The electrochemical behavior of cells for 1/4, 1/3, 5/12, and 1/2 is reported. derived from or by substitution while maintaining all the remaining Mn atoms in oxidation state. Conventional wisdom suggests that lithium can be removed these materials only until both Ni states reach giving a charge capacity We show give smooth reversible voltage profiles reaching about 4.45 V when Li per formula unit are removed, as expected. If charged to higher voltages, surprisingly, they exhibit long...

The structure, synthesis, and electrochemical behavior of layered for 5/12, 1/2 are reported the first time. is derived from or by substitution while maintaining all remaining Mn atoms in 4+ oxidation state. with can deliver steady capacities 150 160 mAh/g at 30 55°C, respectively, between 3.0 4.4 V using a current density mA/g. Differential scanning calorimetry experiments on charged electrodes indicate that this material should be safer than cycled 2.0 4.6 to give about 200, 180, mAh/g,...

The synthesis, structure, and electrochemical performance of for is presented. prepared by substituting in while maintaining all the remaining Mn +4 oxidation state. Samples with 1/4, 1/3, 5/12, 1/2 have been investigated X-ray diffraction (XRD) neutron as well measurements. XRD patterns (0 < x ⩽ 1/2) show that these compounds adopt -type structure when synthesized at 800°C higher. also suggest a short-range superlattice ordering Li, Ni, transition-metal layer many samples. When 700°C lower,...

The electrochemical extraction and insertion of Na in was studied by situ X-ray diffraction. All the original can be extracted from it reversibly inserted again. When compound remains P2 structure. For a small amount O2-type stacking faults are introduced into electrode exists as two coexisting phases. These (with some faults) adopts O2 structure with faults. As sodium is reinserted to make forms evolution lattice parameters x constants also reported. © 2001 Electrochemical Society. rights reserved.

The structure and electrochemical behavior of with 3/8 is reported for the first time. prepared by simultaneous substitution in X-ray diffraction patterns show these materials have a layered -type structure. Both or can deliver stable capacity about 160 mAh/g between 2.5 4.4 V vs. Li using specific current 40 mA/g. If upper potential cells reduced to 4.2 Li, its retention improved it gives 136 mAh/g, which very close that same window. Studies thermal stability electrolyte differential...

SnO2 semiconductor nanoparticles were synthesized by an ultrasonic irradiation of aqueous solution SnCl4 and azodicarbonamide under ambient air. These are ∼3−5 nm in size, as calculated using the Debye−Scherrer formula, observed TEM. The also characterized powder X-ray diffraction (XRD), reflection spectroscopy FT-IR spectroscopy, transmission electron microscopy (TEM), DSC, TGA. band gap was from spectroscopy. Electrochemical tests performed electrode's materials nonaqueous Li salt...

Recently, there has been more and interest in charging to potentials above 4.2 V increase its specific capacity for commercial use. Unlike the situation below V, electrochemistry structure of is not completely clear. In this study, two reversible plateaus at 4.55 4.63 were observed voltage profile cells, which then studied by situ X-ray diffraction (XRD). The intermediate phase, formed 4.6 with was determined be a stage that lithium occupying only every second space between "sandwiches."...

Recent papers by Ammundsen et al. and Pan give evidence for the formation of local regions high in Mn content other Cr or Ni Li[Li0.2Cr0.4Mn0.4]O2 Li[Ni0.5Mn0.5]O2 EXAFS NMR methods, respectively. These observations are surprising following reasons: (1) each these materials is a part solid solution series, Li[CrxLi(1-x)/3Mn(2-2x)/3]O2 (0 < x 1) Li[NixLi1/3-2x/3Mn2/3-x/3]O2 1/2); (2) made at temperature, entropy considerations suggest that like transition-metal atoms should not cluster; (3)...

The intercalation of water into P2-Na2/3[CoxNi1/3-xMn2/3]O2 (x = 0, 1/6, 1/3) and T2 or O2 structure Li2/3[CoxNi1/3-xMn2/3]O2 has been investigated by X-ray diffraction thermogravimetric analysis (TGA). Water can be intercalated but not within P2-Na2/3[Ni1/3Mn2/3]O2. This difference may related to the existence superlattice ordering Ni atoms, Co transition metal layer which apparently induces a very strong interlayer interaction inhibits uptake water. Two water-containing phases...

<h3>BACKGROUND AND PURPOSE:</h3> MR fingerprinting allows rapid simultaneous quantification of T1 and T2 relaxation times. This study assessed the utility in differentiating common types adult intra-axial brain tumors. <h3>MATERIALS METHODS:</h3> acquisition was performed 31 patients with untreated tumors: 17 glioblastomas, 6 World Health Organization grade II lower gliomas, 8 metastases. T1, solid tumor, immediate peritumoral white matter, contralateral matter were summarized within each...

