The Experts below are selected from a list of 24723 Experts worldwide ranked by ideXlab platform
Arumugam Manthiram - One of the best experts on this subject based on the ideXlab platform.
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a mg doped high nickel layered Oxide Cathode enabling safer high energy density li ion batteries
Chemistry of Materials, 2019Co-Authors: Qiang Xie, Arumugam ManthiramAbstract:High-nickel layered Oxide Cathodes with a Ni content of >90% show substantial potential for next-generation lithium-ion batteries (LIBs) due to their high capacity and lower cost. However, they are plagued by rapid capacity decay and poor thermal stability, which hamper their practical viability. We present here Li0.98Mg0.02Ni0.94Co0.06O2 (NC-Mg) with 2% Mg doping, aiming to provide a strategic guideline for solving the issues. The Mg2+ ions occupy the lithium layer and are proposed to act as pillar ions, which substantially enhance the structural reversibility and reduce the anisotropic lattice distortion upon cycling, thereby greatly improving the electrochemical and thermal stability of NC-Mg compared to the undoped LiNi0.94Co0.06O2 (NC). Specifically, NC-Mg delivers 214 mA h g–1 with a capacity retention of 80.1% after 500 cycles in pouch-type full cells, much higher than the retention of NC (56.3%). A discharge capacity of 158 mA h g–1 at 10C rate demonstrates its remarkable rate capability. Addition...
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A Mg-Doped High-Nickel Layered Oxide Cathode Enabling Safer, High-Energy-Density Li-Ion Batteries
2019Co-Authors: Qiang Xie, Arumugam ManthiramAbstract:High-nickel layered Oxide Cathodes with a Ni content of >90% show substantial potential for next-generation lithium-ion batteries (LIBs) due to their high capacity and lower cost. However, they are plagued by rapid capacity decay and poor thermal stability, which hamper their practical viability. We present here Li0.98Mg0.02Ni0.94Co0.06O2 (NC-Mg) with 2% Mg doping, aiming to provide a strategic guideline for solving the issues. The Mg2+ ions occupy the lithium layer and are proposed to act as pillar ions, which substantially enhance the structural reversibility and reduce the anisotropic lattice distortion upon cycling, thereby greatly improving the electrochemical and thermal stability of NC-Mg compared to the undoped LiNi0.94Co0.06O2 (NC). Specifically, NC-Mg delivers 214 mA h g–1 with a capacity retention of 80.1% after 500 cycles in pouch-type full cells, much higher than the retention of NC (56.3%). A discharge capacity of 158 mA h g–1 at 10C rate demonstrates its remarkable rate capability. Additionally, the Mg doping significantly elevates the exothermic peak temperature of NC-Mg to 211 °C, in sharp contrast to 177 °C for NC, highlighting the improved thermal stability of NC-Mg. Collectively, the superior performance of NC-Mg demonstrates a feasible alternative strategy for developing safer, high-energy-density LIBs
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long life nickel rich layered Oxide Cathodes with a uniform li2zro3 surface coating for lithium ion batteries
ACS Applied Materials & Interfaces, 2017Co-Authors: Bohang Song, Wangda Li, Seungmin Oh, Arumugam ManthiramAbstract:As nickel-rich layered Oxide Cathodes start to attract worldwide interest for the next-generation lithium-ion batteries, their long-term cyclability in full cells remains a challenge for electric vehicles. Here we report a long-life Ni-rich layered Oxide Cathode (LiNi0.7Co0.15Mn0.15O2) with a uniform surface coating of the Cathode particles with Li2ZrO3. A pouch-type full cell fabricated with the Li2ZrO3-coated Cathode and a graphite anode displays 73.3% capacity retention after 1500 cycles at a C/3 rate. The Li2ZrO3 coating has been optimized by a systematic study with different synthesis approaches, annealing temperatures, and coating amounts. The complex relationship among the coating conditions, uniformity, and morphology of the coating layer and their impacts on the electrochemical properties are discussed in detail.
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smart design of lithium rich layered Oxide Cathode compositions with suppressed voltage decay
Journal of Materials Chemistry, 2014Co-Authors: Eun Sung Lee, Arumugam ManthiramAbstract:The lithium-rich layered Oxide Cathodes offer a high capacity of ∼250 mA h g−1, but their commercialization is prevented by the problem of voltage decay during cycling, originating from a phase transformation to a 3 V spinel-like phase. With an aim of understanding the factors that govern the voltage decay, the effect of the length of the plateau region during first charge and the octahedral-site stabilization energy of the transition metal (TM) ions has been investigated by designing various compositions of lithium-rich layered Oxides. Charge–discharge profile and dQ/dV plot variations during cycling confirm that the length of the plateau region during first charge is the primary governing factor in the voltage decay process. The voltage decay is enhanced by a lengthened plateau region that increases the kinetics of the phase transformation to the spinel-like phase due to the (i) formation of Litet–V(TM)Li–Litet dumbbells (Litet refers to the lithium ion in a tetrahedral site and V(TM)Li refers to the lithium-ion vacancy in the TM layer) because of the increased lithium-ion extraction from the TM layer and (ii) TM migration to the lithium layer assisted by a higher oxygen vacancy concentration. Based on this understanding, a new series of compositions Li1.2−xMn0.54Ni0.13+2xCo0.13−xO2 have been designed to minimize the plateau region during first charge without sacrificing the energy density. The optimized composition Li1.15Mn0.54Ni0.23Co0.08O2 exhibits superior electrochemical performance with a marked decrease in voltage decay during cycling compared to the well-known composition Li1.2Mn0.54Ni0.13Co0.13O2.
