bluuebunny/crossref_metadata_2025_split huggingface dataset:
Versatile Polymer-Template Method of Transition Metal Oxides for Lithium-Ion Battery Electrodes: Synthesis, Characterization and Electrochemical Properties
Authors: Lim Hyung-Seok , Suh Kyung-Do , Sun Yang-Kook 
Published: February 2020

Transition metal oxides have been studied as positive- and negative-electrode materials for high-energy lithium-ion batteries (LIBs). The performance of LIBs depends on the characteristics of active materials such as crystal structure, matter composition, morphologies and electrical properties because of the insertion/extraction kinetics of Li ions and electron transfer. In this study, we report the strategic synthesis methods of tailored active materials for high performance LIBs using external-stimuli responsive polymer particles. Since the three-dimensional cross-linked polymer spheres can accommodate the introduction of various metal ions and polar molecules by diffusion from the aqueous and non-aqueous solutions, the hierarchically structured hybrid metal oxide spheres can be synthesized easily. The medium pH is most important factor in determining the morphologies of metal oxide particles because the mesh size of the cross-linked polymer network and the size of the diffuse polar species depend greatly on the pH of medium. Besides, the polymer phase remains the carbon residues on the surface of primary metal oxide grains during calcination process at certain heating condition. These carbon residues can accommodate the volume variation of metal oxides reacted with lithium ions as well as increasing the electrical conductivity of electrodes. We have fabricated various kinds of transition metal oxide particles and also investigated their electrochemical performances as positive- and negative-electrodes for LIBs.
Monitoring Structural Changes in LixNi0.8Co0.15Al0.05O2 Using Ex Situ
7li/ 27al NMR
Authors: Trease Nicole M. , Seymour Ieuan David , Radin Maxwell , Liu Haodong , Hy Sunny , Chernova Natasha A. , Whittingham M. Stanley , Meng Ying Shirley , Van der Ven Anton , Grey Clare P. 
Published: February 2020

Although layered transition metal oxides are the most commercially available battery materials, they suffer from capacity fading over time due to transition metal (TM) and Li layer mixing that can lead to decreased Li diffusion and phase segregation due to oxygen loss. We have implemented 7Li and 27Al NMR to study the structural changes in LixNi0.8Co0.15Al0.05O2 (NCA) during electrochemical cycling. Using an optimized DFT calculated structure, the predicted NMR shifts are calculated using the spin-flipping method of Middlemiss et al.1 In the pristine materials, the 7Li and 27Al spectra indicate a dynamic Jahn-Teller distortion, as expected for LiNiO2, and the absence of Li in the TM layer. 27Al NMR also indicates that Al has a preference to be surrounded by six Ni3+ compared to a random solution model structure. 7Li NMR has been widely used to monitor local changes in the Li environment arising from Li/ TM layer mixing and the formation of defects and/or other phases. Here we show that the 27Al NMR shift of the Al environment is highly sensitive to its proximity to Ni3+, allowing for the indirect monitoring of Ni migration out of the TM layer after multiple cycles. Both 7Li and 27Al NMR can be utilized to indicate the mechanisms leading to capacity fade in NCA and other Al-substituted layered transition metal oxides over multiple cycles.
Reference
1. D. S. Middlemiss, A. J. Ilott, R. J. Clément, F. C. Strobridge and C. P. Grey, Chem Mater, 2013, 25, 1723-1734.
Insights into Microwave-Enhanced Cycling Performance of Nickel-Doped LiMn2O4 spinel Cathode Material at Elevated Temperature
Authors: Ozoemena Kenneth I. , Raju Kumar , Nkosi Funeka Phumzile , Mathe Mkhulu K. 
Published: February 2020

