The Experts below are selected from a list of 24066 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 Polysulfide-Trapping Interface for Electrochemically Stable Sulfur Cathode Development
ACS Applied Materials & Interfaces, 2016Co-Authors: Sheng Heng Chung, Pauline Han, Arumugam ManthiramAbstract:Lithium–sulfur (Li–S) cells have a strong edge to become an inexpensive, high-capacity rechargeable battery system. However, currently, several prohibitive challenges occur within the sulfur core, especially the polysulfide-diffusion problem. To address these scientific issues, we present here a boron-doped multiwalled carbon nanotube coated separator (B-CNT-coated separator). The B-CNT-coated separator creates a polysulfide trap between the pure sulfur cathode and the polymeric separator as a “polysulfide-trapping interface,” stabilizing the active material and allowing the dissolved Polysulfides to activate the bulk sulfur cores. Therefore, the dissolved Polysulfides change from causing fast capacity fade to assisting with the activation of bulk sulfur clusters in pure sulfur cathodes. Moreover, the heteroatom-doped polysulfide-trapping interface is currently one of the missing pieces of carbon-coated separators, which might inspire further studies in its effect and battery chemistry. Li–S cells employi...
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room temperature sodium sulfur batteries with liquid phase sodium polysulfide catholytes and binder free multiwall carbon nanotube fabric electrodes
Journal of Physical Chemistry C, 2014Co-Authors: Arumugam ManthiramAbstract:Charge/discharge of a room-temperature sodium–sulfur (Na–S) battery involves redox processes of a series of long-chain soluble sodium Polysulfides (Na2Sn, 4 ≤ n ≤ 8). By taking advantage of this, a room-temperature Na–S battery is developed with dissolved sodium polysulfide catholyte and a free-standing, binder-free multiwall carbon nanotube (MWCNT) fabric electrode. Use of liquid-phase sodium polysulfide as a cathode not only provides a facile dispersion and homogeneous distribution of the sulfur active material into the conductive matrix but also supplies a unique approach to mechanistically understand the ambient-temperature Na–S battery system. With the intermediate products (Polysulfides) as the starting cathode, the electrochemical characteristics of the Na–S battery in the lower-voltage-plateau region can be readily studied without the impact from the transformation process of elemental sulfur into long-chain sodium Polysulfides. The nanostructured, free-standing MWCNT fabric electrode in this batt...
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a natural carbonized leaf as polysulfide diffusion inhibitor for high performance lithium sulfur battery cells
Chemsuschem, 2014Co-Authors: Sheng Heng Chung, Arumugam ManthiramAbstract:Attracted by the unique tissue and functions of leaves, a natural carbonized leaf (CL) is presented as a polysulfide diffusion inhibitor in lithium-sulfur (Li-S) batteries. The CL that is covered on the pure sulfur cathode effectively suppresses the polysulfide shuttling mechanism and enables the use of pure sulfur as the cathode. A low charge resistance and a high discharge capacity of 1320 mA h g(-1) arise from the improved cell conductivity due to the innately integral conductive carbon network of the CL. The unique microstructure of CL leads to a high discharge/charge efficiency of >98 %, low capacity fade of 0.18 % per cycle, and good long-term cyclability over 150 cycles. The structural gradient and the micro/mesoporous adsorption sites of CL effectively intercept/trap the migrating Polysulfides and facilitate their reutilization. The green CL polysulfide diffusion inhibitor thus offers a viable approach for developing high-performance lithium-sulfur batteries.
