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Guoxiu Wang - One of the best experts on this subject based on the ideXlab platform.

  • enabling immobilization and conversion of polysulfides through a nitrogen doped carbon nanotubes ultrathin mos2 nanosheet core shell architecture for lithium sulfur Batteries
    Journal of Materials Chemistry, 2019
    Co-Authors: Guoxiu Wang, Wu Yang, Wang Yang, Xiaochun Gao, Liubing Dong, Guangjie Shao
    Abstract:

    Lithium–sulfur Batteries are widely considered as promising next generation energy storage devices due to their high energy density and low cost. However, the shuttle effect and sluggish kinetics of polysulfide conversion are still key challenges for practical application. Herein, we designed hierarchical nitrogen-doped carbon nanotubes/ultrathin molybdenum disulfide nanosheets in a core–shell architecture (denoted as NC@MoS2) to alleviate the shuttle effect and propel redox reaction kinetics, thereby improving the electrochemical performance of lithium–sulfur Batteries. Both experimental investigations and theoretical studies reveal that MoS2 nanosheets can chemically immobilize lithium polysulfides and catalyze the conversion of polysulfides. Moreover, this unique core–shell architecture could facilitate rapid electrical transport and favorable electrolyte infiltration. We have demonstrated that the obtained S–NC@MoS2 cathodes exhibit excellent rate capability (516 mA h g−1 at 5C) and superior cycle stability (only 0.049% capacity decay per cycle up to 1000 cycles at 2C). Remarkably, the composite cathode with a high sulfur loading of 3.6 mg cm−2 still maintains high rate capability and stable cycling performance over 300 cycles. This work offers a new strategy to develop high-performance lithium–sulfur Batteries through the exploration of two-dimensional mediator catalysts.

  • self standing sulfur cathodes enabled by 3d hierarchically porous titanium monoxide graphene composite film for high performance lithium sulfur Batteries
    Nano Energy, 2018
    Co-Authors: Yi Chen, Sinho Choi, Xiaochun Gao, Guoxiu Wang
    Abstract:

    Abstract Although Lithium-Sulfur Batteries show great promise for next-generation energy storage due to their high energy density, the practical implementation of Lithium-Sulfur Batteries has been largely impeded by the shuttle effect of lithium polysulfides and low areal capacity ( 1350  mAh g−1 at 0.1 C, a Coulombic efficiency approaching 100%, and a high-rate capacity of 832 mAh g−1 at 2 C. Moreover, when the areal sulfur loading was increased to 5.2 mg cm−2, the titanium monoxide-graphene/sulfur electrode delivered a high areal capacity of 3.2 mAh cm−2 after 300 cycles at 0.2 C, demonstrating excellent cycling performance compared with other recently reported sulfur cathodes with high areal sulfur loadings.

  • 3d metal carbide mesoporous carbon hybrid architecture as a new polysulfide reservoir for lithium sulfur Batteries
    Advanced Functional Materials, 2016
    Co-Authors: Weizhai Bao, W X Zhang, Xin Guo, Guoxiu Wang
    Abstract:

    3D metal carbide@mesoporous carbon hybrid architecture (Ti3C2Tx@Meso-C, TX ≈ FxOy) is synthesised and applied as cathode material hosts for Lithium-Sulfur Batteries. Exfoliated-metal carbide (Ti3C2Tx) nanosheets have high electronic conductivity and contain rich functional groups for effective trapping of polysulfides. Mesoporous carbon with a robust porous structure provides sufficient spaces for loading sulfur and effectively cushion the volumetric expansion of sulfur cathodes. Theoretical calculations have confirmed that metal carbide can absorb sulfur and polysulfides, therefore extending the cycling performance. The Ti3C2Tx@Meso-C/S cathodes have achieved a high capacity of 1225.8 mAh g−1 and more than 300 cycles at the C/2 current rate. The Ti3C2Tx@Meso-C hybrid architecture is a promising cathode host material for Lithium-Sulfur Batteries.

