bluuebunny/crossref_metadata_2025_split huggingface dataset:
Crosslinked Gel Polymer Electrolytes with Different Li Salts for Electrochromic Cells
Authors: Han Taeyeong , Kim Seokwoo , Lee Hoogil , Ryou Myung-Hyun , Lee Yong Min 
Published: February 2020

The use of electrochromic windows to control heating and cooling loads in buildings and automobiles have attracted a lot of attention as a new and emerging strategy towards energy saving and energy storage to combat global warming and the energy crisis. The types of electrolyte salts employed in an electrochromic device is of great significance to the charge transfer which are in the form of ions between the electrodes. Thus, the electrolyte salt must be viewed as inert component of the electrochromic cell and it should be stable towards the cathode and anode. Hence, we conducted a comprehensive studies based on experiments on the effects of different salts in gel polymer electrolytes on the performance of electrochromic cells consisting of WO3/ITO as the working electrode and NiO/ITO as the counter electrode. Three different salts, 1M LiClO4, 1M LiFSI and 1M LiTFSI in propylene carbonate(PC)/polyethylene glycol diacrylate (PEGDA, Mn: 575) (7/3, v/v) were used in this study. Their ionic conductivities as well as the color changing behavior in the electrochromic cell were investigated.

Acknowledgements

This work was supported by the *Energy Technology Program of the Korea Institute of Energy Technology Evaluation and Planning(KETEP) granted financial resource from the Ministry of Trade, Industry & Energy, Republic of Korea (No. 20142010102980)

Figure 1
Ageing of Commercial 18650 Batteries Used in Tesla Model S Electric Vehicles
Authors: Uitz Marlena , Sternad Michael , Taeubert Corina , Traußnig Thomas , Hennige Volker , Wilkening Martin 
Published: February 2020

Li-ion batteries are attractive energy storage devices for years to come. They benefit from a high specific capacity combined with outstanding cyclability. In order to advance in conventional lithium-ion technology it is necessary to develop new materials and to improve existing concepts. In particular, the latter includes ageing studies on, e.g., commercially available batteries. Such studies help predict the lifetime of the batteries and assist in identifying the main failure mechanisms connected to lithium plating, passivating surface films, co-intercalation or dissolution of metal ions, for example.
In the present study commercial 18650 lithium-ion battery cells were used to perform fundamental cycle and calendar ageing studies. For this purpose systematic electro­chemical tests were carried out at three different temperatures, viz. – 25 °C, 40 °C and 60 °C. The cells were charged and discharged via galvanostatic cycling at different C rates ranging from 0.3 C to 1 C. For comparison, calendar ageing was electrochemically monitored at four different SOCs (100 %, 80 %, 50 % and 20 %). After the various aging steps the capacity fade and the increase in AC and DC impedance was determined.
It turned out that temperature has little effect on calendar ageing; the capacity fade (5 % at most) increases with increasing SOC. In contrast to this behavior, during cycle ageing temperature has a much larger effect on capacity fade and DC impedances. As an example, after 500 cycles at 25 °C (or 40 °C) the capacity fade is approximately 12 % of the initial value while at 60 °C the fade has reached already 22 %. DC impedances measured revealed the same trend. First post mortem analyses indicate that the ageing effects observed might be related to changes of the solid electrolyte interphase. Hence, the changes in electrochemical performance were correlated with the thickness and composition of the SEI formed. In particular, we quantitatively measured the formation of LiF via ion exchange chromatography. Interestingly, there is a clear interrelation between fluoride quantity in the SEI and DC impedance growth.
Design of Composite Electrodes with Anion-Absorbing Active Materials
Authors: Thomas-Alyea Karen E. , Aryanpour Masoud 
Published: February 2020

