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A fuel cell involving CO 2 /H 2 is an appealing energy system to convert CO 2 into synthetic fuels as well as to generate electricity using only waste heat. However, overcoming the inherent activation barrier of CO 2 to improve the CO 2 conversion rate in CO 2 /H 2 fuel cell is still challenging. Herein, we report a synergistic electron-donor and proton-repulsion group composed of Pt-N 3 -S-C sites to simultaneously modulate the electronic structure and CO 2 -protonation ability of Ru nanoclusters (Ru NC) in Ru NC /Pt-N 3 -S-C catalyst. Experiments combined with theoretical calculations indicate that Pt-N 3 -S sites not only function as electron donors to Ru nanoclusters to cooperatively induce the orbital hybridization of Ru 3d and the antibonding orbitals of CO 2 , affording the dissociation of C O bonds in CO 2 , but also as electronic structure "modulator" to create new active sites on the surface of Ru NC to effectively activate molecular CO 2. More importantly, an internal polarization field between Pt-N 3 -S-C and Ru NC additionally makes single atom Pt sites repel protons while Ru atoms serve as proton capturers via hydrogen spillover effect, resulting in accelerated protonation of CO 2. Consequently, the catalyst exhibits highly improved catalytic activities for CO 2 reduction with a conversion rate of 559.1 μmol g cat −1 h−1. This approach helps with fine tuning the electronic structures and catalytic CO 2 protonation ability of catalysts for thermal-coupled electrocatalysis. [Display omitted] • A CO 2 /H 2 fuel cell to reduce CO 2 and generate electricity was developed. • Pt-N 3 -S sites can modulate the electronic structure and CO 2 -protonation ability of Ru. • The featured catalysts exhibited excellent catalytic performance for CO 2 reduction. • The catalytic mechanism of catalyst was investigated and revealed in depth. [ABSTRACT FROM AUTHOR]

Abstract Energy consumption continues to rise as society develops worldwide. Meanwhile, a lot of energy is wasted in the form of heat from various devices and systems. Here we report a new power generator, which works based on a difference in H+-ion concentration in a fuel cell structure and produces electricity by harvesting waste heat. The device works via the following three successive processes: H 2 is oxidized at anode to H+ ions, the H+ ions then penetrate through a phosphoric acid-treated polybenzimidazole (PBI-PA) membrane and finally the H+ ions get reduced to H 2 at cathode with electrons coming through external circuit from the anode. This system generates electricity at a current density of 21 mA cm−2 and a power density of 1.03 mW cm−2 at 170 °C. The cell's thermoelectric conversion efficiency at 170 °C is 13.72%, which is higher than typical values reported for many common thermoelectric materials in low temperature regimes. This innovative approach may allow for efficient generation of electricity from waste heat. Graphical abstract fx1 Highlights • A new power generator based on fuel cell structure, H+-ion concentration difference, and waste heat is reported. • The cell takes H 2 at anode and ultimately releases it at cathode, with no overall consumption, except heat while producing electricity. • A high current density of 21 mA cm−2 and a power density of 1.03 mW cm−2 at 170 °C can be obtained. • Thermoelectric conversion efficiency of 13.72% at 170 °C and 3.38% at 50 °C can be achieved by the cell. • The thermoelectric conversion efficiency of the cell is much higher than those of thermoelectric materials-based cells. [ABSTRACT FROM AUTHOR]