Lithium manganese oxide (LMO) is a state-of-the-art cathode material for lithium-ion batteries. LMO works well at ambient temperature; however, it undergoes rapid capacity-fading during cycling at elevated temperatures (~55 oC) due to the manganese-dissolution. The last two decades have witnessed a number of strategies reported in the literature (including patents) to mitigate this problem and allow the LMO for large-scale applications. Unfortunately, most of the proposed strategies are either time-consuming or involve extensive use of materials that add to the cost of the final product, and/or require the use of less environmentally-friendly chemicals including very harsh acids that must be handled with utmost caution. There is need therefore to explore the use of simpler, fast, less expensive and ‘greener’ synthesis strategy.
In our work, microwave-assisted solid-state reaction has been used to dope LMO with very low amount of nickel (i.e., LiNi0.2Mn1.8O4, herein abbreviated as LMNO) for lithium-ion battery from Mn3O4 prepared from electrolytic manganese oxide (EMD, g-MnO2). To establish the impact of microwave irradiation on the electrochemical cycling performance at elevated temperature (60 oC), the Mn3+ concentration in the pristine and microwave-treated LMNO samples was independently confirmed by XRD, XPS, 6LiMAS-NMR and electrochemical studies including electrochemical impedance spectroscopy (EIS). In this presentation, we will show that microwave-treated sample (LMNOmic) allowed for the clear exposure of the {111} facets of the spinel, optimized the Mn3+ content, promoting structural and cycle stability at elevated temperature. Importantly, at elevated temperature (60 oC), the LMNOmic gave an improved cycling stability (> 80% capacity retention and ca. 90 % coulombic efficiency after 100 consecutive cycling) compared to the LMNO. For the first time, the impact of microwave irradiation on tuning the average manganese redox state of the spinel material to enhance the cycling performance of the LiNi0.2Mn1.8O4 at elevated temperature and lithium-ion diffusion kinetics have been clearly demonstrated.
High Resolution, in Situ X-Ray Miscroscopy of Batteries
Authors: Weker Johanna Nelson , Wise Anna M , Toney Michael 
Published: February 2020

A fundamental component in the global move towards clean, renewable energy is the electrification of the automobile. Current battery technology limits electric vehicles to a short travel range, slow recharge, and costly price tag. Li-ion batteries promise the high specific capacity required to replace the internal combustion engine with a number of possible earth abundant electrode materials; however, setbacks such as capacity fading hinder the full capability of these rechargeable batteries. In the search for better electrode materials, high resolution chemical imaging during typical battery operation is vital in understand and overcoming the failure mechanisms of these materials.
By combining X-ray absorption spectroscopy with high resolution, hard X-ray transmission microscopy (TXM), we have tracked the chemical changes of electrode material in real time during typical battery operation.[1] We will discuss recent results tracking electrochemical and morphological changes in cathode materials during cycling. We will show dramatic chemical and morphological changes during a deep discharges (< 1V) of LiCoO2 and compare these to the changes seen during standard cycling and cycling above the 4.2 V limit consider “safe” for these materials. We have also tracked the Li-ion transport in LiFePO4 agglomerated during electrochemical cycling.[2] We observe spatially inhomogenous charging and discharging that do not correlated with agglomerate size. Finally, we will discuss how ptychography, an emerging X-ray microscopy technique that promises sub-5 nm resolution, has the potential to image batteries during cycling at resolutions that rival in situ TEM with liquid cells.
1. Nelson Weker, J. and M.F. Toney, Emerging In Situ and Operando Nanoscale X-Ray Imaging Techniques for Energy Storage Materials. Advanced Functional Materials, 2015. 25(11): p. 1622-1637.
2. Nelson Weker, J., et al., Tracking Non-Uniform Mesoscale Transport in LiFePO4 Agglomerates During Electrochemical Cycling. ChemElectroChem, 2015.
Cu-Based Ternary Fluorides As High-Energy Cathodes for Rechargeable Lithium Batteries
Authors: Wang Feng , Kim Sung-Wook , Graetz Jason 
Published: February 2020

Transition metal fluorides are promising for use as high-capacity cathodes in rechargeable lithium batteries for large-scale applications, such as electric vehicles and grid-scale storage, but energy-efficiency and kinetics related issues remain a major hurdle to their commercial use. Cu based fluorides are particularly attractive due to the intrinsic high redox potential and extraordinarily high specific energy density. Here we report on the synthesis, structural and electrochemical properties of new nanostructured ternary metal fluorides, which may overcome some of these issues. By substituting Cu into the Fe lattice, forming the solid solution CuyFe1-yF2, reversible Cu and Fe redox reactions were achieved with surprisingly small hysteresis (<150 mV). This finding indicates that cation substitution may provide a new pathway for tailoring electrochemical properties of conversion electrodes [1]. The Li storage/release mechanisms and limits to cycling stability of CuyFe1-yF2 were also investigated by combining electrochemical measurement with comprehensive structural and chemical analysis using in-situ X-ray absorption spectroscopy, X-ray diffraction, and transmission electron microscopy-electron energy loss spectroscopy (TEM-EELS). Detailed lithium reaction mechanisms, Cu-loss related issues along with possible remedy solutions in the CuyFe1-yF2 system, will be discussed. The work was supported as part of the NorthEastern Center for Chemical Energy Storage, an EFRC Center funded by the U.S. DOE-BES, under Award Number DESC0001294, and by DOE-EERE under the Advanced Battery Materials Research program, under Contract No. DE-SC0012704. [1] Wang et al., “Ternary Metal Fluorides as High-Energy Cathodes with Low Cycling Hysteresis”, Nat. Commun. 6: 6668 (2015).