Organic radical polymers [1] and conjugated polymers provide exceptionally high rate capability when used as cathode materials for lithium-ion batteries. Upon charge (oxidation), these materials absorb anions from the electrolyte. In contrast, traditional inorganic cathode materials release lithium cations into the electrolyte during charge. All known negative electrode materials for lithium-ion batteries absorb lithium cations during charge. If a lithium-absorbing negative electrode is paired with a lithium-releasing positive electrode, then there is no net change in the salt content of the electrolyte (although there will be gradients in salt composition as lithium ions are transported from the anode to the cathode). However, salt content will decrease during charge of a cell with lithium-absorbing negative electrode and anion-absorbing positive electrode.
Most experimental results published to date [1] have used thin, highly porous cathodes in small flooded laboratory cells. Such cells have a large excess of electrolyte, so the effects of salt consumption have not been strongly evident. However, many important applications, such as electric vehicles and portable power, highly value both volumetric energy density and fast charge capability. These applications also want to minimize cell resistance, so the electrolyte composition is selected to maximize conductivity. Typical carbonate electrolytes show a maximum in conductivity between 1.0 and 1.1 M concentration of LiPF6 salt. In a conventional high-energy-density cell design, the salt needed for charging the organic-radical-polymer positive electrode would exceed the total salt content of such a typical electrolyte in the cell. Some [2,3] have explored composites of anion-absorbing active materials (eg polypyrrole or PTMA) with lithium-iron phosphate. However, even if the anion-absorbing material is limited to 10 volume% of the positive electrode, it will cause the overall cell salt content to decrease by > 0.6 M in practical high-energy cell designs.
Full-cell-sandwich simulations [4] can evaluate the impact of electrode design on the salt concentration distribution in the battery. Here we use a model that includes a composite positive electrode containing both inorganic lithium-releasing active material and organic anion-absorbing active material. The model is used to evaluate design tradeoffs for maximizing volumetric energy density.
References
[1] K. Oyaizu and H. Nishide, Polyradicals in Batteries. Encyclopedia of Radicals in Chemistry, Biology, and Materials, John Wiley & Sons Ltd: 2012, DOI 10.1002/9780470971253.rad083.
[2] A. Vlad, N. Singh, J. Rolland, S. Melinte, P. M. Ajayan, and J. F. Gohy, Scientific Reports 2014, DOI 10.1038/srep04315.
[3] Y.H. Huang and J. B. Goodenough, Chem. Mater. 2008, vol. 20#23 p. 7237.
[4] T. Fuller, C. M. Doyle, and J. Newman, J. Electrochem. Soc. 1994 vol. 141 p. 1; K. E. Thomas-Alyea, J. Newman, G. Chen, and T. J. Richardson, J. Electrochem. Soc. 2004 vol. 151 p. A509.
In Situ Studies of Oxide-Electrolyte Interface Reactivity in Lithium-Ion Batteries
Authors: Chen Xiao , Buchholz Donald Bruce , Stan Liliana , Feng Zhenxing , Fister Timothy T , Fenter Paul , Bedzyk Michael J. 
Published: February 2020

Li-ion batteries (LIBs) have been widely used in the past 2 decades, due to their higher energy density and cycling ability, typically using carbon as an anode and layered LiCoO2 as a cathode. The spinel, LiMn2O4 (LMO) is cheaper, safer, and more environmental friendly compared with widely-used LiCoO2 cathodes. However, LMO is known to lose capacity during cycling, ultimately due to disproportionation reactions of Mn3+ transforming to Mn2+ and Mn4+, and the subsequent dissolution of Mn2+ into the electrolyte. Yet our understanding of this process remains rudimentary, and we expect that it can be effectively addressed through interfacial modification (e.g., coatings). This work specifically focuses on developing and using a well-defined model system to observe these interfacial instabilities, and to develop suitable approaches to prevent it.
Recently, we have successfully grown high quality epitaxial LMO film on multiple substrates by pulsed laser deposition (PLD). Since LMO film itself is a poor electrical conductor, we have designed systems with built-in current collectors that maintains the LMO-substrate epitaxy. Multiple approaches have been investigated to make the whole system conductive and suitable for cycling: using conductive substrates, a conductive buffer layer, or a conductive surface coating. Conductive substrate is the most straightforward method. High quality epitaxial LMO film has been grown on Nb:STO. For the conductive buffer layer approach, we have tried many possible material including TiN, Al:ZnO, ITO, SrRuO3. It turns out that ITO and SrRuO3 are robust and enable oriented LMO deposition. Graphene was adopted as conductive surface coating. We have successfully transferred graphene onto the surface of LMO film using an anhydrous method.
We focus on the in situ real-time surface X-ray studies of well orientated LMO films in the standard lithium ion battery electrolytes (e.g., LiPF6 in EC/DMC). Using the high quality model films grown by PLD, we have probed the mobility of ions and interfacial atomic- and molecular- structures across the electrolyte/electrode interface, including the surface/interface structure changes and reconstruction (using XRR and CTR), individual processes of cation adsorption (resonant XRR/CTR), insertion/extraction.
Titanium Phosphite Ti2(HPO3)3, a New Negative Electrode Material for Lithium Ion Batteries
Authors: Lallaoui Abdelfettah , Edfouf Zineb , Benabdallah Omar , Abd-lefdil Mohammed , Saadoune Ismael , Cherkaoui El Moursli Fouzia 
Published: February 2020