The solid solution series has been synthesized using a "sol-gel" method and studied by means of X-ray diffraction (XRD) electrochemical techniques. XRD results are used to infer that these samples isostructural except with their transition metal layers composed We believe the oxidation states elements in layer cells were made study changes voltage profiles composition, x. cell delivers reversible capacity about 130 mAh/g between 2.0 4.35 V vs. Li/Li+. Between 4.8 V, 230 via partial loss...

Na2/3Ni1/3Mn2/3O2 adopts a layered structure (P2) where the Ni and Mn cations form an ordered arrangement with √3a × superlattice. The superlattice is preserved in T2-structure Li2/3Ni1/3Mn2/3O2 prepared from Na-containing parent phase by ion exchange. In attempts to improve electrochemical properties of Li2/3Ni1/3Mn2/3O2, we have investigated effect Co substitution for phase. Using X-ray neutron diffraction, it shown that increasing amounts first weaken then suppress ordering transition...

LiNi1/3Mn1/3Co1/3−zMgzO2, LiNi1/3−zMn1/3Co1/3MgzO2, and LiNi1/3Mn1/3−zCo1/3MgzO2 (0≤ z ≤ 1/3) were prepared from hydroxide precursors. The precursors heated with Li2CO3 at 900 °C to prepare the oxides. Rietveld refinements of XRD data show that Mg substitution for Co, Ni Mn results in different degrees cation mixing Li layer very little most LiNi1/3Mn1/3Co1/3−zMgzO2. Electrochemical studies (0 samples used measure rate capacity reduction content, found be about −389 (mAh/g)/(z = 1)...

Lithium-rich layered Ni–Mn–Co oxide materials have been intensely studied in the past decade. Mn-rich serious voltage fade issues, and Ni-rich poor thermal stability readily oxidize organic carbonate electrolyte. Core–shell (CS) strategies that use material as core shell can balance pros cons of these a hybrid system. The lithium-rich CS introduced here show much improved overall electrochemical performance compared to core-only shell-only samples. Energy dispersive spectroscopy results...

Ultraviolet (UV) radiation poses risks to both human health and organics. In response the urgent demand for UV-shielding across various applications, extensive endeavors have been dedicated developing materials, spanning from wide-band gap semiconductors organo-inorganic composite films. However, existing UV shielding though suitable daily use, fall short of meeting demands extreme conditions. this work, we incorporated CeO₂ as a absorber into Y₂O₃...

Abstract As a vital vehicle part, the powertrain system is undergoing fast transition towards electrification. The new integrated electric drive has been widely used, especially for passenger cars. In this work, novel dual motor transmission proposed heavy commercial vehicles. scheme firstly introduced, which can achieve 9 different operating modes including 5 single and 4 modes. Then, mode shift map with minimum energy consumption designed based on efficiency management strategy. driving...

In this paper, it is demonstrated that all the lithium cannot be removed electrochemically from at room temperature below 5.4 V vs. On contrary, Na atoms can extracted and reinserted reversibly to form with Both of these results have been confirmed by X-ray diffraction measurements. Furthermore, when removed, adopts O2 structure random stacking faults. The pattern well matched simulations faults using DIFFaX program. Lithium inserted into however, only about one-half which removed. shows Li...

The structural evolution of during charge-discharge cycling is investigated by in situ and ex X-ray diffraction (XRD) methods. Rietveld refinements XRD patterns for taken the first extraction lithium show that transition metal atoms move to tetrahedral sites layers then octahedral layers. Although previous absorption near edge extended fine structure spectroscopy results showed migration Cr, they did not distinguish whether occupied Cr were located or measurements reported here process fully...

Li[Ni0.42Mn0.42Co0.16]O2/graphite pouch cells, with and without a LaPO4 coating on the positive electrode active material, containing additives prop-1-ene-1,3-sultone, 1,3,2-dioxathiolane-2,2-dioxide tris-(trimethyl-silyl) phosphite were studied using charge-hold-discharge cycling experiments up to potentials between 4.4 4.5 V at 40°C. Simultaneous electrochemical impedance spectroscopy measurements made during cycling. The effects of 24 hour hold top charge upper cutoff voltages 4.4, 4.425,...

The effect of Co substitution for Ni on the structure and electrochemical behavior has been investigated. It is found that can substitute to form solid solution which adopts P2 structure. When prepared by ion-exchanging Na in Li, T2 However, when exists an O2 with stacking faults. This occurs because additions gradually suppress superlattice ordering transition metals metal layers, destabilizes data indicate a small amount allows removal more lithium from lattice during first charge process...

The long-term cycling behavior of 24 promising electrolyte blends were systematically studied in LaPO4-coated Li(Ni0.4Mn0.4Co0.2)O2/graphite pouch type Li-ion cells tested to 4.5 V at 55°C. Capacity fade during cycling, charge-transfer resistance (Rct) before and after as well gas evolution formation also examined compared head-to-head. Of all the electrolytes tested, triallyl phosphate containing including 2% vinylene carbonate + 1 M LiPF6 sulfolane:ethyl methyl prop-1-ene sultone 1M...