bluuebunny/crossref_metadata_2025_split huggingface dataset:
Long Duration Studies of Lithium Battery Materials Using Synchrotron X-Ray Powder Diffration
Authors: Baker Annabelle , Day Sarah , Tang Chiu C. 
Published: February 2020

The use of in-situ X-Ray Powder diffraction for the study of new battery materials has grown in recent years, providing an insight into the effects that charge/discharges cycles have on cathode materials. These experiments are often limited to short periods of time and therefore only allow for one full charge/discharge cycle/multiple fast cycles to be observed. The result is that material characteristics may be well understood for the first cycle but little is known about the long term processes that ultimately lead to failure of the cell over longer timescales.
The Long Duration Experiment (LDE) Facility on Beamline I11 at Diamond Light Source is the first of its kind, housing experiments that require periodic, in-situ monitoring over periods of months to years. It is an ideal facility for the long term study of battery materials, allowing data to be collected over many cycles. To conduct these experiments a new cell had to be developed that would allow the transmission of X-rays, while also remaining impermeable to air and moisture for a long period of time. Previous in-situ diffraction experiments of battery materials have generally involved using unconventional cells. While these are effective, they are often not stable for long periods of time and are not true representations of real-life battery systems. By modifying a standard CR2032 coin cell case, we have been able to produce a cell that fits this purpose. Laser thinning was used to reduce the thickness of a small section of the cell to 50μm, allowing sufficient X-ray transmission without compromising the integrity of the cell.
Compton Scattering Imaging for Operando Observation of Battery Cell
Authors: Itou Masayoshi , Sakurai Yoshiharu , Suzuki Kosuke , Sakurai Hiroshi , Orikasa Yuki , Uchimoto Yoshiharu 
Published: February 2020

We propose an X-ray Compton scattering imaging technique based on synchrotron radiations for observation of lithium migration and internal structure change in battery cells under in-situ and operation conditions.
This technique uses high-energy monochromatic X-rays as the probe, and detects Compton scattered X-rays from a certain volume element inside a battery cell. Because the energies of both X-rays are higher than 100 keV with high penetration power, it is possible to observe the inside of battery cells. The intensity of Compton scattered X-rays is proportional to electron density and the energy profile of Compton scattered X-rays provides the electron momentum density distribution, both of which enable us to analyze the internal structure and lithium concentration inside the battery cell. In this presentation, we demonstrate the capability of the X-ray Compton scattering technique by visualizing both the migration of lithium ions in the positive electrode and the structural change due to the volume expansion of the electrode [1, 2].
This work was supported by Japan Science and Technology Agency.
[1] K. Suzuki et. al., J. Appl. Phys. 119, 025103 (2016)
[2] M. Itou et .al., J Synchrotron Radiat. 22, 161-4 (2015)
In-Operando Imaging of Electrodeposition and Dendrites Using Nanoscale X-Ray Computed Tomography
Authors: Choi Paul , Kedlaya Vinayak , Mandal Pratiti , Frisco Sarah , Whitacre Jay , Litster Shawn 
Published: February 2020

The widespread implementation of lithium-ion batteries in systems ranging from portable electronics to electric vehicles has generated a remarkable demand for batteries with improved durability and performance. In order to satisfy said demand, the issue of dendrite formation must be addressed; dendrite growths inside batteries have been observed to create an internal short circuit that results in catastrophic failure.1 Consequently, dendrite propagation not only poses a significant safety hazard to existing lithium-ion batteries, but also is detrimental to the development of next-generation lithium based energy storage technologies such as lithium-air batteries. A better understanding of dendrite nucleation and growth behavior through direct visualization is crucial to developing effective dendrite mitigation techniques. Prior studies observed these phenomena using electron microscopy2 and micro-scale resolution X-ray computed tomography (micro-CT).3,4 These approaches present distinct challenges, including the vacuum environment of electron microscopes2,5 and insufficient resolution of micro-CT to image nucleation events.3

