mechanical stability as well as high electronic and ionic conductivity within composite electrodes. Formulation optimization was conducted and compared to a reference electrode formulation with regard to physical, mechanical, electronic and electrochemical properties. In a first step, the binder amount was optimized for each active material class by varying the ratio of binder content to surface area of the solid electrode components. In a second step, the critical conductive additive content was determined. Overall, this strategy allows to decipher material class dependent optimized electrode formulations for high energy density composite electrodes with maximized active material content. [Display omitted] • Strategy to develop material class dependent electrode formulations. • Active material particle surface and size affects binder and conductive additive amount. • Carbon-coated LiFePO 4 based composite electrodes show a high SOH with low conductive additive content. [ABSTRACT FROM AUTHOR]

The use of carbon materials having high crystallinity for the electrocatalyst is promising approach to improve durability of the polymer electrolyte membrane fuel cells (PEMFC) due to their excellent electrochemical stability. Polymer-coating on the surface of the carbon materials has been proposed as a unique method to deposit Pt nanoparticles homogeneously on such carbon materials. In this study, effect of the polymer-coating for the stability of Pt nanoparticle upon durability tests of the PEMFC is investigated. Pt nanoparticles deposited on the polybenzimidazole (PBI)-coated acetylene black (AB) is prepared and is used as an electrocatalyst in membrane-electrode-assembly (MEA). Accelerated durability tests (ADT) of MEA between 0.6 and 1.0 V are carried out using H 2 and N 2 in anode and cathode, respectively, and it is found that MEA employing PBI-coated AB shows only 8% decrease in the maximum power density, while MEA containing non-coated AB shows 34% decrease after the ADT. Structural analysis of the electrocatalysts after the ADT reveals that the PBI anchors both Pt nanoparticle and ionomer upon ADT and maintains their interfacial structure. We conclude that the polymer-coating method is promising both for the improvement of the durability and the activity of the PEMFC. [Display omitted] • Polymer coating on carbon support improves PEMFC durability. • Gas transport resistance is largely decreased by polymer coating. • Coated polymer prevents Pt migration and dissolution upon durability test. • Coated polymer prevents ionomer dissolution upon durability test. [ABSTRACT FROM AUTHOR]

Many studies have been recently conducted on Ni-rich cathodes to increase cell capacity. The improvement of cell capacity is reaching its limit by increasing Ni content of a cathode material. In addition, increasing Ni content of a cathode material is unsafe due to gas evolution. Thus, research on Ni-rich cathode should proceed in parallel with the development of cell design, i.e., thickening electrode. However, during a calendering process, upper layer particles with low mechanical strength can be fractured, which is a problem with a thick electrode. To solve this issue, electrodes were designed using single crystalline lithium nickel cobalt manganese oxides (NCM) of high mechanical strength together with existing polycrystalline NCM in the present study. Four types of electrodes were tested to determine the best design for the electrode. Among them, double layer of upper layer with single crystalline and lower layer with polycrystalline (DB) completely prevented particle fracturing in the upper layer while maintaining sufficient tortuosity within the electrode. The reaction within the electrode was much more uniform than in other samples. As a result, DB had higher capacity of 34.6 mAh g−1 than the pristine after 40 cycles and a higher capacity of 50.5 mAh g−1 at 2C. • Particles on the upper layer of electrode can be fractured by the pressing force. • The carbon black and PVDF of the upper layer can be agglomerated. • The upper layer of the DB was entirely made of SC, there was no upper layer crack. • The DB enabled a uniform reaction within the electrode without upper layer crack. [ABSTRACT FROM AUTHOR]

