bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Li2MnO3 Performance on Electrochemical Properties of Li-Rich Composite Layered Cathode
Authors: Fung Kuan-Zong , Tsai Shu-Yi , Chang Li-Fu , Liu Chi-Yang 
Published: February 2020

Composite layered cathode materials formulated as xLi2MnO3-(1-x)LiMO2(M = Mn, Ni, Co, etc.) show their surprisingly high reversible capacity and have received much attention for Li-ion battery applications. It is known that Li2MnO3 has played important role of providing extra Li source for stabilizing the layered structure. However, single phase Li2MnO3 has shown very limited capacity during charging/discharging reaction. Very interestingly, there is a characteristic 1st charging plateau corresponding to the extended capacity contribution from oxygen oxidation in Li2MnO3. Furthermore, such oxygen oxidation also causes the formation of oxygen defects (vacancies) and may cause the subsequent capacity fading. In order to obtain a stable and high capacity Li-rich composite oxides cathode with layered structure, it is important to investigate and to improve the electrochemical properties of Li2MnO3 with a systematic study. Therefore, the main objective of this study is (i) to modify the defect structure of Li2MnO3 through changing oxygen partial pressure during synthesis, (ii) to use dopants to introduce more electrons to Li2MnO3 for better electronic conduction, (iii) to assemble and test cells using Li2MnO3 as the cathode and Li metal as the anode, (iv) to characterize and understand the electrochemical properties of Li2MnO3 that are under various treatments.
In this study, Li2MnO3 are prepared using sol gel process and followed by treatment with different atmospheres. Proper dopants with various concentrations will be added into Li2MnO3 for enhanced conduction and better stability. Impedance of Li2MnO3 will be measured using Electrochemical Impedance Spectroscopy (EIS). XRD analysis and SEM observation will be performed for synthesized Li2MnO3 particles. A full cell based on Li/ Li2MnO3 and Li/ 0.5Li2MnO3-0.5LiMO2 using treated or doped Li2MnO3 will be assembled and tested.
Metal-Ion Batteries Based on New Copper and Nickel Coordination Polymers with Aromatic Polyamine Ligands
Authors: Kapaev Roman R. , Stevenson Keith J. , Troshin Pavel A. 
Published: February 2020

Redox-active materials with high electron and ion conductivities are required for the new generation of metal-ion batteries (MIBs) with high energy density and high rate capability. Recently, a novel family of conductive (>1 S/cm) and electrochemically active metal organic frameworks (MOFs) composed of aryl amine ligands and bivalent transition metal ions (Cu2+, Ni2+, Co2+) has been reported. However, this class of MOFs remains virtually unexplored in metal-ion batteries. In particular, the only structures tested in MIBs are based on hexaaminobenzene, a molecule that readily decomposes or gets oxidized during synthesis or while handling, which limits its applicability.
Here we report new Ni(II) and Cu(II) coordination polymers derived from commercially available or easily synthesizable polyamines, e.g. 1,2,4,5-tetraaminobenzene tetrahydrochloride (TAB*4HCl), etc. A series of target MOFs was synthesized by simply mixing the ligand and the transition metal salt in the presence of air and ammonia. The novel materials are characterized using a set of complementary techniques including solid-state NMR, elemental analysis, IR spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy (XPS) and electron microscopy. Their electrochemical behavior is rationalized using impedance spectroscopy monitoring and ex situ XPS.
The obtained MOFs were successfully applied as both cathode and anode materials in lithium- and sodium-ion batteries and demonstrated ultra-high rate capability and stability. For example, a specific capacity of 83 mAh/g can be reached for the Ni(II) polymer derived from TAB*4HCl at 20 A/g current rate (>250 C) in 0.8-2.0 V vs. Li/Li+ range, while 79% of this capacity is retained after 20000 cycles. Another example is the Cu-TAB coordination polymer, which shows a specific capacity up to 262 mAh/g in 1.5-4.1 V vs. Li/Li+ range, which corresponds to the energy density of 616 Wh/kg.
The revealed correlations between the molecular structures of MOFs, their physicochemical properties and electrochemical performance pave a way to rational design of new coordination polymers for advanced metal-ion batteries.
Electrolyte Solvent Mixtures for a Symmetric, Non-Aqueous Redox Flow Battery Based on [Fe(bpy)3][Fsi]2
Authors: Blesch Thomas , Cabral Diogo Moulin , Howlett Patrick C , MacFarlane Douglas R. 
Published: February 2020