An interesting alternative is the use of the nano-scale resolution X-ray CT (nano-CT) that allows for three-dimensional observations within opaque materials at high resolution (50 nm) with any electrolyte with controlled environmental conditions. In this study, an in-operando cell for nano-CT imaging was designed and fabricated, in which the working electrode is prepared on a metal wire placed within electrolyte contained by a sealed capillary. This work addresses the particular challenges of preparing in-operando electrochemical cells for lab-scale nano-CT instruments, which include sealing, limited cell size, and the beam path length through the sample. Additional considerations include the development of high temporal resolution 4D (3D plus time) reconstruction algorithms to address the longer exposure times of lab-scale instruments. Preliminary experiments demonstrating these capabilities include the imaging of dendritic copper electrodeposition using copper wires and aqueous copper sulfate electrolyte. Figure 1 shows the images of the in-operando copper dendrite growth acquired using the nano-CT with a 65 mm field of view and an exposure time of 10 s. The results in Figure 1f show that following the initial cell transient, the cell current increases with the corresponding increased surface area of the dendrites.

References

1. P. G. Balakrishnan, R. Ramesh, and T. Prem Kumar, J. Power Sources, 155, 401–414 (2006)
2. J. K. Stark, Y. Ding, and P. A. Kohl, J. Electrochem. Soc., 160, D337–D342 (2013)
3. K. J. Harry, D. T. Hallinan, D. Y. Parkinson, A. A. MacDowell, and N. P. Balsara, Nat. Mater., 13, 69–73 (2014)
4. D. S. Eastwood et al., Chem. Commun. (Camb)., 51, 266–8 (2015)
5. W. Xu et al., Energy Environ. Sci., 7, 513–537 (2014)

Figure 1
EIS Analysis of Commercial Lithium-Ion Battery on Accelerated Degradation for Long-Term Charge-Discharge Cycling
Authors: Mukoyama Daikichi , Nara Hiroki , Yokoshima Tokihiko , Momma Toshiyuki , Osaka Tetsuya 
Published: February 2020

A lifetime of batteries is one of the most important issues for energy storage systems. Non-destructive measurement methods are demanded on accelerated testing in the development of a lithium ion battery (LIB) for longer lifetime, in order to provide shortening development period and reducing development cost. Electrochemical impedance spectroscopy (EIS) is the effective method of non-destructive investigation for batteries. We already proposed an equivalent circuit for a wide range of impedance spectra. [1,2]The electrochemical impedance of the electrodes in a commercial LIB at various states was analyzed to evaluate by this circuit. In this study, we focused on an analysis of accelerated degradation of the LIB for the long term charge-discharge cycling.
A commercially available pouched LIB with a nominal capacity of 5 Ah for an electric assist bicycle was used in this work. The batteries were charged and discharged with a constant current (CC) protocol between 3.0 and 4.2 V with a rate of 2 C at 25 °C and 45 °C. The discharge capacities of LIBs were measured with a rate of 1/3 C at 25 °C. The impedance of the batteries was measured by Biologic VMP3 with AC signal amplitude of 0.4 A in the frequency range from 100 kHz to 10 mHz at 25 °C. Before the impedance measurement, the batteries were charged at a rate of 1/3 C to 4.2 V, and were maintained for 3 h.
During continuous charge-discharge cycling of LIB under 25 °C and 45 °C, the discharge capacities gradually decrease to less than 65% after 9,700 cycles and 2,400 cycles, respectively (Fig. 1). The variety of frequency responses accompanying the capacity degradation at 25 °C is shown in Fig. 2 (a). The frequency responses at 10 mHz increased with charge-discharge cycles, EIS analysis using equivalent circuits imply that the major factor of LIB degradation is the active material degradation of the cathode. On the other hand, frequency responses accompanying the capacity degradation at 45 °C showed the almost same increase tendency in Fig. 2 (b). We will present the EIS analysis using equivalent circuit on accelerated testing with charge-discharge cycles in detail.
This work was partly supported by “Research & Development Initiative for Scientific Innovation of New Generation Batteries” and “Development of Safety and Cost Competitive Energy Storage System for Renewable Energy” from NEDO, Japan.
References:

T. Osaka, et al., J. Power Sources, 205 (2012) 483-486.

D. Mukoyama, et al., Chem. Lett., 41 (2012) 444-446.

Figure 1
An Inverse Model of Acoustics in Batteries for Determining Structural Changes, State of Charge and State of Health
Authors: Davies Greg , Hsieh Andrew , Steingart Daniel A 
Published: February 2020