Gerbrand Ceder - One of the best experts on this subject based on the ideXlab platform.
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fluorination of lithium excess transition metal Oxide Cathode materials
Advanced Energy Materials, 2018Co-Authors: William D Richards, Stephen Dacek, Daniil A Kitchaev, Gerbrand CederAbstract:Fluorination of Li-ion Cathode materials is of significant interest as it is claimed to lead to significant improvements in long-term reversible capacity. However, the mechanism by which LiF incorporates and improves performance remains uncertain. Indeed, recent evidence suggests that fluorine is often present as a coating layer rather than incorporated into the bulk of the material. In this work, first-principles calculations are used to investigate the thermodynamics of fluorination in transition metal Oxide Cathodes to determine the conditions under which bulk fluorination is possible. It is found that unlike classic well-ordered Cathodes, which cannot incorporate fluorine, disordered rock salt-structured materials achieve significant fluorination levels due to the presence of locally metal-poor, lithium-rich environments that are highly preferred for fluorine. As well as explaining the fluorination process in known materials, this finding is encouraging for the development of new disordered rock salt lithium-excess transition metal Oxides, a promising new class of Li-ion battery Cathode materials that offer superior practical capacity to traditional layered Oxides. In particular, it is found that bulk fluorination may serve as an alternative source of Li-excess in these compounds that can replace the conventional substitution of a heavy redox-inactive element on the transition metal sublattice.
Xueliang Sun - One of the best experts on this subject based on the ideXlab platform.
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highly stable ni rich layered Oxide Cathode enabled by a thick protective layer with bio tissue structure
Energy Storage Materials, 2020Co-Authors: Meng Liu, Biwei Xiao, Yang Jiang, Huan Lin, Zhenggang Zhang, Guoxin Chen, Qian Sun, Feng Huang, Xueliang Sun, Deyu WangAbstract:Abstract Ni-rich layered Oxide (LiNixMnyCozO2 (NMC), x > 60%), one of the most promising Cathode materials for high-energy lithium ion batteries (LIBs), still suffers from surface instability even with the state-of-art protective coatings, which normally are limited to ≤10 nm to maintain the required kinetics. Here we demonstrate a highly conductive protective layer with bio-tissue structure that can enable high-rate operation of NMC Cathodes even with a thickness exceeding 40 nm. With this thick protection layer, the modified LiNi0.8Mn0.1Co0.1O2 (NMC811) Cathode retains 90.1% and 88.3% of its initial capacity after 1000 cycles in coin cells and pouch cells, respectively. This novel membrane is composed of crystalline nano-domains surrounded by ~1 nm amorphous phase, which is an effective distance to enable tunneling of electrons and Li+ ions between these domains. The coated NMC811 Cathode releases ~55.3% less heat under thermal abuse and largely enhances his safety feature during puncture test. The coating also enables excellent electrochemical stability of NMC811 even after it was exposed to a moist environment for four weeks at 55 °C, which is critical for large-scale production of high-energy-density LIBs.
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oxygen containing functional groups enhancing electrochemical performance of porous reduced graphene Oxide Cathode in lithium ion batteries
Electrochimica Acta, 2015Co-Authors: Dongbin Xiong, Xueliang Sun, Hui Shan, Yang Zhao, Lei Dong, Xianfa ZhangAbstract:Abstract Exploring high performance and environment-friendly electrode materials is highly desirable for the sustainable Li-ion batteries (LIBs) system. In this study, a facile approach of the modified Hummers’ method combining with special thermal reduction was proposed to synthesize nanostructured reduced graphene Oxide (RGO) with abundant oxygen-containing functional groups. The resultant RGO showed high specific capacity and excellent cyclability as Cathode materials for LIBs. The specific capacity of about 220 mAh g−1 at a current density of 50 mA g−1 was achieved after 100 cycles. More importantly, it was demonstrated that the capacity increased with the increase of the amount of oxygen functional groups, highlighting the significant effects of oxygen-containing functional groups of RGO on high lithium storage performance.
Khalil Amine - One of the best experts on this subject based on the ideXlab platform.