Research in the area of solids open-framework metal phosphates, has been experiencing considerable growth over the past two decades. Since 1980s, a series of transition metal phosphates with three-dimensional structure have been investigated. More recently, it has been revealed that the phosphite group, could also be of great interest, because of its tendency to form new solids open framework structure.
In the literature, mixed-phosphite metal compounds have been widely synthesized with a variety of cations going from alkali metals to group IIIA of the periodic table. Some rare earth based phosphites have been also isolated. However, to the best of our knowledge, no compound with titanium and phosphite group has been reported. This compound has an interesting structure allowing it to be used as insertion material for electrodes of Li-ion batteries, while only phosphates and phosphides compounds have been used as electrode materials.
Recently, two inorganic phosphite materials were tested as electrodes for energy storage systems and have shown very small specific capacities toward lithium insertion [1,2]. Besides, both works dealt with the use of phosphite based-compound as positive electrode.
In this study, we are presenting a new titanium phosphite compound used as negative electrode material for lithium ion batteries. Ti2(HPO3)3 has been prepared under hydrothermal conditions and autogenous pressure. The structure of titanium phosphite with the determined crystallographic formula Ti2(HPO3)3 was solved in hexagonal system in centrosymmetric P63/m space group from single crystal diffraction data. The structure was solved by the direct method using, refined by full matrix least square.It has a three dimensional structure with tunnels along a- and b-axes (see figure). This is exactly what interests us to test it as an insertion electrode material.
This compound displays a high thermal stability limit showed by TGA analysis. Structural and chemical characterization have been realized by XRD, IR and Raman spectroscopies respectively. Electrochemical analyses were done by galvanostatic cycling and cyclic voltammetry. On the initial discharge of cell, the Ti2(HPO3)3 electrode delivers a capacity of 740 mAh/g.
In the aim of enhancing the electrochemical performances, Ti2(HPO3)3/graphene composite was also prepared via hydrothermal route. Results of both compounds will be presented and compared in this present publication.

[1] U. Chung, J.L. Mesa, J.L. Pizarro, I. de Meatza, M. Bengoechea, J. Rodríguez Fernandez, M. I. Arriortua, and T. Rojo, J. Chem. Mater. 23 (2011) 4317-4330.

[2] H. Yaghoobnejad Asl, K. Ghosh, M. P. Vidal Meza, A. Choudhurya, J. The Royal Society of Chemistry. (2013), 00, 1-3.

Figure 1
Co3V2O8 Sponge Network Morphology Derived from Metal-Organic Framework As an Excellent Lithium Storage Anode Material
Authors: Sambandam Balaji , Soundharrajan Vaiyapuri , Song Jinju , Kim Sungjin , Jo Jeonggeun , Kim Seokhun , Lee Seulgi , Mathew Vinod , Kim Jaekook 
Published: February 2020

Metal-organic framework (MOF) based synthesis of battery electrodes has presently become a hot topic of significant research interest. Considering the complications to prepare Co3V2O8 due to the criticality of its stoichiometric composition, we report here by a simple MOF formation by solvothermal technique followed by air annealing to synthesize Co3V2O8 for use as potential anodes for lithium battery applications. Structrual investigations by X-ray diffraction, X-ray photoelectron spectroscopy, high resolution electron microscopy, and surface area studies revealed that the phase pure Co3V2O8 nanoparticles are inter connected to form a sponge-like morphology with porous properties. Electrochemical measurements exposed the excellent lithium storage (~ 1000 mAhg-1 at 200 mAg-1) and retention properties (500 mAhg-1 at 1000 mAg-1 after 700 cycles) of the prepared Co3V2O8 electrode. A notable rate performance of 430 mAhg-1 at 3200 mAg-1 was also observed and ex-situ analysis confirmed the morphological and structural stability of this material after long cycles performance. These results validate that the unique nanostructured morphology arising from the use of the ordered array of MOF networks is favorable for improving the cyclability and rate capability in battery electrodes. The synthetic strategy presented herein may provide solutions to develop phase pure mixed metal oxides for high performance electrodes for useful energy storage applications.