Figure 1
Bulk and Interfacial Kinetics of Li1-XNi0.8Co0.15Al0.05O2 (NCA) Single Particles As a Function of State of Charge
Authors: Tsai Ping-chun , Wen Bohua , Yu Hui-Chia , Choe Min-Ju , Thornton Katsuyo , Chiang Yet-Ming 
Published: February 2020

At the length scale of electrode particles, interfacial reaction and/or bulk diffusion may determine rate-performance of lithium ion batteries (LIBs). In a conventional cell, in which electrodes are composed of active materials, binders, conductive agents, and current collectors, the mixtures of different materials result in a complex architecture, posing a great challenge to extract the intrinsic kinetic parameters of the electrode materials. In this work, we conduct single-particle experiments to directly measure the particle-level kinetics, and elucidate the rate-performance determining factors in LIBs. The scheme of our single-particle measurements is shown in Figure 1 [1]
Li1-xNi0.8Co0.15Al0.05O2 (NCA) is chosen as the model electrode material because of its extensive commercial utilization in LIB cathodes [2]. Here, for the first time, NCA single-particle kinetic parameters, including bulk diffusivity and exchange current density, at different states of charge (SOC) and particle sizes are systematically investigated using electrochemical impedance spectroscopy (EIS) and potentiostatic intermittent titration technique (PITT). Based on these obtained particle-level kinetic parameters, we will directly evaluate the relative kinetic contributions to overpotential at the particle level as a function of SOC and particle size, using Biot number analysis [3,4]. In coordination with the experiments, single-particle electrochemical simulations that take particle geometry, interface transport, and surface reactions into account are performed with EIS and PITT conditions. The synergic integration of experiments and simulations will examine and interpret the bulk and interfacial kinetics of NCA single particles. The dependence of these particle-level characteristics on other variables such as cathode composition, primary crystallite size, temperature, cycling history, and electrolyte composition will be discussed.

Acknowledgments

This work was supported as part of the North East Center for Chemical Energy Storage (NECCES), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award # DE-SC0012583. P-cT thanks the Ministry of Science and Technology, Taiwan (MOST 104-2917-I-006-006), for financial support.

References

[1] I. Uchida et al., J. Power Sources, 68, 139 (1997).
[2] R. Amin et al., J. Electrochem. Soc., 162, A1163 (2015).
[3] Juchuan, Li et al., J. Phys. Chem. C, 116, 1472 (2012).
[4] C. Montella et al., J. Electroanal. Chem., 518, 61 (2002).

Figure 1
Assessment of High-Energy and High-Power Graphite Anodes with Transmission Line Models
Authors: Weiss Michael , Ender Moses , Ivers-Tiffée Ellen 
Published: February 2020

Both, chemical composition and microstructure characteristics control the performance of electrodes for batteries. High-power and high-energy lithium ion batteries are composed of electrodes with similar or different chemical composition, but are always distinguishable by their electrode microstructure characteristics. But two-dimensional analysis methods like electron microscopy fail to quantify the key properties of different electrode microstructures.
X-ray tomography is best-suited [1] for three-dimensional anode reconstructions. This study investigates anodes removed from two consumer cells (1 Ah), namely a high-energy cell and a high-power cell.
Based on X-ray micro-CT reconstructions of the graphite anodes comprehensive sets of structural parameters are obtained. An in-depth analysis of (a) volume fractions, (b) surface areas, (c) particle size distributions and (d) tortuosity, gives insight into the different designs of the electrodes. Electrochemical impedance spectroscopy [2, 3] was performed and analyzed by the distribution of relaxation times (DRT) [4], enabling a separation of the several loss processes by their individual time constants. A transmission line model (TLM) [5] was set up assessing quantitatively the contribution of electronic and ionic transport in the porous electrode structure, as well as charge transfer and SEI resistance. Given the fact, that the effective ionic conductivity is 8 times smaller in the graphite anode of a high-energy cell, the contribution of lithium-ion transport through the electrolyte filled pores becomes significant for high currents.
References:
[1] M. Ender, J. Joos, A. Weber, E. Ivers-Tiffée, J. Power Sources 269 (2014) 912-919
[2] J. Illig, M. Ender, T. Chrobak, J.P. Schmidt, D. Klotz, E. Ivers-Tiffée, J. Electrochem. Soc. 159 (2012) A952-A960
[3] J. Illig, M. Ender, A. Weber, E. Ivers-Tiffée, J. Power Sources 282 (2015) 335-347
[4] H. Schichlein, A.C. Müller, M. Voigts, A. Krügel, E. Ivers-Tiffée, J. Appl. Electrochem. 32 (2002) 875-882
[5] J. Euler, W. Nonnenmacher, Electrochimica Acta 2 (1960) 268–286