Redox flow batteries (RFBs) store energy in liquid redox-active electrolytes which are charged and discharged while flowing through an electrochemical cell. This separation of storage and reaction sites enables flexible scalability of power and energy density. [1] Research suggests that non-aqueous RFB systems offer a promising combination of cost and performance for stationary applications, such as storage of excess renewable energy from domestic- to grid-scale [2].
In this work, we investigate a RFB based on the iron(II)-tris(2,2’-bipyridine) bis(fluorosulfonyl)imide complex, which shows one metal-centred oxidation process and up to three ligand-centred reduction processes, providing 2.4 V cell potential [3]. Using the same active material on both positive and negative sides of the cell mitigates the detrimental effects of cross-over through the separator membrane.
These redox processes are solvent-dependent [3] and their electrochemistry was studied in a range of aprotic single and mixed solvents, some already used in lithium-ion batteries [4]. Since energy density is determined by the cell potential and the concentration of the active material, the solubility of the reduced and oxidated states of the complex was examined by UV/vis spectroscopy. Furthermore, conductivity and viscosity were measured over a range of temperatures. In RFBs, the dynamic viscosity of the electrolyte influences not just the conductivity but also affects the power required to pump the electrolyte. Cost, safety and environmental impact were considered as well.
References:
[1] L. F. Arenas, C. Ponce de León, F. C. Walsh, J. Energy Storage
2017, 11, 119-153.
[2] R. Dmello, J. D. Milshtein, F. R. Brushett, K. C. Smith, J. Power Sources
2016, 330, 261-272.
[3] D. M. Cabral, P. C. Howlett, D. R. MacFarlane, Electrochim. Acta
2016, 220, 347-353.
[4] K. Xu, Chem. Rev. 2004,
104, 4303-4417.

Figure 1
Neutron Imaging at the ILL for Li-Ion Battery and Fuel Cell Research
Authors: Atkins Duncan 
Published: February 2020

NeXT-Grenoble is a Neutron and X-ray Tomography facility developed and now running in Grenoble, born from a collaboration between the University Grenoble Alpes and the European Neutron Source the Institut Laue-Langevin (ILL). This instrument combines the uniquely intense neutron flux offered by the ILL with laboratory X-ray tomography in order to obtain bi-modal imaging, thus taking advantage of the reciprocal benefits of each respective method.
As a preliminary step, a medium resolution neutron radiography/tomography instrument was implemented in 2016 allowing users to perform successful material characterisations in a wide range of applications such as Li-batteries, proton-exchange membrane fuel cells, porous/geomaterials and medical prosthetics. The specific transmission proprieties of neutrons (low attenuation of metals compared with relatively high absorption in light elements such as lithium and hydrogen, and isotopic differentiation, e.g., between 6Li and 7Li or 1H and 2H) and the high flux of ILL’s reactor is now enabling researchers to take this type of tomographic set-up to its limits in terms of the inherent compromise between temporal and spatial resolution.
In order to exploit the complimentarity of neutron and X-ray imaging, a laboratory X-ray ensemble has been integrated (see Figure 1) and is operational since 2018, along with an ensemble of high resolution neutron detectors. This has made possible for the first time full visualisation of in operando interactions between complex phenomena, notably in the domains of battery and hydrogen fuel cell research – examples of which will be shown here.

Figure 1
Investigating the Internal Processes of Thermo-Electrochemical Cells Using in-Situ Magnetic Resonance Imaging
Authors: Gunathilaka Isuru Eranda , Taheri Abuzar , Pringle Jennifer M , Forsyth Maria , O'Dell Luke 
Published: February 2020