Developing efficient electrocatalysts for oxygen reduction reaction (ORR) is fundamental to bring the Li–O 2 technology closer to practical applications. However, the majority of studied catalysts for this application are either precious metals or cobalt based, which represents an obstacle for a larger scale development, both from an economical and a political point of view. In this work a simple, fully sustainable, and economic synthesis process is used to in situ nucleate SnO 2 nanoparticles on the surface of commercial carbon black (C45) by taking advantage of its numerous nucleation sites to deposit and chemically anchor SnO 2 nanoparticles. Such synthesis can easily be carried out through wet impregnation, without any acid treatment or high temperature process. The obtained composite material shows an optimal ORR activity, which is confirmed in Li–O 2 cells. Indeed, compared to pure C45 air-cathodes, the composite cathodes lead to the formation of much more reversible film-like discharge products, allowing for reduced overvoltage and therefore improved cycling performances both at the high current density of 0.5 mA cm−2 with more than 70 cycles and in prolonged discharge/charge conditions with over 1250 h of operation at the fixed capacity of 2.5 mAh cm−2. [Display omitted] • ORR catalyst composed of SnO 2 nanoparticles grafted on the surface of carbon black. • Composite catalyst obtained through a simple and sustainable process. • Optimal ORR activity with a final reduction mechanism following 4 electrons pathway. • Formation of much more reversible film-like discharge products. • Reduced overvoltage and improved cycling performances at high current density. [ABSTRACT FROM AUTHOR]

The electrospinning method is used to fabricate the microporous layers (MPL). The hydrophobic and hydrophilic electrospun MPLs (E-MPLs) are realized by using acetylene black and pigmented carbon black in the electrospinning ink, respectively. Scanning electron microscope shows that the E-MPLs have three-dimensional inter-connected pore structure formed by disordered nanofibers. Mercury intrusion porosimetry results indicate that the E-MPLs have larger porosity (more than 85%) and wider pore size distribution (0.8–4 μm) compared with the commercial MPL (from SGL 29BC). Hydrophobic E-MPL exhibits lower mass transport resistance at 100% relative humidity (RH) due to its larger pore size and better water drainage capability, while the hydrophilic E-MPL shows lower ohmic resistance at 40% RH due to its higher water retention capability. Fuel cell with a double-layer E-MPL, an integrated MPL containing a hydrophilic layer and a hydrophobic layer, is found to perform well under wider RH range. The fuel cell with double-layer E-MPL is found to have a better dynamic response to a current step, in that it has lower amplitude of voltage undershoot and overshoot, and reaches a steady state more quickly. • Electrospun microporous layers with different wettability were fabricated. • The fuel cells with E-MPLs showed lower mass transport resistance. • The double-layer E-MPL performed well in wide relative humidity range. • The double-layer E-MPL had better dynamic response at high humidity. [ABSTRACT FROM AUTHOR]

We focus on Pt degradation occurring during fuel cell vehicle (FCV) combined drive cycles involving load and open circuit voltage (OCV) just after startup and during idling. Load cycle durability is evaluated as a function of OCV/load holding time, load rate and relative humidity (RH) with a graphitized carbon black-supported platinum catalyst (Pt/GCB) in the cathode. The degradation of Pt/GCB is suppressed for shorter OCV holding times, lower load rates and lower RH. Scanning ion microscopy (SIM) images of membrane cross-sections indicate that the amount of Pt deposited in the membrane decreases during drive cycles involving load with short OCV holding times. Investigations of the Pt distribution in the cathode catalyst layer (CL) by using scanning TEM-EDX show that the dissolution of Pt is suppressed on the membrane side in the CL. The Pt dissolution is accelerated by the high Pt oxidation due to the long OCV holding time. A load cycle with both long OCV holding time and low load inhibits the Pt 2+ migration into the membrane but accelerates the Pt particle growth due to electrochemical Ostwald ripening; meanwhile, a load cycle with long OCV holding time at lower RH prevents both the Pt dissolution and particle growth. [ABSTRACT FROM AUTHOR]

