Comparative life cycle assessment of Fe2O3-based fibers as anode materials for sodium-ion batteries

AbstractSodium-ion batteries (SIBs) potentially represent a more sustainable, less expensive and environmentally friendly alternative to lithium-ion batteries. The development of new low-cost, non-toxic, highly performing electrode materials is the key point for the SIB technology advances. This study develops a basic life cycle assessment (LCA) model for the evaluation of the production by electrospinning of iron (III) oxide-based fibers to be used as anode materials in SIBs. Indeed, it has been recently demonstrated that electrospun silicon-doped iron (III) oxide (Fe2O3) fibers exhibit outstanding electrochemical properties and gravimetric capacities never achieved before for pure Fe2O3-based anodes. The LCA methodology is utilized in order to analyze the environmental burdens (from raw material extraction to manufacturing process) of these electrode materials. The simplified comparative LCA studies, conducted to assess the environmental impacts associated with the electrospun Fe2O3 and Fe2O3:Si fibers at the same cell performance, demonstrate that the Si-doped anode material, which exhibits better electrochemical performance with respect to the undoped one, has also lower impact for each category of damage, namely human health, ecosystem quality and resources

Electro-spun graphene-enriched carbon fibres with high nitrogen-contents for electrochemical water desalination

Electro-spun carbon fibres doped with very high nitrogen concentrations (19–21 wt%) are obtained operating carbonisation at low temperature (500 °C). The as-synthesised fibres are evaluated as electrode materials for the electrochemical desalination of water. The effect of the enrichment of the nitrogen doped carbon fibres with thermally reduced graphene oxide is also investigated. The fibrous electrodes are able to remove amazing amounts of NaCl (17.0–27.6 mg/g) from a salty solution with an initial concentration of 585 mg/L. The nitrogen doping, which dramatically improves the wettability, plays a crucial role in determining the outstanding electro-sorption capacities of the fibres. It allows fully profiting of the more favourable pore size distribution in the graphene-enriched fibres, endowed with higher conductivity and capacitance, for the obtainment of unprecedented electro-sorption capacities via an extremely simple synthesis process, with no need of activation treatments

Evaluation of the electrochemical performance of electrospun transition metal oxide-based electrode nanomaterials for water CDI applications

Composite fibrous materials based on (graphene-enriched) nitrogen-doped carbon/transition metal oxides were produced by electrospinning and their physicochemical properties were thoroughly investigated by a combination of characterisation techniques. The electrochemical behaviour of the electrodes prepared with them was evaluated in view of their use in the capacitive deionisation of saline water. The morphology of the materials reminded of usnea florida lichens, wheat ears, sea sponges and noodles and depended on the transition metal (Mn, Fe, Ti or Zn). The morphology and the relative amount (14.1–22.2 wt%) of the surface nitrogen and carbon-bonded oxygen functional species, beneficial to wettability and involving pseudocapacitive processes, had strong impact on the specific capacitance (43.7–67.4 F g−1, at 5 m V s−1 scan rate), whereas also the specific micropore volume (0.4–5.6 mm3 g−1) affected the effective areal capacitance of the electrodes (1.2–6.0 F m−2, at 5 mV s−1). Ion storage in the composite materials occurred via a mixed capacitive/pseudocapacitive process. Hence, increasing the content of the oxide (from 24.6 to 56.7 wt%), thanks to the fast-reversible redox reactions at or near surface it involves, partly compensated for the growing hindrance to diffusion encountered by the ions (hampered electrostatic adsorption) as the scan rate increased from 5 to 100 mV s−1

Trimetallic Ni-Based Catalysts over Gadolinia-Doped Ceria for Green Fuel Production

The present work concerns the characterization of trimetallic nickel catalysts, NiMoRe (Nickel/Molybdenum/Rhenium), NiMoCu (Nickel/Molybdenum/Copper) and NiMoCo (Nickel/Molybdenum/Cobalt), supported on gadolinia-doped ceria and the evaluation of their catalytic performance in the auto-thermal reforming of ethanol to hydrogen. Catalysts have been prepared by wet impregnation and characterized by XRD, SEM-EDX, TG-DSC, TEM, CHNS, H2-TPR and micro-Raman spectroscopy. The resistance of Ni-alloy catalysts to the carbon deposition and sulfur poisoning has been studied. All catalysts show a similar behavior in the auto-thermal reforming reaction: 100% of ethanol conversion and high selectivity to syngas products, up to 77 vol.%. At 800 °C the coke deposition is very low (less than 0.34 wt%). Sulfur content affects the selectivity and the activity of the catalysts, especially towards the coke formation: high sulfur content promotes the ethylene formation, therefore the amount of coke deposited on spent catalyst increases. NiMoCu seems to be the trimetallic catalyst less sensitive to this aspect

