The Experts below are selected from a list of 2958 Experts worldwide ranked by ideXlab platform
Khalil Amine - One of the best experts on this subject based on the ideXlab platform.
-
an organophosphine oxide redox shuttle additive that delivers long term Overcharge protection for 4 v lithium ion batteries
2015Co-Authors: Jinhua Huang, Larry A. Curtiss, Khalil Amine, Nancy Dietz L Rago, Nasim Azimi, Lei Cheng, Ilya A Shkrob, Zheng Xue, Junjie Zhang, Zhengcheng ZhangAbstract:Redox shuttle additives are used to protect Li-ion batteries from Overcharge. Increased operating voltage requires striking a balance between a high redox potential and electrochemical stability. 1,4-Bis[bis(1-methylethyl)phosphinyl]-2,5-dimethoxybenzene (BPDB) exhibits a redox potential of 4.5 V vs. Li/Li+ and provides stable Overcharge protection for 4 V cells delivering 95 cycles of 100% Overcharge ratio.
-
thermal and Overcharge abuse analysis of a redox shuttle for Overcharge protection of lifepo4
2014Co-Authors: Joshua Lamb, Zhengcheng Zhang, Khalil Amine, Lu Zhang, Christopher J Orendorff, Gregory Krumdick, Antoni S GozdzAbstract:Abstract This work investigated the performance and abuse tolerance of cells protected using the redox shuttle 1,4-bis(2-methoxyethoxy)-2,5-di-tert-butylbenzene. The thermal efficiencies were evaluated using isothermal battery calorimetry. Cells containing the Overcharge shuttle were observed to reach a steady state value of approximately 3.8 V, with a small variance in direct proportion to the applied current. In all cases the heat output from the cells was measured to reach ∼90% of the total input power. The heat output was also measured using isothermal calorimetry. At higher rates of Overcharge, the data shows that the cell containing the shuttle rapidly reaches a steady state voltage, while the temperature increases until a moderately high steady state temperature is reached. The control cell meanwhile rapidly increases in both applied voltage and cell temperature until cell failure. Two cells in series were taken deliberately out of balance individually, then charged as a single pack to observe the time needed to bring the cells into balance with one another.
-
in situ high energy x ray diffraction to study Overcharge abuse of 18650 size lithium ion battery
2013Co-Authors: Chikai Lin, Khalil Amine, Yang Ren, Yan Qin, Zonghai ChenAbstract:Abstract Overcharge is an aggressive abuse condition that can lead to thermal runaway of a lithium-ion cell. Understanding the failure mechanism due to Overcharge is critical for designing safer lithium-ion chemistries. With the help of in situ high-energy X-ray diffraction (XRD), we are able to detect the temperature difference between the cathode and the anode during the Overcharge abuse of 18650 cells. In this paper, the lattice constants of electrode current collectors (Al for the cathode and Cu for the anode) are calculated by fitting the XRD patterns, and the temperature variations of the cathode and anode are quantified by the thermal expansion of the Al and Cu foils. Based on these results, we report that during the Overcharge abuse of an 18650-size cell, using graphite as the anode and LiNi 0.8 Co 0.15 Al 0.05 O 2 as the cathode, the temperature of cathode increases as the voltage reaches 4.16 V, corresponding to the occurrence of the H2-to-H3 phase transition in the cathode material.
-
smart polymeric cathode material with intrinsic Overcharge protection based on a 2 5 di tert butyl 1 4 dimethoxybenzene core structure
2012Co-Authors: Wei Weng, Paul C Redfern, Larry A. Curtiss, Zhengcheng Zhang, Ali Abouimrane, Khalil AmineAbstract:Polymer-based electroactive materials have been studied and applied in energy storage systems as a valid replacement for transition metal oxides. As early as 1999, Hass et al. proposed an interesting concept on the possible incorporation of both charge storage and Overcharge protection functionality into a single material. However, there are virtually no examples of polymeric materials that can not only store the charge, but also consume the Overcharge current. Herein, a new material based on a cross-linked polymer (I) with 2,5-di-tert-butyl-1,4-dimethoxybenzene as the core structure is reported. The cyclic voltammogram of the synthesized polymer shows a single oxidation/reduction peak at 3.9–4.0 V. At 1C rate (56 mA/g), polymer I shows stable cycling up to 200 cycles with <10% capacity loss. The redox shuttle mechanism remarkably can be activated when cell voltage is elevated to 4.3 V and the Overcharge plateau at 4.2 V (2nd plateau) is persistent for more than 100 hours. The Overcharge protection was due to the release of a chemical redox shuttle species in the electrolyte during the initial charging process. Both DFT calculations and NMR analysis of the aromatic signals in the 1H-NMR spectrum of electrolytes from “Overcharged” cells provide evidence for this hypothesis.