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highly reversible room temperature sulfur long chain sodium polysulfide batteries
Journal of Physical Chemistry Letters, 2014Co-Authors: Arumugam ManthiramAbstract:In a room-temperature sodium-sulfur (RT Na-S) battery, the complicated reduction reaction of the sulfur cathode generally involves two main steps: (i) transformation of elemental sulfur into long-chain soluble sodium Polysulfides (Na2Sn 4 ≤ n ≤ 8) and (ii) conversion of the long-chain sodium Polysulfides into solid-state short-chain polysulfide Na2S2 or disulfide Na2S. It is found that the slow kinetics of the second step limits the efficiency of discharge and induces irreversible capacity loss during cycling. Accordingly, we present here a RT Na-S cell operated with the sulfur/long-chain sodium polysulfide redox couple to avoid the capacity fade. An advanced cathode structure has been developed by inserting a carbon nanofoam interlayer between the sulfur cathode and the separator to localize the soluble polysulfide species and prevent its migration to the anode. The highly reversible sulfur/long-chain sodium polysulfide cell presented here can provide a stable output energy density of 450 Wh kg(-1) at an extremely low energy cost of ∼$10 kWh(-1) (based on the active material of anode and cathode).
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carbonized eggshell membrane as a natural polysulfide reservoir for highly reversible li s batteries
Advanced Materials, 2014Co-Authors: Sheng Heng Chung, Arumugam ManthiramAbstract:Carbonized sucrose-coated eggshell membranes (CSEMs) consisting of natural micropores function well as a polysulfide reservoir in Li/dissolved polysulfide cells. The bottom CSEM current collector encapsulates the active material, while the upper CSEM inhibitor intercepts the migrating Polysulfides. This design with CSEM allows the dissolved Polysulfides to be localized and the electrochemical reactions within the cathode region to be stabilized, resulting in high discharge capacity, long-term cycle stability, and high sulfur loading.
Jun Liu - One of the best experts on this subject based on the ideXlab platform.
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on the way toward understanding solution chemistry of lithium Polysulfides for high energy li s redox flow batteries
Advanced Energy Materials, 2015Co-Authors: Huilin Pan, Jie Xiao, Xiaoliang Wei, Wesley A Henderson, Yuyan Shao, Junzheng Chen, Priyanka Bhattacharya, Jun LiuAbstract:Lithium–sulfur (Li–S) redox flow battery (RFB) is a promising candidate for high energy large-scale energy storage application due to good solubility of long-chain polysulfide species and low cost of sulfur. Here, the fundamental understanding and control of lithium polysulfide chemistry are studied to enable the development of liquid phase Li–S redox flow prototype cells. These differ significantly from conventional static Li–S batteries targeting for vehicle electrification. A high solubility of the different lithium Polysulfides generated at different depths of discharge and states of charge is required for a flow battery in order to take full advantage of the multiple electron transitions. A new dimethyl sulfoxide based electrolyte is proposed for Li–S RFBs, which not only enables the high solubility of lithium polysulfide species, especially for the short-chain species, but also results in excellent cycling with a high Coulombic efficiency. The challenges and opportunities for the Li–S redox flow concept have also been discussed in depth.
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lewis acid base interactions between Polysulfides and metal organic framework in lithium sulfur batteries
Nano Letters, 2014Co-Authors: Jianming Zheng, Jian Tian, Chongmin Wang, Fei Gao, Mark H Engelhard, Ji Guang Zhang, Jun Liu, Jie XiaoAbstract:Lithium-sulfur (Li-S) battery is one of the most promising energy storage systems because of its high specific capacity of 1675 mAh g(-1) based on sulfur. However, the rapid capacity degradation, mainly caused by polysulfide dissolution, remains a significant challenge prior to practical applications. This work demonstrates that a novel Ni-based metal organic framework (Ni-MOF), Ni6(BTB)4(BP)3 (BTB = benzene-1,3,5-tribenzoate and BP = 4,4'-bipyridyl), can remarkably immobilize Polysulfides within the cathode structure through physical and chemical interactions at molecular level. The capacity retention achieves up to 89% after 100 cycles at 0.1 C. The excellent performance is attributed to the synergistic effects of the interwoven mesopores (∼2.8 nm) and micropores (∼1.4 nm) of Ni-MOF, which first provide an ideal matrix to confine Polysulfides, and the strong interactions between Lewis acidic Ni(II) center and the polysulfide base, which significantly slow down the migration of soluble Polysulfides out of the pores, leading to the excellent cycling performance of Ni-MOF/S composite.
