bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regeneration of Activated Carbon Using Electric Potential for Upgrading Bio-Gas to Bio-Methane
Authors: Farooq Muhammad , Andresen John 
Published: February 2020

The anaerobic digestion (AD) industry in the UK has experienced rapid growth in recent years over 130 operational AD plants in the UK outside the sewage treatment sector and more than 340 further projects are under development. Thus, there is an increasing demand for upgraded biogas to be used as vehicle fuel or injected to the natural gas grid. Since a typical biogas contains 1000 - 10,000 ppm hydrogen sulphide, its removal below 5ppm is required for uses beyond combined heat and power (CHP). Although a number of established methods exist for removal of hydrogen sulphide they tend to be costly. A common industry practice is to adsorb hydrogen sulphide using a granular activated carbon (GAC) bed which is subsequently disposed as hazard waste. Accordingly, this research is focused on regeneration of activated carbon using an electric potential. Fine diameter MI construction thermocouples are used for this purpose. Thermocouples are terminated with a miniature plug. The driving force is a high capacity system that is regenerative, inexpensive and leaves no waste. Initially, 1% hydrogen sulphide / 99% nitrogen gas mixture is used as a benchmarked against an industrial activated carbon specifically used for hydrogen sulphide removal. Several Electric Conductive Activated Carbons (ECAC) will then be reported for their adsorption/ desorption potential. It is envisioned that this method can transform the production of bio-methane where early estimates have calculated that a regenerative system could save up to 50% of running costs.

Key Words:
Biogas, Electric conductive activated carbons, Thermocouples.
Polysulphide Air Redox Flow Battery - a Novel Solution for Grid Scale Energy Storage
Authors: Xia Yuhua , Yufit Vladimir , Brandon Nigel P. 
Published: February 2020

The widespread deployment of flow batteries, an important part of energy storage technologies, has been largely restricted by its high cost. A novel, recently patented redox flow system utilising polysulphide redox and oxygen reduction/evolution reactions offers a cost effective solution for electricity storage and delivery.
The schematic operation of polysulphide-air flow battery is illustrated in the Figure below. The polysulphide anolyte is pumped through the porous media at the anode compartment when the reversible electrochemical redox reaction of soluble polysulphide/sulphur occurring. Concurrently the oxygen reduction/evolution occurs at catalytically active gas diffusion media at the cathode compartment. Experimental testing of polysulphide-air system was carried out in 5 cm2 active area single cell setup connected to peristaltic and air pumps. The stable open circuit voltage of 0.68 V was achieved in 0.5 Na2S/ 0.5 M S/ x 1M NaOH solution. This OCV was slightly lower than the theoretical value of 0.85V likely due to crossover of anolyte species and bad contact of circut. A maximum power density of 2.1 mW/cm2 was achieved during the discharge. To decouple anode and cathode processes half-cell measurements including electrochemical impedance spectroscopy were performed. The collected data clearly indicate that the major losses happened on polysulphide side. Increased flow rate of polysulphide anolyte just slightly improved the performance. This work will present novel data with improved catalytic activity of polysulphide side and increased performance of the polysulphide-air system.

Figure 1
Challenges and Progress in Membranes, Catalysts, and Meas for PEM Water Electrolysis
Authors: van Dijk Nicholas , Payne Johnson Elisabeth , Dodwell James , Lister Rachel , Platt Laura , Brightman Edward , Hinds Gareth 
Published: February 2020