Abstract Potassium-ion batteries (PIBs) have been receiving a great deal of attention owing to abundant and cost-effective potassium resources. However, the key issue is to explore suitable electrode materials for accommodating the large size K-ions reversibly. In this report, K 1.06 Mn 8 O 16 /CNT hybrids are systematically studied for the first time as bifunctional PIBs-electrodes, in which Mn-ions play as the redox center. As the cathode, it exhibits excellent electrochemical kinetics and reversibility, as well as highly structure stability. The cathode displays an unprecedented capacity of 309.4 mA h g−1 at 20 mA g−1 with the energy density of 733.3 Wh kg−1 and outstanding rate performance (187.1 mA h g−1 at 500 mA g−1). In addition, the high capacity of 636.6 mA h g−1 at 20 mA g−1, ultra-long cycling lifespan over 500 cycles and remarkable rate capability can also be acquired when the material was tested as the anode. The extraordinary electrochemical properties are ascribed to the well-developed conductive network and robust microstructure stability. Meanwhile, the symmetrical K-ions full cell exhibits high discharge capacity of 241.0 mA h g−1 at 100 mA g−1. This work reveals the K-ions storage mechanism in cryptomelane bifunctional electrodes in depth and the fundamental understanding help us open up a new direction for PIBs. Graphical abstract fx1 Highlights • K 1.06 Mn 8 O 16 /CNT nanohybrid was employed as bifunctional PIBs-electrodes for the first time. • The bifunctional electrodes exhibit excellent electrochemical performances benifited its unique 3D network architecture. • The K-ions storage mechanism for cathode is studied in depth. • The symmetrical K-ions full cell with high discharge capacity was confirmed based on bifunctional electrodes. [ABSTRACT FROM AUTHOR]

Abstract For the first time, a generalised enzyme-catalysed room temperature and atmospheric pressure method for synthesising metal carbonate hydroxides is shown. The enzyme urease was used to catalyse the hydrolysis of urea at room temperature and atmospheric pressure. Product CO 3 2- and OH- anions were separated from urease and used to precipitate low crystallinity metal carbonate hydroxides from solutions containing Ni2+, Co2+, Zn2+ and/or Cu2+ cations. Ni-Co carbonate hydroxides with different Ni2+/Co2+ molar ratios were evaluated as supercapacitor electrodes. An optimised Ni2+/Co2+ molar ratio of 3:1 yielded a specific capacitance of 1499 F g-1 @ 1 A g-1 current density. Combining this material with graphene oxide increased the specific capacitance to 1656 F g-1 @ 1 A g-1 current density. In turn, using this composite as the positive electrode in an asymmetric supercapacitor with activated carbon as the negative electrode yielded a high energy density of 45.8 Wh kg-1 at a power density of 899 W kg-1, and 70% capacitance retention after 10,000 cycles. Our enzyme-catalysed room temperature and atmospheric pressure method may be promising for industrial-scale production of nano-materials for energy conversion and storage. Graphical abstract fx1 Highlights • A generalised enzyme-catalysed room temperature and atmospheric pressure method for synthesising metal carbonate hydroxides was proposed. • All of metal carbonate hydroxides showed low crystallinity, which are different from those synthesised via hydrothermal method. • Ni-Co carbonate hydroxide with graphene oxide composite yielded a very high specific capacitance to 1656 F g-1 @ 1 A g-1 current density. • The asymmetric supercapacitor delivered high energy density of 45.8 Wh kg-1 at a power density of 899 W kg-1. [ABSTRACT FROM AUTHOR]

With the increasing application in antimicrobial products, silver nanoparticles (AgNP) are inevitably released into the terrestrial environment, and pose potential risks to invertebrates such as land snails Achatina fulica , which take up AgNP from food and water. Here we differentiate Ag uptake biodynamic between Ag forms (i.e., PVP-AgNP vs. AgNO 3 ) and between exposure pathways. Snails assimilated Ag efficiently from lettuce leaves pre-exposed to AgNP, with assimilation efficiencies (AEs) averaging 62–85% and food ingestion rates of 0.11 ± 0.03 g g −1 d −1 . Dietary Ag bioavailability was independent on Ag forms, as revealed by comparable AEs between AgNP and AgNO 3 . However, the uptake rate constant from water was much lower for AgNP relative to AgNO 3 (2 × 10 −4 vs. 0.12 L g −1 d −1 ). The elimination rate constants were 0.0093 ± 0.0037 d −1 for AgNP and 0.019 ± 0.0077 d −1 for AgNO 3 . Biodynamic modeling further showed that dietary exposure was the dominant uptake pathway for AgNP in most circumstances, while for AgNO 3 the relative importance of waterborne and dietary exposure depended on Ag concentrations in food and water. Our findings highlight the importance of dietary uptake of AgNP during bioaccumulation, which should be considered in the risk assessment of these nanoparticles. [ABSTRACT FROM AUTHOR]