Suspension plasma spray deposition is utilized to fabricate solid oxide fuel cell cathodes with minimal material decomposition. Adding carbon black as a pore former to the feedstock suspension results in smoother and more porous coatings, but over the range of carbon black concentrations studied, has little impact on the overall symmetrical cell performance. The cathode made with a suspension containing 25 wt% carbon has the highest deposition efficiency and a polarization resistance of 0.062 Ωcm 2 at 744 °C. This cathode is tested for 500 h, and it is observed that adding an SDC interlayer between the YSZ electrolyte and the cathode(s) and/or coating the metal substrate with lanthanum chromite decrease the rate of performance degradation. [ABSTRACT FROM AUTHOR]

A composite film based on carbon black nanoparticles and sulfonated-poly(thiophene-3-[2-(2-methoxyethoxy)ethoxy]-2,5-diyl) (CB-NPs/s-PT) is formed on a flexible titanium foil for the use as the electro-catalytic counter electrode (CE) of dye-sensitized solar cells (DSSCs). The CB-NPs provide the large amount of electro-catalytic active sites for the composite film, and the s-PT polymer serves as a conductive binder to enhance the inter-particle linkage among CB-NPs and to improve the adhesion between the composite film and the flexible substrate. The flexible CB-NPs/s-PT composite film is designed to possess good electro-catalytic ability for I − / I 3 − redox couple by providing large active sites and rapid reduction kinetic rate constant of I 3 − . The cell with a CB-NPs/s-PT CE exhibits a good cell efficiency ( η ) of 9.02 ± 0.01% at 100 mW cm −2 , while the cell with a platinum CE shows an η of only 8.36 ± 0.02% under the same conditions. At weak light illuminations (20–80 mW cm −2 ), a DSSC with CB-NPs/s-PT CE still exhibits η 's of 7.20 ± 0.04–9.08 ± 0.02%. The low-cost CB-NPs/s-PT CE not only renders high cell efficiency to its DSSC but also shows a great potential to replace the expensive platinum; moreover it is suitable for large-scale production or for indoor applications. [ABSTRACT FROM AUTHOR]

Manganese oxides (MnO x ) in α-, β-, γ-, δ-MnO 2 phases, Mn 3 O 4 , Mn 2 O 3 , and MnOOH are synthesized for systematically comparing their electrocatalytic activity of the oxygen reduction reaction (ORR) in the Zn–air battery application. The optimal MnO x /XC-72 mass ratio for the ORR is equal to 1 and the oxide crystalline structure effect on the ORR is compared. The order of composites with respect to decreasing the ORR activity is: α-MnO 2 /XC-72 > γ-MnO 2 /XC-72 > β-MnO 2 /XC-72 > δ-MnO 2 /XC-72 > Mn 2 O 3 /XC-72 > Mn 3 O 4 /XC-72 > MnOOH/XC-72. The textural properties of MnO x are investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), N 2 adsorption/desorption isotherms with Brunauer–Emmett–Teller (BET) analysis, X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Electrochemical studies include linear sweep voltammetry (LSV), rotating ring-disk electrode (RRDE) voltammetry, and the full-cell discharge test. The discharge peak power density of Zn–air batteries varies from 61.5 mW cm −2 (α-MnO 2 /XC-72) to 47.1 mW cm −2 (Mn 3 O 4 /XC-72). The maximum peak power density is 102 mW cm −2 for the Zn–air battery with an air cathode containing α-MnO 2 /XC-72 under an oxygen atmosphere when the carbon paper is 10AA. The specific capacity of all full-cell tests is higher than 750 mAh g −1 at all discharge current densities. [ABSTRACT FROM AUTHOR]