In a world in which fossil fuel energy is becoming ever more scarce and expensive and countries are struggling to meet their carbon reduction obligations, hydrogen solutions have finally reached the top of energy agendas. The only industrially applicable zero carbon method to produce hydrogen is via electrolysis utilizing renewable sources of electricity.
ITM Power is at the very heart of the initiatives and programmes to adopt hydrogen technology that will reduce both carbon footprints and energy costs. Using its technology and knowhow, ITM is aiming to be the world leading supplier of both infrastructure for the production of green hydrogen transport fuel, and products for the generation and storage of hydrogen fuel from internittent renewable energy sources.
Despite having a number of electrolyser products on the market, ITM Power have an active PEM electrolyser research and development programme aimed at the next generation of electrolysers. Some of the electrochemical and materials challenges faced by both ITM and the industry will be presented along with recent results, examples given below.
PEM electrolysers have a lifetime of 5-10 years; as such there is difficulty in getting new materials to market. ITM along with the National Physical Laboratory have used a novel in-situ reference electrode to help understand catalyst degradation within the cell. This approach enables separation of the relative contributions of anode and cathode to the overall reaction. During shut down periods it was observed for the first time that the cathode contributes more to changes in the open circuit voltage. This knowledge has been used to show that the majority of the degradation is occurring on the cathode catalyst, which is in contrast to the perceived thought which assumes the anode degrades faster. Changes in the electrochemically active surface area of the platinum cathode as a result of potential cycling were determined in-situ via hydrogen underpotential cyclic voltammetry. Scanning electron microscopy and X-ray tomography were used to correlate changes in catalyst morphology with performance degradation of both carbon-supported and unsupported platinum catalysts. These experiments have led to the development of accelerated stress tests, based on cycling of the electrode potential, for PEM electrolyser catalysts.
In addition ITM have made progress in the development of new membranes for PEM electrolysis. ITM’s approach to membrane development is the UV polymerisation of low cost hydrocarbon monomers. A new highly conductive membrane has been developed and tested to 3 A∙cm-2. This membrane is 125 um thick to minimise hydrogen crossover, has a conductivity of 260 mS∙cm-1 and is extremely low cost. When made into a MEA, this membrane allows a voltage of below 1.6 V at 1 A∙cm-2 at only 55°C. This has been benchmarked against Nafion(R)115.
New Progress in Ruthenium Based Oxygen Reduction Catalysis
Authors: Schechter Alex , Teller Hanan , Krichevski Olga 
Published: February 2020

Platinum-based catalyst, the stat- of- the-art in oxygen reduction catalysis in PEMFC is also one major factor, impeding the commercialization of this energy conversion technology. This is mostly due to high Pt cost and insufficient durability during prolong FC operation time. Recently, there is a growing interest in Pt free oxygen reduction reaction (ORR) catalysis for acidic fuel cells. Ruthenium chalcogenide catalysts have been reported to present highly stability and fair activity in acid environment [1,2].
In this study, ruthenium selenide, phosphide and ternary RuCoSe were synthesized using various methods, following by a rigorous study of their activity, as oxygen reduction catalysts in acid solutions.
The synthesis of selenide-based nano size particles was carried out in a rather straightforward manner, using microwave assisted polyol and sodium borohydride reduction method and inorganic RuCl3, CoCl3 and Se or H2SeO3. However, the preparation of RuP and Ru2P has been found to be much more challenging. These methods include reaction at high temperature in closed vessel under autogenic pressure.
ORR study on ruthenium-based catalysts in 0.5M sulfuric acid solution was studied using rotating disk ring electrode RRDE method coupled by surface and bulk and Raman, XPS and EDS and XRD spectroscopic methods coupled with SEM and TEM microscopy. We have found that there are more than single active sights. The number of these sights is controlled by the bulk and surface composition as well as surface oxides formed on the particles at high potentials. Interestingly, most of the O2 reduction proceed directly to water via 4e- reduction process. Calculated rate consents suggest that reduction by 2e to H2O2plays a major role at high potential, whereas at low potentials the reaction proceed by direct reduction of 4e-.
Extremely high selectivity in the presence of methanol was measured (methanol tolerance) was found in Ru2Se (figure 1).
Figure 1.
Oxygen reduction on Ru2Se and Pt in the presence of methanol

(electrode polarized to 0.4 V)

[1] I. V. Malakhov, S. G. Nikitenko, E. R. Savinova, D. I. Kochubey, and N. Alonso-Vante, J. Phys. Chem. B 2002, 106, 1670-1676
[2] Georgios A. Tritsaris, Jens K. Nørskova, Jan Rossmeisla, Electrochimica Acta 56 (2011) 9783– 9788