Highlights: [•] Non-noxious mechanical stimulus elicits itch in skin inflamed by complete Freund's adjuvant. [•] Subcutaneous naltrexone reduces alloknesis score. [•] Premedication with kinin B1 receptor antagonist reduces alloknesis score. [•] Premedication with kinin B2 receptor antagonist increases alloknesis score. [Copyright &y& Elsevier]

Abstract: The effect of annealing time on the structure and electrochemical properties of La0.72Nd0.08Mg0.2Ni3.4Al0.1 hydrogen storage alloys was investigated. The alloys were annealed at 1173K for different time, and the results of Rietveld refinement for the XRD data showed that the alloys were composed of Gd2Co7-type, Ce2Ni7-type, Pr5Co19-type, PuNi3-type, LaNi5-type and MgCu4Sn-type phases. Lengthening annealing time obviously promoted the formation of Gd2Co7-type phase which possessed high hydrogen storage capacity, and the largest content of Gd2Co7-type phase was obtained when the alloys were annealed for 20h. The maximum discharge capacity increased from 365.0 (as-cast) to 389.6mAh/g (annealed for 20h), which was ascribed to Gd2Co7-type phase abundance increasing from 35% (as-cast) to a maximum (81.71%, annealed for 20h). Also, the discharge capacity retention over 180 cycles at charge/discharge current density of 300mA/g was remarkably heightened from 56.6% (as-cast) to 80.5% (annealed for 20h). In addition, annealing treatment at 1173K for 6h can enhance high rate discharge ability. [Copyright &y& Elsevier]

Abstract: A series of novel rectangular microscale carbon tubes with protuberant wall are prepared by polyaniline with hollow carbon nanospheres (HCNSs) as templates. By changing mass ratio of ammonium persulfate to HCNSs, the morphology and the tube dimension of those samples can be controlled. Chemical activation with KOH at 1123K results in a large specific surface area (SSA), ranging from 1680 to 2415m2 g−1, and big pore volumes, ranging from 1.274 to 1.550cm3 g−1. Electrochemical tests show that the special morphology effectively increases charge–discharge rate. The maximum capacitance reaches 230Fg−1 at a potential scan rate of 50mVs−1, and 50% of which even can be remained at a scan rate of 1000mVs−1. The electrochemical impedance tests show that the frequency exceeds 10Hz and even reaches up to 15Hz for the optimum sample corresponding to the 50% of the maximum capacitance, which is intensely higher than 1Hz for common porous carbon. [Copyright &y& Elsevier]

Abstract: The structure and electrochemical characteristics of (La1−x Dy x )0.8Mg0.2Ni3.4Al0.1 (x = 0–0.20) hydrogen storage alloys have been investigated. Dysprosium was adopted as a partial substitution element for lanthanum in order to improve electrochemical properties. The XRD, SEM and EDX results showed that the alloys were composed of (La, Mg)2Ni7, LaNi5 and (La, Mg)Ni2 phases. The introduction of Dy promoted the formation of (La, Mg)2Ni7 phase which possesses high hydrogen storage capacity, and controlling dysprosium content at 0.05 can obtain the maximum (La, Mg)2Ni7 phase abundance in the alloys. The maximum discharge capacity was heightened from 382.5 to 390.2 mAh/g, which was ascribed to (La, Mg)2Ni7 phase abundance increasing from 54.8% to a maximum (60.5%). Also, the biggest discharge capacity retention remained 82.7% after 100 cycles at discharge current density of 300 mA/g. [Copyright &y& Elsevier]

Abstract: A porous carbon made of polyaniline with different ferrocene loadings was prepared through carbonization and thermal chemistry activation with KOH. The ferrocene served as a pore-forming agent and a resource of iron nanoparticles. N2 adsorption/desorption measurements showed that the specific surface area and pore volume ranged from 2681 to 3246m2 g−1 and from 1.56 to 2.06cm3 g−1, respectively, with increasing ferrocene loadings. Similarly, hydrogen adsorption also increased from 5.3 to 6.2 wt% at 77K/5MPa and 0.6 wt% to 0.85 wt% at 293K/8MPa. Scanning electron microscopy, X-ray diffraction and energy dispersive X-ray analysis showed that iron nanoparticles were embedded in the carbon matrix or dispersed on the surface. The large specific surface area and big pore volume improved the original hydrogen adsorption heat up to 7.2kJmol−1 for the best sample. [Copyright &y& Elsevier]