PdAg and PdAu alloy nanoparticle catalysts for the glycerol oxidation reaction (GOR) were prepared at room temperature by a wet method. The molar ratio of the precursors controlled the bulk composition of the PdAg and PdAu alloys, and their surface composition was Ag-enriched and Pd-enriched, respectively. On PdAg-loaded carbon black (PdAg/CB) electrodes, the onset potential of GOR was 0.10–0.15 V more negative than on the Pd/CB electrode due to the electronic effect. The ratio of GOR peak current densities in the backward and forward sweeps of CVs ( i b / i f ) was smaller because of the improved tolerance to the poisoning species. The ratio of the GOR current density at 60 and 5 min ( i 60 / i 5 ) for the PdAg/CB electrodes was higher for more negative potentials than the Pd/CB electrode. In contrast, the PdAu-loaded CB (PdAu/CB) electrodes had an onset potential of GOR similar to the Pd/CB electrode and a higher GOR peak current density owing to the bi-functional effect. However, the i b / i f ratio was higher for PdAu/CB because of the increase in i b as the Pd surface was recovered, and the i 60 / i 5 ratio was higher for more positive potentials, similar to the Pd/CB electrode. [ABSTRACT FROM AUTHOR]

A series of well-dispersed bimetallic Pd@Pt nanodendrites uniformly supported on XC-72 carbon black are fabricated by using different capping agents. These capping agents are essential for the branched morphology control. However, the surfactant adsorbed on the nanodendrites surface blocks the access of reactant molecules to the active surface sites, and the catalytic activities of these bimetallic nanodendrites are significantly restricted. Herein, a facile reflux procedure to effectively remove the capping agent molecules without significantly affecting their sizes is reported for activating supported nanocatalysts. More significantly, the structure and morphology of the nanodendrites can also be retained, enhancing the numbers of active surface sites, catalytic activity and stability toward methanol and ethanol electro-oxidation reactions. The as-obtained hot water reflux-treated Pd@Pt/C catalyst manifests superior catalytic activity and stability both in terms of surface and mass specific activities, as compared to the untreated catalysts and the commercial Pt/C and Pd/C catalysts. We anticipate that this effective and facile removal method has more general applicability to highly active nanocatalysts prepared with various surfactants, and should lead to improvements in environmental protection and energy production. [ABSTRACT FROM AUTHOR]

An issue with conventional non-aqueous Li–O 2 battery cathodes that are formed by spraying/brushing/casting/coating carbon black slurries is a lack of sufficiently large pores, vulnerable to clogging by solid discharge products, and hence resulting in a low capacity. In this work, we report a novel cathode structure formed by screen-printing method. This deposition method allows the creation of evenly distributed large pores (∼10 μm). As compared with the cathode formed by slurry-coating method, the cathode formed by the present method increases the battery's capacity by two times. The cyclability is also seen a significant improvement. The improved performance may be attributed to large pores that give more appropriate distributions of discharge products and hence facilitate the transportation of oxygen during cycling. [ABSTRACT FROM AUTHOR]

We demonstrate the possibility of direct power generation from waste coffee grounds (WCG) via high-temperature carbon fuel cell technology. At 900 °C, the WCG-powered fuel cell exhibits a maximum power density that is twice than carbon black. Our results suggest that the heteroatoms and hydrogen contained in WCG are crucial in providing good cell performance due to its in-situ gasification, without any need for pre-reforming. As a first report on the use of coffee as a carbon-neutral fuel, this study shows the potential of waste biomass (e.g. WCG) in sustainable electricity generation in fuel cells. [ABSTRACT FROM AUTHOR]

The lithium–sulfur system is one of the most promising next generation battery systems, as elemental sulfur is cheap, abundant and has a high theoretical specific capacity. Although much research is conducted on complex sulfur/carbon composites and architectures, it is difficult to compare the performance of the cathodes to one another. Factors, such as different electrolyte composition and cell components strongly affect the cyclability of the battery. Here, we show the importance of optimizing “standard” conditions to allow for fair performance comparison of different carbon blacks. Our optimal electrolyte-to-sulfur ratio is 11 μL mg sulfur −1 and high concentrations of LiNO 3 (>0.6 M) are needed because nitrate is consumed continuously during cycling. Utilizing these standard conditions, we tested the cycling behavior of four types of cathodes with individual carbon blacks having different specific surface areas, namely Printex-A, Super C65, Printex XE-2 and Ketjenblack EC-600JD. Both the specific capacity and polysulfide adsorption capability clearly correlate with the surface area of the carbon being used. High specific capacities (>1000 mAh g sulfur −1 at C/5) are achieved with high surface area carbons. We also demonstrate that a simple cathode using Ketjenblack EC-600JD as the conductive matrix material can well compete with those having complex architectures or additives. [ABSTRACT FROM AUTHOR]