-
Molecular engineering towards safer lithium-ion batteries: a highly stable and compatible redox shuttle for Overcharge protection
2012Co-Authors: Lu Zhang, Paul C Redfern, Larry A. Curtiss, Zhengcheng Zhang, Khalil AmineAbstract:Overcharge abuse is one of the most common and dangerous safety issues with state-of-the-art lithium-ion batteries. Thus, incorporation of Overcharge prevention into the lithium-ion battery pack is key to its practical application. Redox shuttle molecules that can be reversibly oxidized and reduced at specific potentials (redox potential) provide an effective and economic method to prevent Overcharge abuse for lithium-ion batteries. We have developed a novel oligo(ethylene glycol)-functionalized redox shuttle, 2,5-di-tert-butyl-1,4-bis(2-methoxyethoxy)benzene (DBBB), that is not only capable of providing efficient and long-lasting Overcharge protection to lithium-ion batteries (capable of withstanding over 180 cycles of 100% Overcharge at the C/2 rate), but is also compatible with the state-of-the-art lithium-ion cell system. Density functional theory calculations provided an understanding of the stability properties of this new redox shuttle.
Jie Jiang - One of the best experts on this subject based on the ideXlab platform.
-
weak cosmic censorship conjecture in einstein born infeld black holes
2019Co-Authors: Jie JiangAbstract:Recently, Sorce and Wald have suggested a new version of the gedanken experiments to overspin or Overcharge the Kerr-Newman black holes in Einstein-Maxwell gravity. Following their setup, in this paper, we investigate the weak cosmic censorship conjecture in the static Einstein-Born-Infeld black holes for the Einstein gravity coupled to nonlinear electrodynamics. First of all, we derive the first second order perturbation inequalities of the charged collision matter in the Einstein-Born-Infeld gravity based on the Iyer-Wald formalism as well as the null energy conditions of the matter fields and show that they share the same form as these in Einstein-Maxwell gravity. As a result, we find that the static Einstein-Born-Infeld black holes cannot be Overcharged under the second-order approximation after considering these inequalities. Our result at some level hints at the validity of the weak cosmic censorship conjecture for string theory.
J R Dahn - One of the best experts on this subject based on the ideXlab platform.
-
high potential redox shuttle for use in lithium ion batteries
2009Co-Authors: Lee Moshurchak, William M Lamanna, M Bulinski, Richard L Wang, Rita R Garsuch, Junwei Jiang, Douglas C Magnuson, Matthew Triemert, J R DahnAbstract:Redox shuttle additives can be used in lithium-ion cells to protect against overcharging and for cell balancing in multicell packs. Most previously reported redox shuttles have been either unstable as shuttles, resulting in a short duration of Overcharge protection, or have redox potentials that make them suitable only for cells containing lower potential positive electrode materials, such as LiFePO 4 . A new molecule, l,4-di-t-butyl-2,5-bis(2,2,2-trifluoroethoxy)benzene, is shown here to be a stable redox shuttle with a redox potential of 4.25 V and provides Overcharge protection in full Li-ion cells, implying adequate reductive stability. Experiments using Li/LiCoO 2 and Li/Li[Ni 1/3 Mn 1/3 Co 1/3 ]O 2 cells show that this molecule can work with high-energy-density positive electrodes as well as in full cells containing LiFePO 4 positive electrodes and Li, mesocarbon microbead, or Li 4 Ti 5 O 12 negative electrodes.