Abstract: Porous materials, especially porous carbon materials, have the most potential as hydrogen adsorbents. In this research, a series of novel rectangular polyaniline tubes (RPTs) are synthesized using hollow carbon nanosphere (HCNS) templates. By changing mass ratios of ammonium persulfate to HCNSs, the sizes of RPTs can be controlled. Chemical activation with KOH gives rise to a large specific surface area (SSA), ranging from 1680 to 2415 m2 g−1, and big pore volumes that range from 1.274 to 1.550 cm3g−1. These observations demonstrate that activated rectangular polyaniline-based carbon tubes ARP-CTs are promising hydrogen adsorbents. Hydrogen uptake measurements show that the highest hydrogen adsorption reaches 5.2 wt% at 5 MPa/77 K and 0.62 wt% at 7.5 MPa/293 K respectively. Notably, the large pore volume can contribute 2.8 wt% to the total hydrogen storage which has approached 8.0 wt% at 5 MPa/77 K. [Copyright &y& Elsevier]

Abstract: With respect to first-principles calculations, the sandwich-type dinuclear organometallic compounds as (C5H5)2TM2 (M = Sc and Ti) can adsorb up to eight hydrogen molecules. The corresponding gravimetric hydrogen-storage capacity is 6.7 wt% for (C5H5)2Ti2 and 6.8 wt% for (C5H5)2Sc2. The multimetallocenes (e.g., CpTi3Cp and CpTi4Cp) complexes can further increase the H2 adsorption capacity to 8.7 wt% and 10.4 wt%, respectively. These sandwich-type organometallocenes proposed in this work are favorable for reversible adsorption and desorption of hydrogen under ambient conditions. These predictions will likely provide a new route for developing novel high-capacity hydrogen-storage materials. [Copyright &y& Elsevier]

Abstract: In recent years, large fluctuations have been reported for measurements of the hydrogen storage of carbon materials using a Sieverts apparatus. To investigate this problem, helium gas adsorption was selected for comparison with the adsorption of hydrogen, and the results show that hydrogen but not helium was adsorbed onto the wall of the sample cell at ambient temperature. The adsorption capacity of the sample cell at 77K is higher than that at ambient temperature. A series of adsorption tests was conducted with a LaNi5 alloy to prove the influence of the physisorption, and the results show that an increase in the hydrogen storage capacity was resulted in when sample loading decreases. After correction for this hydrogen physisorption, the capacity was restricted between 1.38 and 1.41wt.%. Multi-walled carbon nanotubes (MWCNTs), activated carbon (AC), single-walled carbon nanotubes (SWCNTs), graphite nanofibers (GNFs), and graphite oxide (GO) were also measured and corrected through this method. [Copyright &y& Elsevier]

Abstract Potassium-ion batteries (KIBs) are regarded as potentially promising large-scale energy storage (EES) systems due to the close redox potential to lithium, the rich reserve and low cost of potassium resources. Nevertheless, the larger ionic radius of K-ion makes cathode materials for KIBs be a difficult issue. Herein, we construct Mn-based layered oxide (K 0.32 MnO 2) microsphere, self-assembled by ultrathin nanosheets, as potential cathode electrode for nonaqueous KIBs, which delivers a reversible discharge capacity of 95.1 mAh·g−1 at 10 mA g−1. It is demonstrated that K 0.32 MnO 2 undergoes a simple solid solution reaction mechanism for K-ions deintercalation/intercalation during the initial charge-discharge process, which is not like complex multiple processes accompanied by phase transition for Mn-based layered oxide particles. Ex situ measurements reveal that K 0.32 MnO 2 nanosheets can provide outstanding morphology and structure stability, as well as fast electrochemical kinetics upon cycling, thus high rate capacity, improved cycling lifetime and voltage stability at low and high rates can be obtained. We also verify the practical feasibility of K-ion full cell with commercial super P carbon black anode. This novel work illuminates the electrochemical mechanism for K-ions storage in depth, which may push the study on layered oxide cathodes and accelerate the development of KIBs. Graphical abstract Image 1 Highlights • Mn-based layered oxide nanosheet was synthesized via a facile hydrothermal method. • Mn-based layered oxide nanosheet exhibits superior electrochemical performances. • The mechanism of K-ions extraction/insertion is analyzed in depth. • The improved properties are due to highly morphology and structural stability. [ABSTRACT FROM AUTHOR]