There has been recent interest in using acoustic techniques as a diagnostic tool for batteries. Studies have shown that significant changes in the acoustic fingerprints of batteries occurs during cycling [1,2]. These shifts can be correlated with electrochemical and physical phenomena within the cell. Ideally, the goal is to determine battery properties based on the acoustic fingerprint of a cell without a prior understanding of the state of health or charge of the cell. Furthermore, we would seek to understand acoustic behaviour as cells degrade or approach catastrophic failure. Here we present modeling developed to understand acoustic and electrochemical interactions in a cell. A forward model of a cell subject to acoustic signals is presented, which captures some critical characteristics of the system. Then, an associated inverse method is presented, which seeks to back out critical material characteristics relevant to cell state of charge, state of health and potential failure modes.
1. A. G. Hsieh et al., Energy Environ. Sci., 8, 1569–1577 (2015).
2. S. Bhadra, A. G. Hsieh, M. J. Wang, B. J. Hertzberg, and D. A. Steingart, J. Electrochem. Soc., 163, A1050–A1056 (2016).
Electrodeposition As an Approach for Fabricating High Performance Battery Electrodes
Authors: Marschilok Amy C , Takeuchi Kenneth J , Takeuchi Esther S 
Published: February 2020

Conventionally, battery electrodes are prepared from physical mixtures of conductive additives, polymeric binders, and electroactive active material particles which are usually coated onto metal foil current collectors. The three passive components serve distinct functions, where the current collector provides structural support, the binder maintains physical adhesion throughout the composite, and the conductive additives establish an interconnected conduction network. Minimizing the mass of passive material in the electrode is desirable to maximize functional gravimetric capacity. To maximize energy density and rate capability, obtaining a continuous conductive pathway with open pores for fast ion transport is critical.
Electrodeposition is presented here as a design strategy for lightweight, high performing, high energy density battery electrodes. Opportunity for removal or reduction of passive components will be discussed. Examples of direct deposition of electroactive particles onto a three-dimensional, lightweight, conductive substrate will be described, along with functional testing of the resulting composite electrodes for beyond lithium-ion batteries (i.e. magnesium-ion batteries and metal air batteries). Benefits of the electrodeposition based fabrication strategy, including quantitative control over active material loading, and opportunity to realize continuous electrical contact by design, will be highlighted.
Mechanical Properties of Electrodeposited Al-W Alloy Films and the Effects of Subsequent Heat Treatment
Authors: Higashino Shota , Takahashi Ayumu , Kasada Ryuta , Miyake Masao , Hirato Tetsuji 
Published: February 2020

Due to their high oxidation and corrosion resistance, Al coatings are effective in extending the lifetimes of other metallic materials. However, the low mechanical strength of Al can limit its adoption for certain applications. Alloying Al with other transition metals, which improves the mechanical properties, can be a possible solution to this problem.
Electrodeposition is a simple method of forming Al-base alloy films from ionic liquids represented by EMIC-AlCl3. Among the Al-base alloys, Al-W alloy is of significant interest since it is expected to exhibit excellent mechanical properties. The electrodeposition of Al-W alloys from EMIC-AlCl3 baths containing K3W2Cl9 was reported previously[1]. However, Al-W alloys electrodeposited from this system had a powdery morphology when the W content was >7 at.%, and the mechanical properties have not been investigated.
In this study, we report the electrodeposition of Al-W alloy films from EMIC-AlCl3 baths containing WCl2. Nano-indentation tests were undertaken to determine the hardness and Young’s modulus of the Al-W alloy films. The effects of heat treatment on the mechanical properties were also examined.
It was possible to electrodeposit Al-W alloy films containing up to 12 at.% W. XRD patterns showed that these films were fcc solid solution at low W contents, and were amorphous at 12 at.% W. The hardness increased from 1.8 GPa with increasing W content. The film containing 12 at.% W showed the highest hardness value of 4.6 GPa, which is close to that of pure bulk W. The Young’s modulus also increased from 97 to 168 GPa with increasing W content in the solid solution range, followed by a sudden decrease to 89 GPa at 12 at.% W. This value is close to that of pure bulk Al. The low Young’s modulus of Al-12 at.% W alloy is attributed to its amorphous structure. Heat treatment at 300-400°C for 3 h was carried out. After the heat treatment at 400°C, Al-W intermetallic compounds were detectable by XRD, and both the hardness and Young’s modulus increased.
These results show that Al-W alloy films with excellent mechanical properties can be obtained from EMIC-AlCl3-WCl2baths. In particular, amorphous Al-12 at.% W films displayed interesting properties, including hardness values as high as that of W and Young’s modulus values as low as that of Al. The hardness and Young’s modulus of Al-W films can be controlled by modifying the W content and conducting subsequent heat-treatment.
[1] T. Tsuda et al., Journal of the Electrochemical Society 161, D405-D412 (2014)
Gradient Morphologies in Electrodeposited Manganese Dioixde and Their Effect on Electrochemical Performance
Authors: Donne Scott W , Fellows Hannah , Beyad Yaser 
Published: February 2020