Organic/polymer cathodes have attracted increased attention due to their versatile structures, low cost, facile synthesis, and environmental friendliness. However, the high viscosity of polymers makes achieving manipulable morphology in organic/polymer:conductive agent composites a significant challenge. In response, we report herein a new electrospinning strategy for controlling the micro-nano morphologies of a p-type high-voltage polymer, poly(N -vinyl carbazole) (PVK), with carbon black Super P (SP). The PVK-based fiber cathode (PSP50) made through this strategy possesses a fine 3D nanoporous structure, fast ion/electron transport properties, and ultrafast reaction kinetics. In comparison with PSP electrodes made by traditional methods, like dry-mixing (PSP-dm) and coating (PSP-co), PSP50 exhibits a high discharge capacity of 122 mAh g−1 at 50 mA g−1 with an average discharge voltage of 3.75 V, remarkable rate capability of 1 A g−1, and superior cycling stability with 73% capacity retention after 1000 cycles at 500 mA g−1. This study provides a new direction for regulating micro-nano morphologies of organic cathodes for high-performance lithium-organic batteries. [Display omitted] • A straightforward strategy for electrospinning organic electrodes is proposed. • Micro-nano morphology regulation of polymer cathodes is achieved. • PVK fiber cathode with excellent comprehensive performance is realized. [ABSTRACT FROM AUTHOR]

We report the first use of lithiated carboxylated nitrile butadiene rubber (XNBR-Li) as a functional binder for the sulfur cathode of lithium sulfur batteries (LSBs). XNBR-Li has strong adhesion to sulfur and carbon black particles, forming a uniformly dispersed and robust sulfur cathode structure. Furthermore, due to the presence of the -COOLi groups, XNBR-Li has shown a strong ability to trap lithium polysulfides (LPS), which greatly helps to suppress the shuttle effect of LPS in LSBs. The cyclic voltammetry and electrochemical impedance spectroscopy data indicate that the use of XNBR-Li as the binder can accelerate Li+ diffusion kinetics in the sulfur cathode. As a result, the XNBR-Li-based cathode delivers a high capacity of 1140 mAh g −1 at 0.2 C, high rate performance with a capacity of 729 mAh g−1 at a high rate of 2 C, and excellent long-term cycling stability with a slow capacity decay rate of 0.04% per cycle at 0.5 C over 500 cycles. [Display omitted] • XNBR is lithiated by lithium hydroxide used as a binder for the first time. • The lithiated XNBR shows a greatly improved lithium polysulfides trapping ability. • The lithiated XNBR accelerates Li + diffusion kinetics in the sulfur cathode. • The sulfur cathode with lithiated XNBR as binder displays excellent performance. [ABSTRACT FROM AUTHOR]

The porosity of anode polymer electrolyte membrane water electrolyzer catalyst layers (CLs) is usually low due to the use of an unsupported catalyst. By adding carbon to the Ir catalyst ink, which is then oxidized in-situ, the CL porosity can be increased from 58% to 77% while the number of CL cracks is decreased. The electrochemical surface area (ECSA) also increases from 21.5 to 28.3 m 2 /g. Cell performance improves substantially for cells with carbon at both low and high current densities. At 1.8 V, the current density increases from 3.16 to 3.70 A/cm 2 with increasing carbon content. Volcano-shaped cracks, observed in used CL without carbon, disappear with the addition of carbon. These cracks are hypothesized to be caused by high gas pressures within the CL, which are reduced due to improved mass transport. The degradation rate also improves from 626 to 522 μ V/h with carbon addition. Anode electrodes with and without carbon are also fabricated with a low electrically conductive IrO x catalyst. Results also show increased porosity, ECSA, and performance at low current density, however no improvement was observed at high current density. • Carbon addition to Ir-based PEMWE electrode inks increases porosity and active area. • Carbon addition to electrode inks reduces cracks during fabrication and operation. • When carbon is added the current density at 1.8 V increases from 3.16 to 3.70 A/cm 2. • The impact of carbon content is dependent on the type of catalyst used. [ABSTRACT FROM AUTHOR]