Figure 1
Understanding Ionomer in Fuel-Cell Catalyst Layers
Authors: Weber Adam Z , Kusoglu Ahmet , Tesfaye Meron 
Published: February 2020

One of the keys to optimizing polymer-electrolyte-fuel-cell performance is understanding it’s transport phenomena. This is especially critical in the polymer electrolyte in both the bulk and in particular the catalyst layers, where it exists as thin, nanometer-thick film covering the catalyst agglomerates. In these structures, it is known to perhaps inhibit performance, especially as the total platinum content is reduced. Interactions of the membrane with the local environment and as a thin film within the CL result in highly complex material behavior that is highly dependent on the environmental conditions, ionomer thickness, and the material interactions, e.g., carbon, platinum, etc. Thus, characterization of the role of ionomer in fuel-cell catalyst layers requires understanding the transport properties and water-uptake behavior throughout a wide thickness range.
In this talk, the role of the ionomer and its underlying structure/function relationships will be elucidated. Ex-situ testing of the catalyst-layer ionomer demonstrates reduced water content for both Nafion and the short-side-chain, lower equivalent weight 3M ionomer. These studies are complemented by thin-film structural and swelling measurements using x-ray scattering and ellipsometry, respectively, which likewise show reduced water content and phase separation as the film thickness decreases. This decrease is caused by an increase in the packing of the polymer chains resulting in increases in mechanical modulus. In addition, direct measurement of the permeability of thin-films is accomplished, again showing that the thin films may result in substantial mass transport limitations.
Acknowledgement
The authors thank Steve Hamrock and Mike Yandrasits from 3M for helpful discussion and ionomer samples as well as Kunal Karan, Kirt Page, Chris Stafford, and Mike Hickner for discussions. This work made use of facilities at the Advanced Light Source (ALS), supported by the Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy. This work was funded by the Assistant Secretary for Energy Efficiency and Renewable Energy, Fuel Cell Technologies Office, of the U. S. Department of Energy under contract number DE-AC02—05CH11231 and a CRADA with Toyota Motor Company.
Nitrogen-Doped Graphene Foam As a Metal-Free Electrocatalyst
Authors: Lyth Stephen Matthew , Liu Jianfeng , Sasaki Kazunari 
Published: February 2020

Pt nanoparticles are generally used as the electrocatalyst in proton exchange membrane fuel cells (PEMFCs). However Pt is expensive, and has limited durability due to agglomeration, dissolution, and carbon corrosion in the harsh environment of the fuel cell cathode. Alternative electrocatalysts have been proposed; one of the most popular being Fe/N/C-based electrocatalysts. However, these non-platinum group metal (non-PGM) electrocatalysts struggle to compete with platinum in terms of performance and durability in the acid environment of a PEMFC.
In alkaline media, the oxygen reduction reaction (ORR) kinetics are much faster, and this means that non-PGM electrocatalysts can compete with Pt. Until recently, anion exchange membrane fuel cells (AEMFCs) were not considered to be able to compete with PEMFCs. However, recent advances in membrane technology have made them more viable.
Here, we show that even a completely metal-free nitrogen-doped carbon can have electrochemical ORR activity comparable to that of platinum. Moreover, we perform electrochemical load-cycle durability tests and show that even after 60,000 potential cycles negligible degradation is observed for this electrocatalyst system in alkaline. In contrast, the performance of Pt is much worse after the same test. In conclusion, non-precious nitrogen-doped graphene foam is a potential electrocatalyst for the oxygen reduction reaction in alkaline anion exchange membrane fuel cells.
Phosphate Based Ceramics As Solid Electrolyte for High Temperature Lithium Ion Batteries
Authors: Cui Yuantao , Rohde Magnus , Mahmoud Morsi M , Ziebert Carlos , Seifert Hans Jürgen 
Published: February 2020