-
triphenylamines as a class of redox shuttle molecules for the Overcharge protection of lithium ion cells
2008Co-Authors: Lee Moshurchak, Claudia Buhrmester, J R DahnAbstract:The number of molecules that have been proposed as shuttle molecules has been steadily growing as research in the area continues. However, the number of molecules that provide lengthy Overcharge protection remains small. A class of molecules that provides better than average Overcharge protection in lithium-ion coin cells is the triphenylamine class. With the charge spread throughout the three aromatic rings and the central nitrogen, these molecules are stable and have a tuneable oxidation potential, as shown when electron-withdrawing bromines are added to the rings. The oxidation potential of triphenylamine is raised by approximately 0.11 V per bromine added. Also, the addition of bromine can increase the electrochemical stability of triphenylamine, as seen by an increased number of Overcharge cycles in coin cells containing tris(4-bromophenyl)amine instead of triphenylamine as the redox shuttle. This stability comes from the bromine preventing the formation of the dimer of triphenylamine, tetraphenylbenzidine.
-
phenothiazine molecules possible redox shuttle additives for chemical Overcharge and overdischarge protection for lithium ion batteries
2006Co-Authors: Claudia Buhrmester, Lee Moshurchak, Richard L Wang, J R DahnAbstract:The molecules 10-methylphenothiazine, 10-ethylphenothiazine. 3-chloro-10-methylphenothiazine, 10-isopropylphenothiazine, and 10-acetylphenothiazine are shown to be stable redox shuttle additives in LiFePO 4 /graphite and LiFePO 4 /Li 4 / 3 Ti 5 / 3 O 4 Li-ion coin cells to protect against Overcharge and overdischarge. The diffusion constant of 10-methylphenothiazine was measured using cyclic voltammetry to be 1.5 X 10 - 6 cm 2 /s, which translates to maximum shuttle-protected Overcharge current densities near 2 mA/cm 2 in practical cells. Although the redox potentials of these molecules (near 3.5 V) are somewhat low for LiFePO 4 , their stability over repeated Overcharge and overdischarge cycles is about equal to that of 2,5-di-tert-butyl-1,4-dimethoxybenzene that has been shown to provide protection for over 200 cycles of 100% Overcharge at C/10. Given the stability of these oxidized molecules, we believe that phenothiazine represents an attractive core for ligand substitution to adjust the redox potential to more practical values.
-
high rate Overcharge protection of lifepo4 based li ion cells using the redox shuttle additive 2 5 ditertbutyl 1 4 dimethoxybenzene
2005Co-Authors: J R Dahn, Lee Moshurchak, Junwei Jiang, M D Fleischauer, Claudia Buhrmester, L J KrauseAbstract:LiFePO 4 /Li 4 / 3 Ti 5 / 3 O 4 Li-ion cells have been investigated by many groups and their behavior in standard electrolytes such as 1 M LiPF 6 ethylene carbonate: diethyl carbonate (EC:DEC) is well known. Here we report on the behavior of these cells with 2,5-ditertbutyl-l,4-dimethoxybenzene added to the electrolyte as a redox shuttle additive to prevent Overcharge and overdischarge. We explore methods to increase the current-carrying capacity of the shuttle and explore the heating of practical cells during extended Overcharge. The solubility of 2,5-ditertbutyl-l,4-dimethoxybenzene was determined as a function of salt concentration in lithium bis-oxolatoborate-(LiBOB) and LiPF 6 -containing electrolytes based on propylene carbonate (PC), EC, DEC, and dimethyl carbonate (DMC) solvents. Concentrations of 2,5-ditertbutyl-l,4-dimethoxybenzene up to 0.4 M can be obtained in 0.5 M LiBOB PC:DEC (1:2 by volume). Coin-type test cells were tested for extended Overcharge protection using an electrolyte containing 0.2 M 2,5-ditertbutyl-1,4-dimethoxybenzene in 0.5 M LiBOB PC:DEC. Sustained Overcharge protection at a current density of 2.3 mA/cm 2 was possible and hundreds of 100% shuttle-protected Overcharge cycles were achieved at current densities of about 1 mA/cm 2 . The diffusion coefficient of the shuttle molecule in this electrolyte was determined to be 1.6 X 10 - 6 cm 2 /s from cyclic voltammetry and also from measurements of the shuttle potential vs. current density. The power produced during Overcharge was measured using isothermal microcalorimetry and found to be IV as expected, where I is the charging current and V is the cell terminal voltage during shuttle-protected Overcharge. Calculations of the temperature of 18650-sized Li-ion cells as a function of time during extended shuttle-protected Overcharge at various C-rates are presented. These show that Li-ion cells need external cooling during extended shuttle-protected Overcharge if currents exceed about C/5 rates.