Carbon nanotubes (CNT) based nanoporous layer contacting the catalyst layer in polymer electrolyte membrane fuel cells (PEMFCs) is investigated. Nanoporous CNT-5, CNT-15, and CNT-40 sheets are prepared via direct spinning method with thicknesses is 5, 15, and 40 μm, respectively. The ethanol-derived CNT-5 possess sparse pore networks, whereas CNT-15 and CNT-40 derived from acetone exhibit fine networks, and CNT-15 and CNT-40 differ only in thickness. The CNTs are employed as either standalone nanoporous layer or as an additional layer with carbon-black microporous layer (MPL). Scanning electron microscopy and sessile drop method are utilized for CNT characterization. Current-voltage polarization curve and electrochemical impedance spectroscopy are recorded for the PEMFC characterization. The best performance is obtained when CNT-15 is adopted as an additional nanoporous layer with MPL in the dry operation. The current densities at a cell voltage of 0.6 V are 0.454 and 0.743 A cm−2 in dry and wet operations, respectively, corresponding to an increase of 28.5% and 57.1%, respectively, compared to carbon-black MPL. Enhancements in water management and reaction kinetics lead to this performance increase. In particular, the enhanced water storage and expulsion are benefits differentiated from employing CNT as the single nanoporous layer. [Display omitted] ∙ CNT-based nanoporous layers were employed to GDL of PEMFC. ∙CNTs were fabricated via cost-effective direct spinning method. ∙Additional nanoporous layer (w/ MPL) increased current density by 57% (at 0.6 V). ∙Mitigated charge transfer and ohmic resistances led to performance enhancements. ∙The correlation between the quality of CNT and fuel cell performance was subpar. [ABSTRACT FROM AUTHOR]

Conductive additives, like carbon black or graphite, are essential components of lithium ion batteries due to the limited electrical conductivity of most electrode materials. However, there is still a lack of knowledge about the optimized distribution of these materials within the electrode. A dry mixing process is used in order to prepare a conductive coating by depositing carbon black on the surface of Li(Ni 1/3 Mn 1/3 Co 1/3 )O 2 (NMC) cathode particles. It is demonstrated that this – from a theoretically point of view – favorable distribution does not allow the preparation of working electrodes without taking into account the role of the binder. After adding an organic binder to the slurry, the polymer deposits on top of the carbon shell during drying and inhibits the conductive contact between the particles. This can be avoided by a fraction of distributed carbon particles which are associated with the binder phase providing conductive paths through the isolating organic material. It is shown that carbon black and graphite are principally fulfilling this task, but both materials are leading to varying processing behavior and electrode properties. [ABSTRACT FROM AUTHOR]

The performance of practical-sized membrane-electrode assemblies (MEAs) using titanium nitride-supported platinum (Pt/TiN) as the cathode catalysts was evaluated with the use of a practical single cell designed for microscale combined heat and power (CHP) applications. The performance can be controlled by adding acetylene black (AB), with the behavior being dominated by the percolation law. The electrical resistance of the MEAs drastically decreased for AB contents greater than 37 vol%. The Pt utilization percentage was close to 100% for Pt/TiN with percolated AB networks. It was also found that the percolated AB networks supplied effective gas transport pathways, which were not flooded by generated water, thus enhancing the oxygen mass transport. The practical-sized MEA using Pt/TiN + 47 vol% AB showed 1.5 times greater mass activity and a comparable performance under a practical operating condition for micro-CHP applications, compared with the MEA using a commercial graphitized carbon black-supported platinum catalyst. [ABSTRACT FROM AUTHOR]