A Li-ion battery with liquid electrolyte may suffer from security risks such as inflaming or short circuits. A solid electrolyte made of ion conducting glass-ceramic is thermally more stable. If the ion conducting ceramics as combined electrolyte and separator could be used in a battery, the battery will be safer.
LAGP (Li1+x AlxGe2-x (PO4)3) was investigated as a candidate for solid electrolytes in Li ion batteries. LAGP glass samples were produced using the melt-quench-method. Samples were fabricated using powder compaction by sintering or by direct heat treatment of the glass. Their ionic conductivities were measured with impedance spectroscopy. Dilatometer measurements, X-ray diffraction and scanning electron microscope analysis were also carried out. The thermal properties like crystallization temperature, heat capacity and thermal conductivity were measured with differential scanning calorimeter and Laser-Flash apparatus.
Multiple batches of LAGP with different composition were produced. The ionic conductivity of 3·10-4 S/cm at room temperature and 1·10-2 S/cm at 150°C was achieved. The relationship between the process parameters, the microstructure and ionic conductivity of the solid electrolyte was studied. Also, their influence on the heat capacity and the thermal conductivity was studied.
All-solid test cells were fabricated using LAGP ceramic as solid electrolyte. Magnetron sputtering, spark plasma sintering and furnace sintering were used to produce the anode-electrolyte-cathode multilayer tablets. The tablets were assembled in swagelok-cells and tested between 100°C and 200°C.
Study on the Electrochemical Performance of Poly(ethylene ether carbonate) (PEEC)-Based Polymer Electrolyte for All Solid-State Lithium Batteries
Authors: Jung Yun-Chae , Kim Duck-Hyun , Shin Woo-Cheol , Ue Makoto , Kim Dong-Won 
Published: February 2020

Lithium-ion batteries have rapidly become the dominant power sources for portable electronic devices and electric vehicles, due to their high energy density and long cycle life.[1,2] However, safety issues have become a significant concern owing to the use of flammable liquid electrolytes. In this respect, the development of non-flammable solid electrolytes may provide a fundamental solution to the safety issue of lithium batteries. Solid polymer electrolytes based on poly(ethylene oxide) (PEO) present advantageous features such as flexibility in the shape of battery design, absence of leakage of organic solvents and better safety than liquid electrolytes.[3] However, they show poor ionic conductivity at ambient temperatures due to their tendency to crystallize. Moreover, their poor mechanical properties at high temperature due to the melting transition may cause short circuits between two electrodes in cases where unusually high heat is generated. In order to overcome these problems, we prepared polymer electrolytes based on alternating copolymer composed of ethylene oxide and ethylene carbonate (poly(ethylene ether carbonate), PEEC) in the form of flexible thin film, and their electrochemical properties were investigated. The polymer electrolytes showed higher ionic conductivity and superior electrochemical stability compared to those of PEO-based polymer electrolyte. The polymer electrolytes were applied to the all solid-state lithium batteries, and their electrochemical performance was evaluated.
References

[1] J. M. Tarascon, and M. Armand, Nature, 414 (2001) 359.
[2] P. G. Bruce, B. Scrosati, and J. M. Tarascon, Angew. Chem. Int. Ed. 47 (2008) 2930.
[3] E. Quartarone, and P. Mustarelli, Chem. Soc. Rev. 40 (2011) 2525.
High Throughput in-Situ Analysis of Gas Evolution in Lithium Ion Batteries
Authors: Clemmons James Owen 
Published: February 2020