In this study, the use of current and potential control techniques in production of electrolytic manganese dioxide (EMD) has led to insight into the behaviour of different morphologies of manganese dioxide for a number of chemical storage systems. Further, improvements on industrial milling have been considered. Manganese dioxide has an advantage of existing in a variety of phases, and it has been found that current density greatly influences crystal structure along with deposit densities. Through the manipulation of this factor during the depositing of EMD a variety of morphologically different deposits can be obtained, linking to advantages for a number of industrial applications.
Techniques such as chronopotentiometry and chronoamperometry have allowed for insight into the application of step potential ramps, multilayer depositions, and the manipulation of pulse sequences in a series of EMD deposits to be morphologically investigated through techniques such as scanning electron microscope (SEM) and X-ray diffraction (XRD) along with electrochemical performance testing.
The objective of this study has been to provide a real world application, and superior performance essentially allowing for an alternative to bulk depositing. The study has considered specialised purposes such as industrial milling i.e. improving fracturing capabilities along with battery/capacitor applications with these deposits aiming to highlight the importance of improved electrolyte transport with regard to cathode interaction.
On the Dynamics of Solid Oxide Fuel Cell Stacks: Preliminary Model-Driven Design and Control
Authors: Boigues Muñoz Carlos , Abate Lorenzo , McPhail Stephen J. 
Published: February 2020

The inexorable inclusion of high temperature fuel cells in the energy grid of the world’s major economies accentuates the needs for more robust systems capable of tolerating non-stationary conditions with minor degradation. It seems undeniable that the latter needs to be addressed mainly by basic and applied research on the fuel cell stack components (electrodes, interconnects, etc…), yet there is still space for performance improvement by optimising system integration.
This paper encompasses the experimental procedure used to fully characterise a 6-cell intermediate temperature solid oxide fuel cell (IT-SOFC) short stack when operating in non-stationary conditions and in dissimilar load demands, fuel flows, fuel utilisations and temperatures, simulating to some extent a real-life appliance capable of following electrical load and/or heat demand. The spanning of such input factors allows generating a space-matrix of variables – voltages, temperatures and output gas compositions – that describe the system’s dynamic and stationary performance considering null degradation. This experimental approach can produce appropriate values so as to generate simple autoregressive models suitable for real-time one-step-ahead predictions of the output variables. In this work, the most effective mathematical correlation between the numerous inputs and outputs resulted to be a non-linear autoregressive exogenous (ARX) model built by means of a treepartition algorithm (i.e. binary search trees). The normalised root mean square error (NRMSE) of the calculated fit of the train data was above 94% in all of the cases denoting that the model simulates exceptionally well the system’s outputs in the studied ranges.
Additionally, the model was validated with test data, more particularly a dynamic current-voltage curve, and the results show how the simulated points follow remarkably well the experimental results. It must be noted that the electrical current imposed to the SOFC stack in the test data ranged from 5A to 20A, which is the range in which the model performs best; nevertheless outside these bounds the model is capable of simulating exceptionally well the voltage output, especially at high current densities.
This dynamic model can be of great use for preliminary design & control of power plants incorporating nominal size stacks from the same manufacturer/integrator by increasing the understanding of how the plant will perform when in transient conditions. Furthermore, the present model is capable of assessing online the degradation rate of a fuel cell stack by comparing the experimental results with the expected ones from the model.
Electrochemical Behaviour of Industrial IrO2-Ta2O5 Anodes for Copper Electrowinning
Authors: Xu Wenting , Haarberg Geir Martin , Sunde Svein , Seland Frode , Ratvik Arne petter , Zimmerman Erik , Åkre Torjus 
Published: February 2020