Figure 1
CNT Branching on the 3D Nitrogen-Doped Graphene Architecture for Lithium Ion Battery
Authors: Park Beum Jin , Park Ho Seok 
Published: February 2020

The hybridization of 1D CNT with 3D graphene structure has recently attracted attention owing to their large specific surface area, high electronic conductivity, and structural integrity. These features of the hierarchical architectures can provide synergic affect on the energy storage such as supercapacitors, fuel cells and lithium-ion batteries. In addition, the performance has been further improved by doping with different heteroatoms like sulphur, boron, phosphorous and nitrogen because they can play a vital role in changing the local electronic density leading to improved electronic conductivity.
In this work, we synthesize 3D nitrogen (N)-doped reduced graphene oxide (rGO) branched by CNT for applications into lithium ion batteries. The hierarchical architecture consisting of the CNT branching on 3D N-doped rGO was characterized by SEM and TEM images. Iron oxide nanoparticles acted as the catalyst for the growth of CNT as well as active materials for lithium storage. The crystalline structure of iron oxide nanoparticles and restacking inhibition of rGO were confirmed by the XRD analysis. The BET data indicate the presence of mesoporous structure with average pore diameter of 21 nm with 400 m2/g surface area. The XPS data identified the presence, composition, and bonding configuration of carbon, iron, nitrogen and oxygen. The electrochemical properties were characterized by cyclic voltametry, impedance spectroscopy, and galvanic charge/discharge curve for lithium ion battery application.
Thermophysical Properties of Positive Electrode of Lithium-Ion Batteries
Authors: Saito Yoshiyasu , Kobayashi Hironori 
Published: February 2020

Thermal simulation is effective to estimate safety of lithium-ion batteries. For obtain reliable results by simulation, precise values are necessary for thermophysical properties such as specific heat capacity and thermal conductivity of the component materials of the batteries in wide temperature range. For the active electrode materials, since the lithium content varies during charge and discharge, dependency on state of charge (SOC) should also be considered. In this study, specific heat capacities and thermal conductivities of some positive electrode materials such as Li
x
Ni0.85Co0.05Al0.10 (NCA), Li
x
Ni1/3Mn1/3Co1/3O2 (NMC) and so on are studied as functions of temperature and lithium content. In addition, influence of electrode structure such as porosity is discussed for the thermal conductivity of the positive electrode.
The sample electrodes were prepared by coating the mixture of the active electrode material with carbon black and PVDF binder on both side of Al current collector of which thickness was 0.020 mm. The porosity and the thickness of the electrode were controlled by pressing.
The specific heat capacities of the samples were measured by the scanning method using differential scanning calorimeter. The thermal diffusivities of the electrode sheet were measured by the distance-variation method with a fixed modulation frequency in the periodic heating technique which is adequate for film-like samples. Then, the thermal conductivities were evaluated from the products of the specific heat capacities, the thermal diffusivities, and the bulk densities.
Additivity was confirmed for the specific heat capacity of the electrode sheet. The sample containing more lithium showed larger specific heat capacity except for crystal phase transition region. For the thermal conductivities, higher value was obtained from denser samples if the mixing ratio of active material, carbon black and PVDF was unity.
Battery Materials Exploration with Neutrons and Synchrotron X-Rays
Authors: Ren Yang , Sun Chenn-Jun , An Ke , Chen Zonghai , Xiao Xianghui , Aoun Bachir , Amine Khalil 
Published: February 2020

The increasing demands for alternative energy sources and energy storage systems have created a fast growing global market for rechargeable batteries. Extensive research activities are in progress worldwide aiming to develop reliable, cheap, environmentally benign and high-performance materials for advanced rechargeable batteries. Fundamental materials exploration is critical to achieve the next generation battery technology. X-rays and neutrons interact with matter in different ways, thus are frequently used as complementary tools for studying materials at the electronic, atomic and molecular levels. We have been utilizing synchrotron x-ray and neutron techniques to investigate a large variety of materials for energy applications. In this poster, we will present our recent results on both in-situ and ex-situ studies of battery materials using various neutrons and synchrotron x-ray techniques, including diffraction, imaging and spectroscopy. We will also discuss the challenges in battery materials research, and our future experimental approaches and computational modeling. (Use of the Advanced Photon Source was supported by the U.S. DOE Office of Science under Contract No. DE-AC02-06CH11357.)
In Situ Characterization of Gassing Processes in Lithium-Ion Batteries By Dems-Deirs
Authors: Berkes Balázs B. , Sommer Heino , Brezesinski Torsten , Janek Jürgen 
Published: February 2020