Gas evolution as a result of electrolyte decomposition during the formation operation and storage of rechargeable lithium ions batteries is a common problem for high performance lithium-ion batteries as cell makers and material suppliers strive to find solutions enabling cells to function at increased voltages in the quest for greater energy. Outgassing during cell formation requires cell manufactures to degass cells thus leading to increased manufacturing costs. Gas evolution during the cycling and high temperature storage of cells can lead to potential safety hazards while also contributing to capacity fade and cell deformation especially in pouch cells. Unfortunately, the detection of origin of gas evolution is challenging due to the lack of capability of in-situ gas measurement. Conventional methods such as the Archimedes water-displacement test, allows one gas measurement after cell testing which makes it impossible to track when gas was generated and consumed, while other in-situ techniques are extremely complicated and only allow a few experiments to be run at a time. Wildcat has developed a novel high throughput gas cell architecture which allows for the monitoring of gas in-situ.
Using high throughput gas cells, a gas measurement is taken every 0.1 seconds throughout any given electrochemical test which allows for the evaluation of gas evolution for hundreds of cells run in parallel. This allows for Wildcat’s scientists to rapidly evaluate thousands of electrolytes in full cells, while simultaneously evaluate their cycling or storage performance, thus allowing for the dramatic acceleration of electrolyte development. In addition to the development aspect Wildcat has found this technique often shines the light on the understanding of electrolyte decomposition mechanisms. By presenting various case studies this presentation hopes to illustrate the power of Wildcat’s high throughput in situ gas cells.
Development of High Energy Cathode Phosphates Via High Throughput Methods
Authors: Yang Johnny , Li Bin 
Published: February 2020

Olivine phosphates as cathode material became attractive due to the greater structural stability of (PO4)3- units compared to other counterparts like LiCoO2, LiNixMnyCozO2 and LiMn2O4. Since 1997 Goodenough’s group had introduced LiFePO4 as cathode material, it has been one of the major cathode materials, especially in China EV battery market currently. However, the energy density (578 Wh/kg) is limited due to the low operating potential 3.4 V vs. Li. Development of high energy density (700 Wh/kg) LiMnPO4 cathode material became attractive due to its high operating voltage 4.1 V vs. Li, which falls within the electrochemical stability window of conventional electrolytes.
With Wildcat Discovery Technologies’ high throughput research workflow, we developed a low cost and scalable method for LiMnPO4 with capacity > 150 mAh/g, 1C rate > 95%, and > 90% capacity retention over 500 cycles. This research was systematically studied in precursor selection, doping screen, composition, coating, synthesis conditions and electrolyte formulation screen. Moreover, this technology has been successfully demonstrated in 1Kg per batch synthesis.
In Situ Transmission FTIR Spectroscopy Investigation of the Electrolyte Oxidation Reaction Under High-Voltage
Authors: Wang Long , Ma Yulin , Qu Yunteng , Gao Yunzhi , Yin Geping 
Published: February 2020

At high potential, lithium-ion battery electrolyte solvent will decompose to some extent under different voltages due to their intrinsic instability as well as the catalytic effects on the electrode material surface. The generated gas increases internal pressure of lithium ion battery, namely flatulence phenomenon, and the batteries was prone to explode. Investigating the influence of electrolyte composition, electrolyte salts, electrolyte electrode material during the charging and discharging process, drawing the electrolyte decomposition law will be beneficial to optimize the electrolyte component. In this work, the gas evolution behavior in EC/DMC (volume ratio 1:1) electrolyte system was carried out investigation during the first charging process at high voltage with LiNi0.5Mn1.5O2 material as working cathode. The transmission infrared spectrum testing equipment was shown in Figure 1.
The coin cell for transmission infrared spectrum test was prepared and the test scheme was shown as follows: constant current charging, current density of 20 mA/g; voltage range of 3.5-5.0 V. The infrared spectra is collected every interval 0.1V. The infrared spectra collected in different electrolytes at different voltages during the charging process was given in Figure 2. As seen, the wave number corresponding to different functional groups are listed: absorption peak around 3000 cm-1 corresponds to the -CH symmetrical stretching vibration, absorption peak at 2360, 2340cm-1 corresponds to CO2 gas, absorption peak around 1802, 1770 cm-1 corresponds to C=C bond stretching vibration, the peak around 1282 and 1165 cm-1 corresponds to C-H bending and CF3 degenerate stretching of CHF3.

Figure 1