Figure 1
Novel Additives for Improving Safety and Cyclability of Li-Ion Batteries
Authors: LO Jen Chih , Leu Chyi Ming , Yang Chang Rung , PAN Jing Pin , Lee Tzong Ming , SU Chun Wei 
Published: February 2020

Introduction

In recently, applicability of secondary batteries such as Li-ion batteries has been realized as power sources for portable electronic devices, electric vehicles (xEVs) and stationary power systems. Consequently, a strong need for the highly electrical performances of batteries due to increase in the capacity constituting a battery pack has grown. Among cell properties, cyclability and safety are the most critical issues for application. According to previous studies, cyclability could be affected by metal dissolution from cathode active material, lithium plating at low temperature or overcharge conditions, and properties of solid electrode interphase (SEI). Safety issues mainly results from internal or external short-circuit of batteries, caused by direct contact of cathode/anode, lithium dendrite penetration to separator, separator shrinks or meltdown, and so on.
At present investigation, we develop a composite additive (called TOC) comprising flouropolymer and clay particles. The TOC will form a continuous phase and simultaneously modify the anode surface. The effects of novel additives have been examined by SEM, electrochemical and safety analysis. Beyond the electrolyte additive and cell design, this research proposes another facile strategy via surface modification that provides excellent protection to improve the cyclability and safety in the meantime.

Results and Discussion

The surface morphology of active materials of MGP-A electrode that has been modified by TOC was analyzed by SEM. Generally, batteries which covered by polymeric layer display merely adequate performance of electricity. Such phenomenon results from hindering the lithium ion transportation between electrode and electrolyte while charging and discharging. Nevertheless, the results of cyclelife test at high temperature in Fig. 1, shows that battery with TOC additive possesses superior capacity retention after 300 cycles. The improvement of electrochemical properties could be attributed to not only the higher uptake of liquid electrolytes by the nanocomposites, but also facile the lithium transport by reducing interfacial resistance during charge and discharge.
Internal short-circuit (ISCr) plays a critical role in failure of batteries. Therefore, we simulate and examine the cell under ISCr condition through penetration test (Fig.2). The maximum temperature of TOC cell was merely 80°C, which is much lower than the pristine one (742°C). We suggest that the continuous film which formed by TOC additive have ability to protect the cell from directly contact of electrode while separator meltdown. Consequently, it prevents further ISCr and keeps battery safe.

Figure 1
Float Charging and Its Effects on Lithium-Ion Cells - What Can We Learn?
Authors: Swart Jan , Spray Ryan 
Published: February 2020

Typically aqueous based battery technology allows for float charging. Float charging is a charge condition where the battery is continuously charged at a low current level sufficient to not cause damage to the battery. Float charging is often used to balance the cells in a series string or “stack.” The premise is that lithium-ion batteries are a paradigm shift from aqueous based batteries due to their unique operating mechanism. The question “why is float charging not always desirable?” came about and testing and analysis was performed on batteries subjected to float charging over a three month period. The cells were evaluated at an electrode level using cell cross sectioning as well as optical and electron microscopy techniques. This presentation describes charge algorithms and also the observations obtained from the tests that were performed.
Characterization of Safety Aspects of Li-Ion Batteries for Maritime Applications
Authors: Forseth Sissel , Lian Torleif , Gilljam Martin , Weydahl Helge 
Published: February 2020