Artificial graphite is extensively used in power lithium-ion batteries for its exceptional stability and high-rate performance. However, the commercial high-temperature graphitization process is conducted at temperatures up to 3000 °C to enhance the degree of graphitization, resulting in significant electricity consumption and lengthy production cycles. This study aimed to lower graphitization temperatures and shorten times by using h-BN as a catalyst. Employing anthracite coal as the precursor and catalyzing with BN at 2800 °C for just 2 h, we achieved a remarkable graphitization degree of 93.3 %, compared to 83.5 % without BN. This indicates BN's effectiveness in accelerating graphite phase formation. Interestingly, the resultant graphite exhibited polyhedral morphology and incorporated boron doping. As edges increased, lithium-ion diffusion pathways and boron doping enhanced stability within the graphite layers, imparting high rate capability and robust cycle performance. The material delivered reversible specific capacities of 369.6 and 226 mA h g−1 at current densities of 0.1 and 3C, and maintained capacity retentions of 95 % and 92 % after 500 cycles at 0.5C and 1C. These results substantiate the potential for large-scale production of artificial graphite from anthracite coal using BN catalysis and underscore its promise as a superior anode material for lithium-ion batteries. [ABSTRACT FROM AUTHOR]

In fossil energy utilization processes, only about one-third of fuels is used effectively upon conversion, while the rest becomes waste heat. Therefore, making full use of waste heat is an effective way to save energy. Nowadays, the moderate-high temperature heat utilization systems continue to mature and develop. However, existing heat-to-electricity energy conversion technologies are not very efficient for utilization of low-grade waste heat. Herein, based on our previous finding in H+-ion concentration power generator, we design a cell stack structure in series to optimize and improve its thermal-to-electric performance with temperatures ranging from 50 °C to 170 °C. This experiment reveals that the thermal-to-electric conversion efficiency of 3-cell stack can reach up to 17.86%, which is more than twice as likely to a single-cell (8.39%). The electrochemical kinetic analysis and temperature distribution thermoanalysis results convince us that this tandem device is beneficial to the development for low-level heat recovery. [Display omitted] • A thermoelectrochemical conversion system of H+-ion concentration cell stack was studied. • It operated by the principle of H+-ion concentration difference to harvest electricity from low-grade heat. • H 2 consumed at the anode while regenerating at the cathode. • The 3-cell stack delivered a thermal-to-electric conversion efficiency of 17.86%. [ABSTRACT FROM AUTHOR]

Similar to MXene, MAB is a group of 2D ceramic/metallic boride materials which exhibits unique properties for various applications. However, these 2D sheets tend to stack and therefore lose their active surface area and functions. Herein, an amorphous cobalt nickel boride (Co–Ni–B) nanocomposite is prepared with a combination of 2D sheets and nanoparticles in the center to avoid agglomeration. This unique structure holds the 2D nano-sheets with massive surface area which contains numerous catalytic active sites. This nanocomposite is prepared as an electrocatalyst for borohydride electrooxidation reaction (BOR). It shows outstanding catalytic activity through improving the kinetic parameters of BH 4 − oxidation, owing to abundant ultrathin 2D structure on the surface, which provide free interspace and electroactive sites for charge/mass transport. The anode catalyst led to a 209 mW/cm2 maximum power density with high open circuit potential of 1.06 V at room temperature in a miniature direct borohydride fuel cell (DBFC). It also showed a great longevity of up to 45 h at an output power density of 64 mW/cm2, which is higher than the Co–B, Ni–B and PtRu/C. The cost reduction and prospective scale-up production of the Co–Ni–B catalyst are also addressed. [Display omitted] • DBFC with Co–Ni–B nanocomposite as anode catalyst exhibited P max = 209 mW/cm2 which is over twice higher than PtRu/C. • MXene-like structure enhanced the exposure of active metallic species and the mass transfer. • The assembled DBFC has good stability of retaining 91.2% of the output voltage after 45 h. • The narrow band gap of Co–Ni–B nanocomposite urges the charge transfer kinetic. [ABSTRACT FROM AUTHOR]