Jianlin Li - One of the best experts on this subject based on the ideXlab platform.
-
effect of Overcharge on li ni0 5mn0 3co0 2 o2 graphite lithium ion cells with poly vinylidene fluoride binder i microstructural changes in the anode
2018Co-Authors: Nancy Dietz L Rago, Javier Bareno, Jianlin Li, Zhijia Du, David L Wood, Leigh Anna Marie Steele, Joshua Lamb, Scott Wilmer Spangler, Christopher Grosso, Kyle R FentonAbstract:Abstract Cells based on NMC/graphite, containing poly(vinylidene difluoride) (PVDF) binders in the positive and negative electrodes, were systematically Overcharged to 100, 120, 140, 160, 180, and 250% state-of-charge (SOC). At 250% SOC the cell vented. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) of the anodes showed several state-of-Overcharge-dependent trends. Starting at 120% SOC, dendrites appeared and increased in concentration as the SOC increased. Dendrite morphology appeared to be dependent on whether the active material was on the “dull” or “shiny” side of the copper collector. Significantly more delamination of the active material from the collector was seen on the “shiny” side of the collector particularly at 180 and 250% SOC. Transition metals were detected at 120% SOC and increased in concentration as the SOC increased. There was considerable spatial heterogeneity in the microstructures across each laminate with several regions displaying complex layered structures.
-
effect of Overcharge on li ni0 5mn0 3co0 2 o2 cathodes nmp soluble binder ii chemical changes in the anode
2018Co-Authors: Ira Bloom, Nancy Dietz L Rago, Javier Bareno, Zhijia Du, Fulya Dogan, Donald G Graczyk, Yifen Tsai, Seema R Naik, Yangping Sheng, Jianlin LiAbstract:Abstract Cells based on nickel manganese cobalt oxide (NMC)/graphite electrodes, which contained polyvinylidene difluoride (PVDF) binders in the electrodes, were systematically charged to 100, 120, 140, 160, 180, and 250% state of charge (SOC). Characterization of the anodes by inductively-coupled-plasma mass spectrometry (ICP-MS), X-ray photoelectron spectroscopy (XPS), and high-performance liquid chromatography coupled with electrospray ionization mass spectrometry (HPLC-ESI-MS) showed several extent-of-Overcharge-dependent trends. The concentrations (by wt) of nickel, manganese, and cobalt in the negative electrode increased with SOC, but the metals remained in the same ratio as that of the positive. Electrolyte reaction products, such as LiF:LiPO3, increased with Overcharge, as expected. Three organic products were found by HPLC-ESI-MS. From an analysis of the mass spectra, two of these compounds seem to be organophosphates, which were formed by the reaction of polymerized electrolyte decomposition products and PF3 or O=PF3. Their concentration tended to reach a constant ratio. The third was seen at 250% SOC only.
John M Connor - One of the best experts on this subject based on the ideXlab platform.