Pd metal particles supported on a high surface area carbon black (Pd/CB) were covered with silica layers to improve the durability under severe cathode condition of proton exchange membrane fuel cells (PEMFCs). The performance and the durability of the silica-coated Pd/CB (SiO 2 /Pd/CB) were investigated by rotating disk electrode (RDE) in aqueous HClO 4 and single cell test of the membrane-electrode assemblies (MEAs). SiO 2 /Pd/CB showed excellent durability exceeding Pt/CB during potential cycle in single cell test as well as in RDE measurement while Pd/CB significantly degraded. Furthermore, the MEA using SiO 2 /Pd/CB as the cathode catalyst showed higher performance than that using Pd/CB even in the initial state. The catalytic activity of SiO 2 /Pd/CB was higher than that of Pd/CB, and the drop of the cell performances due to the inhibition of electron conduction, proton conduction, and oxygen diffusion by the silica layer was not significant. It has been shown that the silica-coating is a very practical technique that can stabilize metal species originally unstable in the cathode condition of PEMFCs without a decrease in the cell performance. [ABSTRACT FROM AUTHOR]

Here we report a facile two-step method to synthesize high-performance palladium/graphitic carbon nitride/carbon black (Pd/g-C 3 N 4 /carbon black) hybrids for electrooxidizing formic acid and methanol. The coating of g-C 3 N 4 on carbon black surface is realized by a low-temperature heating treatment, followed by the uniform deposition of palladium nanoparticles (Pd NPs) via a wet chemistry route. Owning to the significant synergistic effects of the individual components, the preferred Pd/g-C 3 N 4 /carbon black electrocatalyst exhibits exceptional forward peak current densities as high as 2155 and 1720 mA mg −1 Pd for formic acid oxidation in acid media and methanol oxidation in alkaline media, respectively, far outperforming the commercial Pd-C catalyst. The catalyst also shows reliable stability, demonstrating that the newly-designed hybrids have great promise in constructing high-performance portable fuel cell systems. [ABSTRACT FROM AUTHOR]

This study adopts a modified atomic layer deposition (ALD) process to prepare size-controlled Pt nanoparticles on the surface of carbon black, showing superior catalytic activity toward ethanol oxidation. Two types of ALD precursors, (methylcyclopentadienyl) trimethyl platinum (MeCpPtMe 3 ) and oxygen (O 2 ), were used to grow Pt deposits at 250 °C. For 30 ALD cycles, the pulse period of MeCpPtMe 3 serves as a key factor in controlling the particle size and the weight loading of Pt deposits. The Pt growth rates over the carbon support can be attributed to the surface coverage of Pt–O* sites, diffusion rate of MeCpPtMe 3 , and lateral interaction between each active site. Since the MeCpPtMe 3 dose strongly affects the Pt particle size and the deposit density, the growth of ALD–Pt can be assumed as being diffusion-limited. Because of the surface-catalyzed reaction steps, the small-sized ALD-Pt catalysts offer better catalytic activity, CO tolerance, and long-term stability as compared with the large-sized ones. On the basis of the results, the modified ALD technique exhibits a great potential for tuning the Pt particle size and weight loading onto the carbon support for fuel cell application. [ABSTRACT FROM AUTHOR]

A novel method is developed to increase the resistance to electrochemical carbon corrosion using a self-assembled organosilane coating of dodecyltrichlorosilane (DTS) on carbon black (CB). This process successfully creates a hydrophobic coating on the hydrophilic surface of carbon black without poisoning Pt nanoparticles. The hydrophobic DTS coating improves the performance of CB in fuel cells by enhancing the mass transfer rate. Following carbon corrosion tests, on-line mass spectrometry shows that this DTS coating improves the electrochemical carbon corrosion resistance of CB by increasing the contact resistance of water, which is necessary for electrochemical carbon corrosion. Thus, this DTS coating is a very effective means to improve the performance and durability of fuel cells. [ABSTRACT FROM AUTHOR]