(1) The NiFeBO is consist of NiFe(OH) 2 layers and BO 2 − pillars. (2) The BO 2 − pillars enhance the stability of NiFe-LDH and show adsorption to hydroxyl ion due to the unsaturated electron state. (3) The addition of Fe and B elements reduces the band gap of α-Ni(OH) 2 , accelerating the catalytic process. (4) The introduced NiFeBO catalyst shows outstanding electrochemical activity for OER with low overpotential, small Tafel slope, and long-term stability. Water-splitting by electrolysis is one of the most important approaches to produce hydrogen as renewable clean energy with superior advantages of high-purity and good operability. But the key issue limiting the large-scale application is that it demands a much higher overpotential than the theoretical oxygen evolution potential. Herein, we report an efficient electrochemical catalyst of NiFeBO synthesized via a facile one-step process, presenting remarkable catalytic activity and long-term stability. In this work, we discussed the effects of the doping of Fe and the insertion of BO 2 − in the as-synthesized NiFeBO. According to the experimental results, NiFeBO shows a very low overpotential of 256 mV and a Tafel slope of 53 mV dec−1 with remarkable stability over 60 h of chronopotentiometry test. The inserted anion of BO 2 − can adsorb OH− in electrolyte around the catalyst to increase the concentration of OH− around the active sites, thereby improving the effectivity of oxygen evolution reaction. In addition, diffused micro-crystalline with different lattice formed during the oxidation of the as-synthesized catalyst, providing more active sites than the pristine amorphous. [ABSTRACT FROM AUTHOR]

H+-ion concentration cell, which can harvest thermal energy to generate electricity by hydrogen concentration difference principle with a fuel cell structure, is an innovative thermoelectric conversion device. In this system, phosphoric acid-doped polybenzimidazole (PA-doped PBI) membrane is a key component influencing the power generation performance of the cell. Herein, 30, 45, 60, 75, and 90 μm thick PBI membranes are successfully synthesized and doped with phosphoric acid. To achieve a good compromise between the proton conductivity and durability, the properties of PA-doped PBI membranes are experimentally evaluated to clarify the effect of the acid doping time and membrane thickness on cell performance. The results indicate that the higher the acid doping level, the worse the dimensional stability of the membrane. Also the thinner the PBI membrane, the smaller the membrane resistance to ions motion, while the poorer the stability. Upon reaction at 170 °C, this cell can boast a power density from 3.0 to 8.0 W m−2, which results in a thermoelectric conversion efficiency of 5.97–14.32%. This study potentially boosts the practical application of thermal-to-electrical conversion technology. Image 1 • The properties of different PBI membranes were studied. • Phosphoric acid-doped PBI membranes exhibited good proton conductivity and thermal stability. • The H+-ion concentration cell can boast a power density from 3.0 to 8.0 W m−2 at 170 °C. • The thermoelectric conversion efficiency across the H+-ion concentration cell is in the range of 5.97–14.32%. [ABSTRACT FROM AUTHOR]

In recent years, the oxygen reduction reaction (ORR) performance of N-doped carbon catalysts has made great progress and is now comparable to that of commercial Pt/C. However, the rich porous features of N-doped carbon catalysts give them a very low bulk density, which leads to problems in oxygen mass transfer due to water flooding when they are used as the cathode in fuel cells. Herein, a controllable mesoporous surface of nitrogen-doped yolk-shelled carbon spheres (N-YS-CS) with an extremely regular particle size was synthesized. The mesopores of the N-YS-CS effectively store the hydrophobic agent and form robust hydrophobic tunnels within the close-packed N-YS-CS units, forming an excellent structure for mass transfer at the cathode. This elaborately constructed hydrophobic cathode structure has a larger triple-phase interface than traditional carbon paper in an electrolyte-penetration-type direct methanol fuel cell (DMFC) with a polymer fiber membrane (PFM), and delivers a high power density (55 and 142 mW cm −2 at 25 °C and 60 °C, respectively) and discharge stability (a run time of over 210 h). [ABSTRACT FROM AUTHOR]