Supported Catalysts for CO2 Methanation: A Review

CO2 methanation is a well-known reaction that is of interest as a capture and storage (CCS) process and as a renewable energy storage system based on a power-to-gas conversion process by substitute or synthetic natural gas (SNG) production. Integrating water electrolysis and CO2 methanation is a highly effective way to store energy produced by renewables sources. The conversion of electricity into methane takes place via two steps: hydrogen is produced by electrolysis and converted to methane by CO2 methanation. The effectiveness and efficiency of power-to-gas plants strongly depend on the CO2 methanation process. For this reason, research on CO2 methanation has intensified over the last 10 years. The rise of active, selective, and stable catalysts is the core of the CO2 methanation process. Novel, heterogeneous catalysts have been tested and tuned such that the CO2 methanation process increases their productivity. The present work aims to give a critical overview of CO2 methanation catalyst production and research carried out in the last 50 years. The fundamentals of reaction mechanism, catalyst deactivation, and catalyst promoters, as well as a discussion of current and future developments in CO2 methanation, are also included

Special Issue on Advanced Materials and Nanotechnology for Sustainable Energy and Environmental Applications

Materials play a very important role in the technological development of a society, greatly impacting people’s daily lives [...

Special Issue on Advanced Materials and Nanotechnology for Sustainable Energy and Environmental Applications

Materials play a very important role in the technological development of a society, greatly impacting people’s daily lives [...

Advanced Adsorbent Materials for Waste Energy Recovery

Nowadays, waste thermal energy represents a huge quantity of energy that, in most cases, is unfortunately dispersed rather than recovered. Although it is well known that its recovery could result in a considerable impact reduction of human activities on the environment, it is still a challenging issue. In view of this, absorption chillers and heat pumps, based on the use of porous materials capable of reversibly adsorbing and desorbing water vapor, can be considered among the preferred systems to recover waste thermal energy, especially at medium–low temperatures. This study deals with the preparation and performance of a new generation of advanced adsorbent materials specifically produced as coatings for water adsorption systems driven by low temperature heat sources (around 150 °C). The proposed coating consists of hybrid SAPO-34/polyacrilonitrile microfibers directly deposited on the surface to be coated by means of the electrospinning technique. Their zeolite morphology and concentrations, as well as their distribution over the polymeric microfibers, were key variables in achieving the best combination of adsorption properties and hydrothermal stability of the coating

Supported Catalysts for CO2 Methanation: A Review

CO2 methanation is a well-known reaction that is of interest as a capture and storage (CCS) process and as a renewable energy storage system based on a power-to-gas conversion process by substitute or synthetic natural gas (SNG) production. Integrating water electrolysis and CO2 methanation is a highly effective way to store energy produced by renewables sources. The conversion of electricity into methane takes place via two steps: hydrogen is produced by electrolysis and converted to methane by CO2 methanation. The effectiveness and efficiency of power-to-gas plants strongly depend on the CO2 methanation process. For this reason, research on CO2 methanation has intensified over the last 10 years. The rise of active, selective, and stable catalysts is the core of the CO2 methanation process. Novel, heterogeneous catalysts have been tested and tuned such that the CO2 methanation process increases their productivity. The present work aims to give a critical overview of CO2 methanation catalyst production and research carried out in the last 50 years. The fundamentals of reaction mechanism, catalyst deactivation, and catalyst promoters, as well as a discussion of current and future developments in CO2 methanation, are also included

Fibrous Materials for Potential Efficient Energy Recovery at Low-Temperature Heat

Technology must improve energy generation and utilization to support human societies. All highly industrialized nations support the attempt to switch from fossil fuels to renewable energy sources—a process which is irreversible—but the support is not yet strong enough to make the switch. Energy-efficient and renewable heating and cooling systems offer considerable energy saving potential, since buildings use a large percentage of EU energy for heating and cooling, which still uses fossil fuels (75%). For this transition, innovation regarding the traditional material for thermal energy storage appears to be crucial. This work proposes a review of a new approach to thermochemical materials for energy recovery in the low-temperature range, based on the production of microfibers by electrospinning. The novelty of applying fibrous materials in thermal energy storage systems is related to the particular configuration of the adsorbing phase and the production technique used. Microfibers show a large surface area, high vapor permeability, and high structural stability, and they can be easily electrospun to form self-standing foils or coatings for heat exchangers