  • immobilizing polysulfides with mxene functionalized separators for stable lithium sulfur Batteries
    ACS Applied Materials & Interfaces, 2016
    Co-Authors: Jianjun Song, Weizhai Bao, Xin Guo, Guangjie Shao, Xiuqiang Xie, Guoxiu Wang
    Abstract:

    Lithium–sulfur Batteries have attracted increasing attention as one of the most promising candidates for next-generation energy storage systems. However, the poor cycling performance and the low utilization of sulfur greatly hinder its practical applications. Here we report the improved performance of lithium–sulfur Batteries by coating Ti3C2Tx MXene nanosheets (where T stands for the surface termination, such as -O, -OH, and/or -F) on commercial “Celgard” membrane. In favor of the ultrathin two-dimensional structure, the Ti3C2Tx MXene can form a uniform coating layer with a minimum mass loading of 0.1 mg cm–2 and a thickness of only 522 nm. Owing to the improved electric conductivity and the effective trapping of polysulfides, the lithium–sulfur Batteries with MXene-functionalized separators exhibit superior performance including high specific capacities and cycling stability.

  • Immobilizing Polysulfides with MXene-Functionalized Separators for Stable Lithium–Sulfur Batteries
    2016
    Co-Authors: Jianjun Song, Weizhai Bao, Xin Guo, Guangjie Shao, Xiuqiang Xie, Guoxiu Wang
    Abstract:

    Lithium–sulfur Batteries have attracted increasing attention as one of the most promising candidates for next-generation energy storage systems. However, the poor cycling performance and the low utilization of sulfur greatly hinder its practical applications. Here we report the improved performance of lithium–sulfur Batteries by coating Ti3C2Tx MXene nanosheets (where T stands for the surface termination, such as -O, -OH, and/or -F) on commercial “Celgard” membrane. In favor of the ultrathin two-dimensional structure, the Ti3C2Tx MXene can form a uniform coating layer with a minimum mass loading of 0.1 mg cm–2 and a thickness of only 522 nm. Owing to the improved electric conductivity and the effective trapping of polysulfides, the lithium–sulfur Batteries with MXene-functionalized separators exhibit superior performance including high specific capacities and cycling stability

Qiang Zhang - One of the best experts on this subject based on the ideXlab platform.

  • cnts s composite as cathode for all solid state lithium sulfur Batteries with ultralong cycle life
    Journal of Energy Chemistry, 2020
    Co-Authors: Qiang Zhang, Ning Huang, Zhen Huang, Liangting Cai, Xiayin Yao
    Abstract:

    Abstract The main challenges in development of traditional liquid Lithium-Sulfur Batteries are the shuttle effect at the cathode caused by the polysulfide and the safety concern at the Li metal anode arose from the dendrite formation. All-solid-state Lithium-Sulfur Batteries have been proposed to solve the shuttle effect and prevent short circuits. However, solid-solid contacts between the electrodes and the electrolyte increase the interface resistance and stress/strain, which could result in the limited electrochemical performances. In this work, the cathode of all-solid-state Lithium-Sulfur Batteries is prepared by depositing sulfur on the surface of the carbon nanotubes (CNTs@S) and further mixing with Li10GeP2S12 electrolyte and acetylene black agents. At 60  °C, CNTs@S electrode exhibits superior electrochemical performance, delivering the reversible discharge capacities of 1193.3, 959.5, 813.1, 569.6 and 395.5 mAh g−1 at the rate of 0.1, 0.5, 1, 2 and 5 C, respectively. Moreover, the CNTs@S is able to demonstrate superior high-rate capability of 660.3 mAh g−1 and cycling stability of 400 cycles at a high rate of 1.0 C. Such uniform distribution of the CNTs, S and Li10GeP2S12 electrolyte increase the electronic and ionic conductivity between the cathode and the electrolyte hence improves the rate performance and capacity retention.