Lithium metal has been considered one of the most ideal anode materials for batteries due to its ultrahigh theoretical capacity and energy density. However, the unstable SEI layer and the growth of Li dendrites cause poor cycling performance and even safety hazards, which also severely restrict the commercial application of Li metal batteries. In this paper, a Li-In alloy anode was designed and prepared by mechanical rolling of both Li and In pure metal foils together. Three-dimensional Li-In alloy network structures are formed by mechanical alloying during rolling, and the 3D Li-In alloy structure not only possesses strong lithium affinity but also possesses more interface between the Li matrix and the second phase formed in mechanical alloying, which can promote rapid diffusion at the interface and uniform deposition of lithium ions. As a result, the Li-In electrode shows an extremely low overpotential of approximately 35 mV at a high current density of 5 mA cm−2 during the lithium plating/stripping experiment. In addition, the battery revealed a higher discharge capacity of 295 mAh/g at 0.05 C and capacity retention of 80 % after 150 cycles when the Li-In alloy was used as the anode electrode in a cell with Li 1.2 Ni 0.2 Mn 0.6 O 2 as the cathode. The Li-In alloy can also be used as anode of Li-S battery, the result showed that the capacity decay rate was reduced from 0.22 % to 0.1 % after 200 cycles without any decoration treatment of S cathode except conductive carbon. This work verified that indium in the Li-In alloy can effectively protect the lithium anode and provides an idea for the practical application of lithium metal batteries. [Display omitted] • The Li-In alloy with three-dimensional (3D) interconnected network are formed by mechanical alloying. • The Li-In alloys exhibit strong lithium affinity and rich interfaces. • The alloy anode promotes the uniform deposition of lithium ions to prevent the generation of lithium dendrites. • The alloy electrodes exhibit excellent electrochemical properties for lithium metal batteries. [ABSTRACT FROM AUTHOR]

The Au@Co-B nano-particles are prepared by chemical reduction and used as anode catalyst in direct borohydride fuel cells (DBFCs). The physical and electrochemical properties of the catalyst are investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), and fuel cell tests. The physical characterisation demonstrates that the crystalline Au particles are wrapped by amorphous Co-B, and the average size of Au@Co-B particles are about 15 nm. The fuel cell tests prove that the kinetics property of Au@Co-B is improved significantly and material cost reduced obviously compared with pure Au catalyst for DBFC. The maximum power output of 85 mW cm −2 is achieved at 25 °C for this cell without using any ion exchange membranes. This power density performance is also better than some noble metal and bimetallic anode in DBFCs which reported in literatures. And this cell also has a good durability, with no attenuation observed after 80 h of operation. [ABSTRACT FROM AUTHOR]

Abstract: LaNi0.9Ru0.1O3 as cathode catalyst for a direct borohydride fuel cell (DBFC) was synthesized and investigated for the first time. The electrochemical experiments indicated that perovskite-type oxide LaNi0.9Ru0.1O3 exhibited higher electrochemical performance compared with LaNiO3, which suggested incorporation of element Ru into LaNiO3 could further improve the catalytic ability for oxygen reduction reaction (ORR) in alkaline solution. LaNi0.9Ru0.1O3 catalyst was found to have good tolerance of BH4 −. Meanwhile the maximum power density of 171mWcm−2 was obtained at 65°C without using any precious ion exchange membrane. A life test indicated that the DBFC displayed no significant degradation for about 70h testing. The electrochemical data suggested that LaNi0.9Ru0.1O3, which provided a simple way to construct DBFCs without using any ion exchange membrane, might be promising cathode catalyst with high performance and low cost for DBFCs. [Copyright &y& Elsevier]

Abstract: In this paper, cobalt(II) oxide (CoO) has been used as an anode catalyst in a direct borohydride fuel cell (DBFC). The microstructure of CoO has been characterised by X-ray diffraction. The cell performance and short-term performance stability of the DBFC using the CoO as anode catalyst have been investigated. At the optimum conditions, the maximum power density of 80mWcm−2 has been achieved at 30°C for this cell without using any precious metals and ion exchange membranes. Results from XRD, TEM, and XPS analysis confirm that the good performance of the fuel cell is attributed to the co-operation of CoO and CoB which formed from CoO during the operation. [Copyright &y& Elsevier]