Biochar, also known as black carbon, is a byproduct of biomass pyrolysis. As a low-cost, environmental-friendly material, biochar has the potential to replace more expensive synthesized carbon nanomaterials (e.g. carbon nanotubes) for use in future supercapacitors. To achieve high capacitance, biochar requires proper activation. A conventional approach involves mixing biochar with a strong base and baking at a high temperature. However, this process is time consuming and energy inefficient (requiring temperatures >900 °C). This work demonstrates a low-temperature (<150 °C) plasma treatment that efficiently activates a yellow pine biochar. Particularly, the effects of oxygen plasma on the biochar microstructure and supercapacitor characteristics are studied. Significant enhancement of the capacitance is achieved: 171.4 F g −1 for a 5-min oxygen plasma activation, in comparison to 99.5 F g −1 for a conventional chemical activation and 60.4 F g −1 for untreated biochar. This enhancement of the charge storage capacity is attributed to the creation of a broad distribution in pore size and a larger surface area. The plasma activation mechanisms in terms of the evolution of the biochar surface and microstructure are further discussed. [ABSTRACT FROM AUTHOR]

To improve the electrochemical performance of Na 2 Li 2 Ti 6 O 14 , carbon black (CB), graphene (GN) and carbon nanotube (CNT) are introduced to fabricate high conductive Na 2 Li 2 Ti 6 O 14 /CB, Na 2 Li 2 Ti 6 O 14 /GN, Na 2 Li 2 Ti 6 O 14 /CNT and Na 2 Li 2 Ti 6 O 14 /CB/GN/CNT by a solid state method. It can be found that only CNT forms a complete three-dimensional conductive network which embeds the randomly distributed Na 2 Li 2 Ti 6 O 14 particles, leading to an improvement of electronic conductivity. The results of cyclic voltammetry, electrochemical impedance spectroscopy and charge–discharge tests reveal that Na 2 Li 2 Ti 6 O 14 /CNT obtains the lowest redox polarization and the highest peak current among all the five samples. As a result, Na 2 Li 2 Ti 6 O 14 /CNT shows the best cycling and rate performances among all the five samples. It reveals a charge capacity of 111.4 mAh g −1 at 100 mA g −1 , 110 mAh g −1 at 200 mA g −1 , 103.9 mAh g −1 at 300 mA g −1 and 98.9 mAh g −1 at 400 mA g −1 . For comparison, bare Na 2 Li 2 Ti 6 O 14 only displays a charge capacity of 89.9 mAh g −1 at 100 mA g −1 , 79.7 mAh g −1 at 200 mA g −1 , 73.7 mAh g −1 at 300 mA g −1 and 69.4 mAh g −1 at 400 mA g −1 . It indicates that the introduction of CNT is more effective to improve the performance of Na 2 Li 2 Ti 6 O 14 than CB, GN and CB/GN/CNT. [ABSTRACT FROM AUTHOR]

Reduced graphene oxide/carbon black (rGO/CB) hybrid films with different carbon black (CB) contents are prepared by a simple vacuum filtration method. The CB particles evenly distribute between the graphene layers, not only preventing the compact restack of rGO sheets but also providing electrical contact between the base planes of rGO sheets. As expected, the as-prepared rGO/CB hybrid film shows enhanced rate capability when compared with rGO film. Furthermore, a solid-state flexible supercapacitor has been constructed with the optimized rGO/CB hybrid film by using polyvinyl alcohol (PVA)/H 2 SO 4 gel as electrolyte and Au coated PET film as current collector and mechanical support. The solid-state flexible supercapacitor shows a specific capacitance of 112 F g −1 at a scan rate of 5 mV s −1 , and excellent rate performance with a specific capacitance of 79.6 F g −1 at a high scan rate of 1 V s −1 . Moreover, the flexible solid-state supercapacitor exhibits good cycling stability with capacitance retention of 94% after 3000 cycles in normal state plus 2000 cycles in bent state. [ABSTRACT FROM AUTHOR]