Electrical cars and consumer electronics use since several years back Li-ion batteries as electrical energy storage. This means that the Li-ion battery technology is mature enough for these applications. However, in maritime applications there are some issues to be solved, especially related to safety. The battery will be in a confined space and in many cases be much larger.
In addition to having high energy density, Li-ion batteries contain combustible material and most of the chemistries do also release oxygen[1] [2] [3]. Flammable gases such as hydrogen, carbon monoxide, methane, ethane etc. are also released up on heating[4]. Heating of the battery can be caused by internal flaws, e.g. particles from the cell production[5] and poor battery management design as well as external incidents such as fire.
In order to ensure a safe electrical/hybrid electrical power vessel, all data from electrical and safety tests (on cell and battery level) should be considered as a database of information. This information is vital to ensure a proper design of the battery and the battery room for the vessel in question. Included in the battery room design are the physical dimensions of the room and systems for mitigating the consequences of a battery vent, battery fire and possible gas explosion.
There are many factors that affect the safety of lithium-ion cells, such as chemistry, size, geometry and cell environments. Aging and cycling could also affect the safety properties. We have studied the thermal response of batteries during controlled heating (calorimetric techniques). Amongst the techniques used in our study is controlled heating by the use of an Accelerating Rate Calorimeter (ARC). In this case the size, geometry and cell environment have been kept constant, while different battery chemistries are varied.
The results obtained from the ARC tests on new 18650 cells show that the highest heat rate does not necessarily correspond to the most severe physical result. The results from aged and cycled cells will also be discussed.

[1] MacNeil, D.D. and J.R. Dahn, The Reaction of Charged Cathodes with Nonaqueous Solvents and Electrolytes: I. Li 0.5CoO2. Journal of The Electrochemical Society, 2001. 148(11): p. A1205.
[2] Arai, H., et al., Thermal Reactions Between Delithiated Lithium Nickelate and Electrolyte Solutions. Journal of The Electrochemical Society, 2002. 149(4): p. A401.
[3] Doughty, D.H., A general discussion of lithium ion battery safety, in The Electrochemical Society Interface. 2012. p. 37-44.
[4] Rothe, E.P. 19, s-l.: ESC Translations, 2008, Vol.11, pp.19-41. 10.1149/1.2897969
[5] Aircraft Incident Report, Auxiliary Power Unit Battery Fire Japan Airlines Boeing 787-8, JA829J, Boston, Massachusetts January , 2013, National Transportation Safety Board.
Performance of Lithium-Ion Battery When Operating in Radioactive and High Temperature Environment
Authors: Tan Chuting , Lyons Daniel Joseph , Zheng Yuan Fang , Co Anne C. , Cao Lei Raymond 
Published: February 2020

Lithium Ion Batteries (LIBs) are widely used in research, industry and households, especially equipped in autonomous systems, such as mobile robots in air, land, or sea. More importantly, some of the environments are filled with nuclear radiation and with high temperature. The performance of LIBs in these environments are crucial to sustained operations of these systems. Unfortunately, how an LIB may degrade the operation of such systems has not been seriously studied in the field. Researches on LIBs material, performance, sustainability, etc. have been done through recent decades. Many kinds of cathode, electrolyte and anode material have been discovered and several configurations, like coin cells, cylinder cells, and prismatic cells have been developed for different operating conditions. The concern is still on the performance degradation and reliability when operating in radiation and high temperature environments such as in outer space exploration, to power robots in hot cell, and equipment for performing rescue or sampling missions at post-nuclear accidents. In this study, we designed an in situ methodology to monitor LIBs performance degradation when operating (cycling) under gamma radiation with a post-accident dose rate (~30krad/h), in terms of capacity fade and impedance rise. Coin cells were assembled using commercial cathode material and electrolyte, with Li as reference electrode. An ex-situ irradiation -testing protocol was also adopted in this study, as we were interested in investigating separate radiation effects on individual battery components. Additionally, the effect of radiation on battery materials may be different at various temperature environment, for example, in space or in a nuclear accident field. We have conducted battery performance under irradiation while heating (80 °C) or cooling (-40 °C). Ex situ studies, including cathode material X-ray diffraction (XRD), and characterizations with Fourier Transform Infrared (FTIR) spectroscopy, ultraviolet–visible spectroscopy (UV-vis) spectroscopy and electron paramagnetic resonance (EPR) will also be discussed.