Thermo-electrochemical cells are emerging as a promising and efficient method to convert waste heat to electricity. In addition to developing novel redox electrolyte materials to increase the energy densities, it is crucial for future developments to understand the internal chemical and thermodynamical processes happening inside the thermo-electrochemical cell while it is under operating conditions. Although the temperature and concentration distributions between the electrodes and the variations of the convection currents with cell orientation have been modelled mathematically, it has been a challenge to study these internal processes using experimental techniques.
Magnetic resonance imaging (MRI) is a non-invasive and well-established diagnosis technique in medical research to investigate physiology, but it also has the capability to study spatial properties of materials, chemical and thermodynamic processes in energy storage devices using different image contrast options including spin density, relaxation time and velocity [1]. The goals of this study are to develop an MRI method to study the internal chemical and thermodynamic processes within a functioning thermo-electrochemical cell, and understanding how these are affected by the electrolyte, the cell geometry and the orientation of the thermal gradient. A cobalt redox couple based electrolyte, which has been shown to be a promising candidate for thermo-electrochemical cells [2], was used for the in-situ experiments inside specialised cells custom built for MRI experiments, and temperature and concentration dependent 1H nuclear magnetic resonance spin-lattice relaxation time (T1) measurements were used to interpret the 1H T1 weighted MRI images of the working cells.

References

[1] Britton M. M., MRI of chemical reactions and processes, Progress in Nuclear Magnetic Resonance Spectroscopy, 101 (2017) 51-70.
[2] Dupont M. F., MacFarlane D. R., Pringle J. M., Thermo-electrochemical cells for waste heat harvesting – progress and perspectives, Chem. Commun., 53 (2017) 6288-6302.
High Voltage Window of the Symmetrical Electrochemical Capacitor Made By Using Dual Redox Additives Enhanced Quasi-Solid like Electrolyte
Authors: Chiu Chun-Kai , Yang Chih-Chieh , Kumar Amit , Pattanayak Bhaskar , Tseng Tseung-Yuen 
Published: February 2020

Recently, researchers have shown an increased interest in redox-active electrolyte because of its high performance and simple fabrication. However, most studies have only focused on aqueous electrolyte system, while suffering from limiting potential window of the electrochemical capacitor(EC) due to water decomposition voltage at 1.23 V. In addition, leakage problem results in safety concern in liquid system.
In the light of this, we introduce dual redox additives TEMPO and pBQ into PVDFHFP-BMIMTFSI-EC quasi-solid like polymer electrolyte (QSPE) as dual redox active electrolyte (RQSPE). The TEMPO and pBQ enable rapid charge transfer and highly solubility in ionic liquid, promoting the synergic effect of electric double layer capacitance(EDLC) and redox reaction. The coupling of battery-like reversible redox reaction and supercapacitor-like EDLC leads to provide high energy density and power density at the same time. The electrochemical properties of the fabricated EC involving RQSPE electrolyte and carbon electrodes are compared to those of the EC using QSPE without redox additives. The excellent specific energy of 61.12 Wh kg-1 is exhibited by the EC with RQSPE, which is over three times higher than the one without redox additives. In addition, the specific power density of the EC with RQSPE is up to 3.43 kW kg-1 at 17.10 Wh kg-1. Furthermore, the addition of redox additives can expand the voltage window of the EC to 3 V, while the EC without such additives has less value of 2.5 V. The ionic conductivity of the electrolyte is 8.85 mS cm-1, also indicating that adding redox additives have positive effect to the mobility of electrolyte. Finally, the EC with RQSPE exhibits stable cycling stability over 2000 charge/discharge cycles.

Figure 1
On Methanol Electrochemical Oxidation at Platinum-Bismuth Binary Catalyst
Authors: Alsaidi Walaa Saad , Awad Mohamed 
Published: February 2020

The electrochemical behavior of methanol on a binary catalyst composed of platinum and bismuth nanoparticles electrodeposited consecutively onto a pre- electro-activated glassy carbon electrode has been investigated. Either platinum was deposited first followed by bismuth or the reverse. The modified electrodes were morphologically characterized using scanning electron microscopy and their composition were probed using energy dispersive x-ray. The crystallography of the thus deposited nanoparticles was explored using XRD. Modified electrodes, i.e., Pt/Bi/GC (Bi deposited first) and Bi/Pt/GC electrodes (Pt deposited first) were electrochemically characterized using cyclic voltammetry and chronoamperometry.
It has been found that the electrocatalytic activity critically depends on the order of the deposition of platinum and bismuth. The Pt/Bi/GC electrode showed a larger electrocatalytic activity towards methanol oxidation compared to Bi/Pt/GC electrode. The higher activity obtained at the former electrode is attributed to the cooperative effect of Pt and Bi towards methanol oxidation.