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unveiling decaying mechanism through quantitative structure activity relationship in electrolytes for lithium ion batteries
Nano Energy, 2021Co-Authors: Rachid Amine, Khalil Amine, Zonghai Chen, Tomas Rojas, Lei Cheng, Anh T NgoAbstract:Abstract Understanding the decaying mechanism in lithium-ion batteries (LIBs) is critical to establishing a stable electrolyte system. Despite the advent of various novel electrolyte solvents designated for high-voltage LIBs, their working principles are not fully understood. Currently, oxidative decomposition of electrolytes is believed to be the major cause of capacity fade, and tremendous effort has been devoted to discovering a new electrolyte with enhanced anodic stability. However, the oxidative decomposition process cannot solely explain the rapid decay of some electrolyte systems with intrinsic high anodic stability when used with a high-nickel layered Oxide Cathode such as LiNi0.6Mn0.2Co0.2O2 (NMC622). In this report, a study of the quantitative structure-activity relationship was conducted to deepen the mechanistic understanding of the decay in high-voltage LIBs. The results obtained from the newly introduced molecular pair analysis and linear free-energy relationship (LFER) studies were highly consistent with the solvation-involved decaying mechanism in a high-nickel layered Oxide Cathode cycling at high voltage (> 4.5 V vs. Li/Li+). There was no evidence correlating the solvation ability of electrolyte solvents with the decay of a high-nickel layered Oxide Cathode cycling at a relatively low voltage (
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conflicting roles of nickel in controlling Cathode performance in lithium ion batteries
Nano Letters, 2012Co-Authors: Ilias Belharouak, Khalil Amine, Dapeng Wang, Guangwen Zhou, A Genc, Zhiguo Wang, Fei Gao, Suntharampillai Thevuthasan, Donald R Baer, Jiguang ZhangAbstract:A variety of approaches are being made to enhance the performance of lithium ion batteries. Incorporating multivalence transition-metal ions into metal Oxide Cathodes has been identified as an essential approach to achieve the necessary high voltage and high capacity. However, the fundamental mechanism that limits their power rate and cycling stability remains unclear. The power rate strongly depends on the lithium ion drift speed in the Cathode. Crystallographically, these transition-metal-based Cathodes frequently have a layered structure. In the classic wisdom, it is accepted that lithium ion travels swiftly within the layers moving out/in of the Cathode during the charge/discharge. Here, we report the unexpected discovery of a thermodynamically driven, yet kinetically controlled, surface modification in the widely explored lithium nickel manganese Oxide Cathode material, which may inhibit the battery charge/discharge rate. We found that during Cathode synthesis and processing before electrochemical cy...
Qiang Xie - One of the best experts on this subject based on the ideXlab platform.
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a mg doped high nickel layered Oxide Cathode enabling safer high energy density li ion batteries
Chemistry of Materials, 2019Co-Authors: Qiang Xie, Arumugam ManthiramAbstract:High-nickel layered Oxide Cathodes with a Ni content of >90% show substantial potential for next-generation lithium-ion batteries (LIBs) due to their high capacity and lower cost. However, they are plagued by rapid capacity decay and poor thermal stability, which hamper their practical viability. We present here Li0.98Mg0.02Ni0.94Co0.06O2 (NC-Mg) with 2% Mg doping, aiming to provide a strategic guideline for solving the issues. The Mg2+ ions occupy the lithium layer and are proposed to act as pillar ions, which substantially enhance the structural reversibility and reduce the anisotropic lattice distortion upon cycling, thereby greatly improving the electrochemical and thermal stability of NC-Mg compared to the undoped LiNi0.94Co0.06O2 (NC). Specifically, NC-Mg delivers 214 mA h g–1 with a capacity retention of 80.1% after 500 cycles in pouch-type full cells, much higher than the retention of NC (56.3%). A discharge capacity of 158 mA h g–1 at 10C rate demonstrates its remarkable rate capability. Addition...
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A Mg-Doped High-Nickel Layered Oxide Cathode Enabling Safer, High-Energy-Density Li-Ion Batteries
2019Co-Authors: Qiang Xie, Arumugam ManthiramAbstract:High-nickel layered Oxide Cathodes with a Ni content of >90% show substantial potential for next-generation lithium-ion batteries (LIBs) due to their high capacity and lower cost. However, they are plagued by rapid capacity decay and poor thermal stability, which hamper their practical viability. We present here Li0.98Mg0.02Ni0.94Co0.06O2 (NC-Mg) with 2% Mg doping, aiming to provide a strategic guideline for solving the issues. The Mg2+ ions occupy the lithium layer and are proposed to act as pillar ions, which substantially enhance the structural reversibility and reduce the anisotropic lattice distortion upon cycling, thereby greatly improving the electrochemical and thermal stability of NC-Mg compared to the undoped LiNi0.94Co0.06O2 (NC). Specifically, NC-Mg delivers 214 mA h g–1 with a capacity retention of 80.1% after 500 cycles in pouch-type full cells, much higher than the retention of NC (56.3%). A discharge capacity of 158 mA h g–1 at 10C rate demonstrates its remarkable rate capability. Additionally, the Mg doping significantly elevates the exothermic peak temperature of NC-Mg to 211 °C, in sharp contrast to 177 °C for NC, highlighting the improved thermal stability of NC-Mg. Collectively, the superior performance of NC-Mg demonstrates a feasible alternative strategy for developing safer, high-energy-density LIBs