M. Kavčič - One of the best experts on this subject based on the ideXlab platform.
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Fingerprinting mean composition of lithium polysulfide standard solutions by applying high energy resolution fluorescence detected X-ray Absorption Spectroscopy
Journal of Physical Chemistry Letters, 2020Co-Authors: A. Robba, C. Barchasz, K. Bučar, M. Petric, M. Žitnik, K. Kvashnina, G. Vaughan, R. Bouchet, F. Alloin, M. KavčičAbstract:In a lithium/sulfur (Li/S) battery, the reduction of sulfur along discharge involves a particular mechanism, where the active material successively dissolves into the electrolyte to form lithium Polysulfides intermediate species (Li2Sx), with x being a function of state of charge. In this work, sulfur K-edge Resonant Inelastic X-ray Scattering measurements were applied for the characterization of different Li2Sx polysulfide standard solutions. High Energy Resolution Fluorescence Detected X-ray Absorption Spectroscopy allowed to separate clearly the pre-edge absorption peak corresponding to terminal sulfur atoms from the main absorption peak due to internal atoms, and to evaluate quantitatively the evolution of the peak area ratio as a function of the polysulfide chain length. Results of this experimental work demonstrate that the normalized area of the pre-edge is a reliable fingerprint of Li2Sx mean chain length in agreement with recent theoretical predictions. As a perspective, this work confirms that operando HERFD XAS can be used to differentiate Polysulfides mean composition, which is key issue in the characterization of Li/S cells.
Leela Mohana Reddy Arava - One of the best experts on this subject based on the ideXlab platform.
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two dimensional material reinforced separator for li sulfur battery
Journal of Physical Chemistry C, 2018Co-Authors: Ganguli Babu, Abdulrazzag Sawas, Naresh Kumar Thangavel, Leela Mohana Reddy AravaAbstract:Li–S batteries are heavily researched as they are capable of meeting the demands of electrification of transport systems, provided their inherent polysulfide shuttling can be prevented to enhance the cycle life. Although several approaches have been made to mitigate the shuttling effect, success is limited due to the poor adsorption capability of Polysulfides on the cathode surface. Herein, we propose an efficient approach of using two-dimensional materials with permanent dipoles in the separator to inhibit mass transport of Polysulfides from cathode and subsequent parasitic reactions on the metallic lithium anode. Two-compartment H-cell experiments coupled with spectroscopic studies, such as ultraviolet–visible absorption, nuclear magnetic resonance spectroscopy, and Fourier transform infrared spectroscopy, are used to demonstrate the interactions between the two-dimensional materials-modified separator and polysulfide species. Furthermore, electrochemical properties reveal the excellent specific capacit...
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transition metal dichalcogenide atomic layers for lithium Polysulfides electrocatalysis
Journal of the American Chemical Society, 2017Co-Authors: Ganguli Babu, Hesham Al Salem, Nirul Masurkar, Leela Mohana Reddy AravaAbstract:Lithium–sulfur (Li–S) chemistry is projected to be one of the most promising for next-generation battery technology, and controlling the inherent “polysulfide shuttle” process has become a key research topic in the field. Regulating intermediary polysulfide dissolution by understanding the metamorphosis is essential for realizing stable and high-energy-density Li–S batteries. As of yet, a clear consensus on the basic surface/interfacial properties of the sulfur electrode has not been achieved, although the catalytic phenomenon has been shown to result in enhanced cell stability. Herein, we present evidence that the polysulfide shuttle in a Li–S battery can be stabilized by using electrocatalytic transition metal dichalcogenides (TMDs). Physicochemical transformations at the electrode/electrolyte interface of atomically thin monolayer/few-layer TMDs were elucidated using a combination of spectroscopic and microscopic analysis techniques. Preferential adsorption of higher order liquid Polysulfides and subse...