Gas evolution strongly affects the functioning of state of the art lithium ion batteries. On the one hand, it is the natural concomitant of SEI formation; on the other hand, because of the demand for high terminal voltages, it is the consequence of electrolyte or electrode material oxidation. This happens on the expense of the efficiency. Furthermore, the presence of gases in the cell raises safety problems.
Both the above mentioned gas formation processes are important to understand. First, to be able to develop novel electrolyte mixtures or tailor electrolyte additives that form a stable SEI. Second, to optimize the surface and/or structure of the cathode materials to influence their bulk oxidative properties upon delithiation and electrocatalytic activities.
Herein, we present results on the in situ gas analysis by means of differential electrochemical mass spectrometry and infrared spectroscopy (DEMS-DEIRS) of various battery systems. We analyse the SEI formation on different anode materials and the influence of various electrolyte additives. The impact of temperature and constant voltage/OCV periods on the first charge cycle (so-called formation process) is investigated. Their effect on both the gassing and electrolyte salt decomposition is described.
The stability problem of the most common electrolytes at high voltages is discussed. These are achieved either with NMC (LiNixMnyCozO2) type materials or with high voltage spinels (LiNi0.5Mn1.5O4). Beyond the decomposition of the electrolyte, oxygen evolution is the crucial factor at high cathode potentials. This effect is particularly apparent for overlithiated and high Ni content materials that will be presented as well. Monitoring gassing over 20 cycles reveals interesting changes in its characteristic being only recognizable in long term tests. We demonstrate the importance of potentiodynamic cycling tests beneath the traditional galvanostatic ones with DEMS-DEIRS in the exploration of reaction mechanisms. Pressure measurements complete the analysis in terms of validation of gas amounts and supplement them with three-electrode long term investigations.
Dopamine As an Electrolyte Additive for Lithium Secondary Batteries
Authors: Lee Hoogil , Han Taeyeong , Kim Seokwoo , Jin Dahee , Kim Hee Joong , Rho Jin Woo , Ryou Myung-Hyun , Lee Yong Min 
Published: February 2020

Polydopamine is gaining much interest in lithium secondary batteries (LSBs) due to its ability to enhance the electrochemical characteristics of the various LSB systems. However, the commercialization of polydopamine is being delayed due to long production time. Nevertheless, recent studies have showed that polydopamine can be formed during galvanostatic charge and discharge of unit cells with dopamine. Hence we adopt this methodology to study the effects of dopamine as an electrolyte additive on the electrochemical performance of LSBs. The effect of the dopamine additive is characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and electrochemical impedance spectroscopy (EIS). The cycle performance of coin cells containing dopamine in the electrolyte at different temperatures are examined by changing cut-off voltages together.
The coin cells having 0.1 wt.% of dopamine exhibited an enhanced cycle performance at both high voltage (3.0~4.5V vs. Li/Li+, 25oC, C/2 rate) and elevated temperature (3.0~4.3V vs. Li/Li+, 55oC, C/2 rate). The improvement in the cycling performance is attributed to the suppression of transition metal dissolution in the cathode as well as the decomposition of both solvent and salt in the electrolyte due to the formation of the polydopamine on the surface of the cathode during the galvanostatic charge and discharge.
Acknowledgements

This work was supported by the Human Resource Training Program for Regional Innovation and Creativity through the Ministry of Education and National Research Foundation of Korea (NRF-2014H1C1A1066977) and by the Sebang Global Battery.
Refernces

1. M.-H. Ryou, Y. M. Lee, J. K. Park, and J. W. Choi, Advanced Materials 2011, 23, 3066-3070.
2. Y. Lee, M.-H. Ryou, M. Seo, J. W. Choi, Y. M. Lee, Electrochimica Acta 2013, 113, 433–438.
3. T. Lee, Y. Lee, M.-H. Ryou, Y. M. Lee, RSC Advances 2015, 5, 39392-39398
4. K. Kang, S. Lee, R. Kim, I. S. Choi, and Y. Nam, Angewandte Chemie International Edition 2012, 51, 13101 –13104.