Keywords: Platinum nanoparticles, bismuth, Electrodeposition, Methanol electro-oxidation.
Rapid Lab Grown Biofilm As a Tool for Engineering Sensor Networks of Biofouling-Resistant Electrochemical Sensors
Authors: Raditya Aldyla , O'Hare Danny 
Published: February 2020

Robust and rapid biofilm formation is not only a major interest in the development of microbial fuel cell, but it is also be of relevance to the development of indwelling environmental sensor networks. Sensor networks offer real-time, online and long-term monitoring which is an attractive monitoring strategy for water industry to prepare for increasing demand for clean water due to increased urbanisation and the pressures of climate change. Sensor networks support the development of robust and managed drinking water supply networks that are essential to human health.
Fouling of sensors due to biofilm formation is very common in indwelling situations and it is a major drawback in the development of sensor networks. Sensors will fail once it is fouled and it can happen in just a couple days or weeks. Engineering robust sensor networks begins with designing a biofouling resistant sensors. Electrochemical sensors are inexpensive and simple to construct and operate, and it is widely used in water industry. Understanding how biofilms affect electrochemical sensor performance is important to enable detection of malfunction in situ, and can inform the development of methodology to restore the performance in situ. Networks can consist of hundreds of sensors and automated restoration of function in biofouled sensors is thus essential.
Lab-based models play a vital role. However, it is not always possible to recreate the real conditions for biofilm formation in the lab and it can take too long for it to form. In a situation in which it is not possible to build a permanent testing setup, rapid lab grown biofilm is desirable.
Adhesion of pioneering bacterial cells to the surface is the most crucial step in biofilm formation. Adhesion of cells to surfaces can be accelerated by altering the surface chemistry of the surfaces. One way to do this is by plasma treatment of the surface. Formation of a lawn of biofilm is desirable to model early biofouling event. Polysaccharide production that forms the extrapolymeric substance (EPS) of biofilm can be induced by common biocidal substance such as triclosan. Electrochemically generated local concentration of hydrogen peroxide has similar consequences. In this work, we show that it is possible to form some coverage of biofilm on electrode surface in just two hours, which represents early biofouling event. It has a potential for the development of rapid lab grown biofilm that can be useful in developing fail-proof sensor networks.
Lattice Analysis By Synchrotron Powder Diffraction on High Voltage Spinel LiNi0.5Mn1.5O4
Authors: Seidel Matthias , Nikolowski Kristian , Auer Henry , Kinski Isabel , Wolter Mareike , Mikhailova Daria , Maletti Sebastian , Michaelis Alexander 
Published: February 2020

The high voltage spinel LiNi0.5Mn1.5O4 (LNMO) is a promising material to increase the energy density of lithium ion batteries. A variety of research was done to investigate the material regarding its properties, synthesis and commercial viability. To investigate in detail the properties of the cathode material during the delithiation and lithiation, in situ measurements are a helpful tool to fully understand changes in the crystal structure, which can give important information how to further improve the electrochemical properties of the cathode material. Especially the ‘ordered’ crystal phase P 4332 and the ‘unordered’ F d¯3
m, which can result from different temperature treatments during the synthesis process, need to be investigated to define the correlation between calcination temperatures, lattice parameters and electrochemical properties.
The LNMO investigated was synthesized using a spray drying method. From a solution of acetate and nitrate salts precursors were produced which have been calcined under different conditions to support the crystallization into the ordered and unordered phase, respectively. First, the two powders were characterised by SEM analysis to investigate the crystal morphology. Then slurries (LiNi0.5Mn1.5O4, PVDF binder, carbon, NMP solvent) were prepared and cast on aluminium foil to prepare electrodes. The electrochemical properties of assembled test cells (capacity, cycle life, etc.) were measured. Customized coin cells were used for the in situ measurements. The in situ XRD were measured using the high energy, low-emittance synchrotron radiation source at the Petra III beamline P02.1 at the DESY in Hamburg. 1

In our presentation we will correlate the synthesis temperatures, electrochemical properties and lattice parameters for the synthesized LNMOs. By deeply analysing the in situ measured diffraction patterns for the different state of charge we will fully demonstrate the phase transition for the different samples and correlate the lattice change to properties like the manganese(III) amount and the crystal phase (figure 1). The manganese(III) amount is mostly dependent on the calcination temperature and therefore also on the received crystal phase. Furthermore, we will outline the influence on the degradation for the different samples. The degradation differences between the synthesized samples were investigated by analysing the cumulative charge and discharge capacity. 2 The combination of those results will lead to a deeper understanding of the connection between the different influence factors for the cathode material.
References

A.-C. Dippel, N. Bindzus, D. Saha, J. T. Delitz, H.-P. Liermann, N. Wahlberg, J. Becker, E. D. Bøjesen and B. Brummerstedt Iversen, Z. Anorg. Allg. Chem.,
640(15), 3094–3099 (2014).