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electrocatalytic polysulfide traps for controlling redox shuttle process of li s batteries
Journal of the American Chemical Society, 2015Co-Authors: Hesham Al Salem, Ganguli Babu, Chitturi Venkateswara Rao, Leela Mohana Reddy AravaAbstract:Stabilizing the polysulfide shuttle while ensuring high sulfur loading holds the key to realizing high theoretical energy of lithium–sulfur (Li–S) batteries. Herein, we present an electrocatalysis approach to demonstrate preferential adsorption of a soluble polysulfide species, formed during discharge process, toward the catalyst anchored sites of graphene and their efficient transformation to long-chain Polysulfides in the subsequent redox process. Uniform dispersion of catalyst nanoparticles on graphene layers has shown a 40% enhancement in the specific capacity over pristine graphene and stability over 100 cycles with a Coulombic efficiency of 99.3% at a current rate of 0.2 C. Interaction between electrocatalyst and Polysulfides has been evaluated by conducting X-ray photoelectron spectroscopy and electron microscopy studies at various electrochemical conditions.
Jim Yang Lee - One of the best experts on this subject based on the ideXlab platform.
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a cathode integrated sulfur deficient co9s8 catalytic interlayer for the reutilization of lost Polysulfides in lithium sulfur batteries
ACS Nano, 2019Co-Authors: Haibin Lin, Tianran Zhang, Qiaofeng Yao, Guangyuan Wesley Zheng, Shengliang Zhang, Sheng Cao, Jim Yang LeeAbstract:Lithium–sulfur batteries, with their high theoretical energy density and the low material cost of sulfur, are highly promising as a post-lithium ion battery contender. Their current performance is however compromised by sulfur loss and polysulfide shuttle to result in low energy efficiency and poor cycle stability. Herein, a catalytic material (Co9S8–x/CNT, nanoparticles with a metallic Co9S8 core and a sulfur-deficient shell on a CNT support) was applied as an interlayer on the sulfur cathode to retain migratory Polysulfides and promote their reutilization. The Co9S8–x/CNT catalyst is highly effective for the conversion of Polysulfides to insoluble end products (S or Li2S/Li2S2), and its deployment as a cathode-integrated interlayer was able to retain the Polysulfides in the cathode for reuse. The accumulation of Polysulfides in the electrolyte and the polysulfide shuttle were significantly reduced as a result. Consequently, a host-free sulfur cathode with the Co9S8–x/CNT interlayer had a low capacity fa...
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electrocatalysis of polysulfide conversion by sulfur deficient mos2 nanoflakes for lithium sulfur batteries
Energy and Environmental Science, 2017Co-Authors: Haibin Lin, Liuqing Yang, Xi Jiang, Tianran Zhang, Qiaofeng Yao, Guangyuan Wesley Zheng, Jim Yang LeeAbstract:Lithium–sulfur batteries are promising next-generation energy storage devices due to their high energy density and low material cost. Efficient conversion of lithium Polysulfides to lithium sulfide (during discharge) and to sulfur (during recharge) is a performance-determining factor for lithium–sulfur batteries. Here we show that MoS2−x/reduced graphene oxide (MoS2−x/rGO) can be used to catalyze the polysulfide reactions to improve the battery performance. It was confirmed, through microstructural characterization of the materials, that sulfur deficiencies on the surface participated in the polysulfide reactions and significantly enhanced the polysulfide conversion kinetics. The fast conversion of soluble Polysulfides decreased their accumulation in the sulfur cathode and their loss from the cathode by diffusion. Hence in the presence of a small amount of MoS2−x/rGO (4 wt% of the cathode mass), high rate (8C) performance of the sulfur cathode was improved from a capacity of 161.1 mA h g−1 to 826.5 mA h g−1. In addition, MoS2−x/rGO also enhanced the cycle stability of the sulfur cathode from a capacity fade rate of 0.373% per cycle (over 150 cycles) to 0.083% per cycle (over 600 cycles) at a typical 0.5C rate. These results provide direct experimental evidence for the catalytic role of MoS2−x/rGO in promoting the polysulfide conversion kinetics in the sulfur cathode.