-
cartel Overcharges the author is professor emeritus at purdue university west lafayette in he is indebted to professor robert h lande who worked with the author on earlier law review articles on cartel Overcharges he also was responsible for locating
2014Co-Authors: John M ConnorAbstract:Abstract Many jurisdictions fine illegal cartels using penalty guidelines that presume an arbitrary 10% Overcharge. This article surveys more than 700 published economic studies and judicial decisions that contain 2,041 quantitative estimates of Overcharges of hard-core cartels. The primary findings are: (1) the median average long-run Overcharge for all types of cartels over all time periods is 23.0%; (2) the mean average is at least 49%; (3) Overcharges reached their zenith in 1891–1945 and have trended downward ever since; (4) 6% of the cartel episodes are zero; (5) median Overcharges of international-membership cartels are 38% higher than those of domestic cartels; (6) convicted cartels are on average 19% more effective at raising prices as unpunished cartels; (7) bid-rigging conduct displays 25% lower markups than price-fixing cartels; (8) contemporary cartels targeted by class actions have higher Overcharges; and (9) when cartels operate at peak effectiveness, price changes are 60–80% higher than the whole episode. Historical penalty guidelines aimed at optimally deterring cartels are likely to be too low.
-
cartel Overcharges survey and meta analysis
2006Co-Authors: John M Connor, Yuliya BolotovaAbstract:The article presents a unique regression analysis of social-science estimates of the size of cartel Overcharges. More than 800 Overcharge rates were collected from a variety of published sources that have appeared in the literature during the last 125 years. A meta-analysis of Overcharges from 395 cartel episodes finds that duration, legal environment, and organizational characteristics of cartels explain the variation on Overcharge rates to a greater extent than the type of publication or the method of Overcharge analysis. In particular, Overcharges are significantly higher for durable international cartels and are declining as antitrust enforcement regimes have stiffened. Historical case studies and government reports calculate lower Overcharges, whereas antitrust authorities arrive at relatively high rates.
-
the size of cartel Overcharges implications for u s and e u fining policies
2006Co-Authors: John M Connor, Robert H LandeAbstract:The purpose of this paper is to examine whether the current cartel fine levels of the European Union and the United States are at the optimal levels. The article does this by collecting and analyzing the available information concerning the size of the Overcharges caused by hard core pricing fixing, bid rigging, and market allocation agreements. Data sets for United States cartels are assembled and examined (these cartels Overcharged an average of 18% to 37%, depending upon the data set and methodology employed in the analysis and whether mean or median figures are used). Separate data sets for European cartels also are analyzed (which show Overcharges in the 28% to 54% range). The article similarly examines cartels that had effects solely within a single European country (which showed significantly lower Overcharges, averaging in the 16% to 48% range).In light of the antitrust objective of optimal deterrence, this article compares the current fine levels in both the European Union and the United States to the amounts gained on average by cartels as a result of their illegal activity. The results show that on average these cartel Overcharges are significantly larger than the criminal fines of either the European Union or the United States. This means that the United States and - especially - the European Union should increase their penalties for hard core collusion substantially.
-
our customers are our enemies the lysine cartel of 1992 1995
2001Co-Authors: John M ConnorAbstract:Prosecution of the lysine cartel signaled aresurgence in global price-fixingconspiracies in dozens of markets. It was the first to enter thevideo age and set new precedents for large criminal fines. Thispaper examines the sensitivity of Overcharges generated by thecartel to several factors: time period, seasonality of demand,and the price absent collusion. Civil settlements in the federalclass action (including the interrelated citric acid conspiracy)were the fourth highest in legal history. Yet, Overcharges of$65 to $134 million mean that buyers in the federal class receivedat most single damages. The opt-out firms got double damages.
-
ARCHER DANIELS MIDLAND:PRICE FIXER TO THE WORLD
2024Co-Authors: John M ConnorAbstract:Both market structure and corporate practices of Archer Daniels Midland fostered the implementation of the largest price-fixing conspiracies seen in modern times. The Overcharges imposed on U.S. buyers of lysine and citric acid during 1994-1995 by ADM and its co-conspirators amounted to at least $250 million, and the total amount of public penalties, private damages, and legal costs exceeds $666 million. Perpetrators of price-fixing now face monetary exposures that are five times the amount of the harm caused to buyers. These events have spurred renewed attention by U.S. antitrust authorities in prosecuting international cartels.Price fixing, lysine, citric acid, sweeteners, wet-corn milling, starch industry, Archer Daniels Midland, market structure, monopoly Overcharge, antitrust law, legal damages, U.S. Department of Justice.