Lead-based anodes are widely used in copper electrowinning (EW). However, lead can induce contamination of the electrolyte during copper EW due to the corrosion of the anode [1]. Furthermore, corrosion while at high current densities will finally lead to the failure of the anode since the overvoltage for oxygen evolution reaction (OER) on lead is still rather high, and the service life of lead-based anodes is quite limited in industrial copper plants [2]. Besides, lead and lead compounds are toxic, which means the use of lead-based anodes is not environmentally friendly. Dimensionally stable anodes (DSAs) with IrO2-Ta2O5 oxides coated on titanium substrates hold excellent electrocatalytic activity and electrochemical stability, and have the most potential to replace lead-based anode in copper EW industry.
In this work, different types of commercially available electrode samples with IrO2-Ta2O5 coating were studied. The studies focused on investigating the impact of surface microstructure on electrocatalytic activity. Surface morphology and chemical composition of DSA samples were analyzed using scanning electron microscopy (SEM, Hitachi S-3400N) combined with energy dispersive spectroscopy (EDS). X-ray diffraction (XRD) studies were carried out using Bruker AXS D8Advance with grazing incident angle at 3°. The crystalline structure and phase composition were analyzed by varying the 2θ angle from 10° to 80°. The electrochemical experiments were carried out in aqueous solution with 0.9 M H2SO4 and 1.2 M CuSO4. A Teflon holder giving a 1 cm2 electrode surface area was used. All experiments were conducted at 60 °C. Cyclic voltammetry (CV) measurements were recorded in a range between 0.55 V and 1.35 V vs. SHE with varying sweep rate from 300 mV/s to 1 mV/s. The scan rate for all polarization measurement was 0.5 mV/s. The ohmic (IR) drop during the testing was corrected for by measuring the electrolyte resistance using electrochemical impedance spectroscopy (EIS) at high frequency. Electrocatalytic activity for anodes as a function of composition and preparation method was determined by steady state polarization analysis. The durability of the anodes was investigated by accelerated lifetime tests, which were carried out in 0.9 M H2SO4 solution at the constant current density of 2 A/cm2.
In the present work, commercial DSAs were used instead of samples fabricated in the laboratory. This offers not only valuable results for DSAs research but also a consideration for DSAs manufacturers to improve the quality of the DSA.

[1] M. Clancy, C. J. Bettles, A. Stuart, N. Birbilis, Corrosion behaviour and catalytic effectiveness of Pb–Ca–Sn, RuO2 –IrO2 /Ti and IrO2 –Ta2O5/Ti anodes for copper electrowinning, Hydrometallurgy 131-132 (2013) 144.
[2] G. N. Martelli, R. Ornelas, G. Faita, Deactivation mechanisms of oxygen evolving anodes at high current densities, Electrochim. Acta 39 (1994) 1551.
A Generalized Numerical Method for Approximating Equilibrium Reactions for Electrochemistry Simulations
Authors: Lange Kyle , Goldin Graham , Lueth Chris , Walchshofer Christian , Makridis Alexandros 
Published: February 2020

Many electrochemistry applications such as wet-etching, flow-batteries and electroless deposition involve equilibrium reactions, chemical reactions which instantaneously reach an equilibrium state. The equilibrium state is defined by the equilibrium constant which specifies an algebraic constraint on the molar concentrations of participating species in the reactions. The simulation of electrochemistry applications which involve both ion transport and equilibrium reactions is particularly challenging because the system of equations is over-constrained.
Previous approaches for solving this combined set of reaction / transport equations have involved equation substitution or solving combinations of equations along with elemental conservation. The resulting implementations have been specific for particular problems and are difficult to implement for the most general case. In this work, we present a new algorithm which can be generalized for any set of equations and provides an efficient, approximate solution for both ion transport equations and equilibrium chemistry. Example validation results are provided along with a discussion of the limitations of the approach.