A. J. Smith, J. C. Burns, D. Xiong and J. R. Dahn, J. Electrochem. Soc.,
158(10), A1136 (2011).

Figure 1
Step Potential Electrochemical Spectroscopy (SPECS) As a Means of Examining the Behaviour of Electrochemical Systems
Authors: Donne Scott W 
Published: February 2020

Electrochemical energy storage and conversion devices play a substantial and growing role in society. The study of these systems has likewise continued to grow with significant efforst ongoing globally to develope new and improved materials and systems for consumer use. The basis of a significant proportion of this effort are fundamental material characteristics, as evaluated using a suite of physico-chemical and electrochemical characterization methods.
Electrochemically, characterization of such systems is typically based on techniques such as cyclic voltammetry and galvanostatic charge and discharge which provide a solid foundation for material and device performance evaluation. Of course the application of these methods to controlled electrodes allows for the initial characterization of electrochemical behaviour. Electrochemical impedance spectroscopy also plays a role in material and system characterization, albeit under very specific conditions.
Here we report on the application of an intermittent discharge and charge methodology, step potential electrochemical spectroscopy (SPECS), in particular its application to separating charge storage mechanisms in electrochemical systems, as well as its combination with additional electrodes and electrochemical techniques to elucidate behaviour.
Elemental Analysis of Aging Effects in Lithium Ion Batteries By Means of Laser Ablation-Inductively Coupled Mass Spectrometry
Authors: Harte Patrick , Mense Maximilian , Winter Martin , Nowak Sascha 
Published: February 2020

As the performance of the lithium ion battery (LIB) technology is rising constantly, one of the major challenge remains in the form complex aging phenomena, affecting crucial properties such as cycle life, capacity fade and safety.1 In order to improve the electrochemical performance of LIBs, by preventing or reducing aging effects, a deeper understanding of the degradation of battery materials and factors influencing these processes is needed.
Spatial and depth resolved elemental information allows for the study of different processes, such as transition metal dissolution (TMD) and subsequent deposition on the anode surface, as well as loss of active lithium (e.g. through deposition in the solid electrolyte interface (SEI), lithium plating).2 Established techniques for these investigations include time of flight-secondary ion mass spectrometry (ToF-SIMS) and Glow discharge-optical emission spectroscopy (GD-OES). However, small spot sizes, prolonged measurement times or the inability to provide spatial resolved information limit the applicability of these techniques. Laser ablation-inductively coupled mass spectrometry (LA-ICP-MS) offers the unique combination of spatial and depth resolved information, excellent limits of detection, fast measurement times (even for large samples) and easy sample preparation.
Therefore this work deals with the application of LA-ICP-MS as a direct solid sample analysis technique for the investigation of the degradation of LIB electrode materials. Mapping experiments are carried out to visualize deposition patterns of lithium and transition metals as well as study factors influencing these depositions.
(1) Vetter, J.; Novák, P.; Wagner, M. R.; Veit, C.; Möller, K. C.; Besenhard, J. O.; Winter, M.; Wohlfahrt-Mehrens, M.; Vogler, C.; Hammouche, A. Ageing Mechanisms in Lithium-Ion Batteries. J. Power Sources
2005, 147 (1–2), 269–281.
(2) Schwieters, T.; Evertz, M.; Fengler, A.; Börner, M.; Dagger, T.; Stenzel, Y.; Harte, P.; Winter, M.; Nowak, S. Visualizing Elemental Deposition Patterns on Carbonaceous Anodes from Lithium Ion Batteries: A Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry Study on Factors Influencing the Deposition of Lithium, Nickel, Manganese and Cobalt after Dissoluti. J. Power Sources
2018, 380 (January), 194–201.