  • rational design of multi channel continuous electronic ionic conductive networks for room temperature vanadium tetrasulfide based all solid state lithium sulfur Batteries
    Nano Energy, 2019
    Co-Authors: Qiang Zhang, Hongli Wan, Gaozhan Liu, Zhaoguang Ding, Jean Pierre Mwizerwa, Xiayin Yao
    Abstract:

    Abstract All-solid-state Lithium-Sulfur Batteries can completely overcome safety issues and fast capacity fading by substitution of organic liquid electrolytes and eliminating polysulfide shuttle. However, the insulating nature of sulfur and large volume change still inhibit all-solid-state Lithium-Sulfur Batteries from achieving favorable electrochemical performances. In this work, linear-chain compound vanadium tetrasulfide (VS4) anchored reduced graphene oxide (rGO-VS4) nanocomposites are successfully synthesized via a simple one-pot hydrothermal method. Furthermore, 10%rGO-VS4@Li7P3S11 nanocomposites with multi-channel continuous electronic/ionic conductive network are prepared by a facile liquid-phase deposition reaction and further employed as an alternative material for sulfur cathode in all-solid-state lithium Batteries. Typically, Li/75%Li2S-24%P2S5-1%P2O5/Li10GeP2S12/10%rGO-VS4@Li7P3S11 all-solid-state Lithium-Sulfur Batteries deliver high reversible capacity of 611 mAh g−1 at 0.1 A g−1 after 100 cycles, corresponding to 853 mAh g−1 based on the mass of sulfur. Even after being cycled at 0.5 A g−1 between 1.5 and 3.0 V for 500 cycles, it still shows the discharge specific capacity of 333 mAh g−1 based on sulfur content with excellent cycling stability. The excellent rate capability and cycle performances can be ascribed to the multi-channel continuous electronic/ionic conductive networks and the improved structural stability. In addition, the electrochemical reaction kinetics and capacity contributions as well as reaction mechanisms of 10%rGO-VS4@Li7P3S11 in all-solid-state lithium Batteries were revealed by ex-situ characterization techniques.

  • two dimensional vermiculite separator for lithium sulfur Batteries
    Chinese Chemical Letters, 2017
    Co-Authors: Rui Xu, Yunfei Wang, Jiaqi Huang, Qiang Zhang
    Abstract:

    Abstract Lithium-Sulfur Batteries have been considered as one of the most promising battery system for their high theoretical energy density. However, the Lithium-Sulfur Batteries suffer from the dissolution and diffusion of polysulfides, which induce parasitic reactions with lithium metal anodes. The safety of Lithium-Sulfur Batteries is also concerned with the risk of dendrite growth on lithium metal anodes. To simultaneously address the challenges in the shuttle effect and safety problems, we demonstrate herein a two-dimensional vermiculite separator. With the assembly of the 2D exfoliated vermiculite sheets, the vermiculite separator can suppress the diffusion of polysulfides across the separator through electrostatic interaction and steric hindrance. Meanwhile, the inorganic sheets with high strength and Young’s modulus prevent the penetration of lithium metal dendrite and potentially improve the safety of the system. This work elucidates a promising strategy for safe and stable lithium sulfur Batteries, and can also be extended to other electrochemical systems based on metal anodes.

  • permselective graphene oxide membrane for highly stable and anti self discharge lithium sulfur Batteries
    ACS Nano, 2015
    Co-Authors: Jiaqi Huang, Hong-jie Peng, Qiang Zhang, Tingzhou Zhuang, Chengmeng Chen, Fei Wei
    Abstract:

    Lithium–sulfur Batteries hold great promise for serving as next generation high energy density Batteries. However, the shuttle of polysulfide induces rapid capacity degradation and poor cycling stability of lithium–sulfur cells. Herein, we proposed a unique lithium–sulfur battery configuration with an ultrathin graphene oxide (GO) membrane for high stability. The oxygen electronegative atoms modified GO into a polar plane, and the carboxyl groups acted as ion-hopping sites of positively charged species (Li+) and rejected the transportation of negatively charged species (Sn2–) due to the electrostatic interactions. Such electrostatic repulsion and physical inhibition largely decreased the transference of polysulfides across the GO membrane in the lithium–sulfur system. Consequently, the GO membrane with highly tunable functionalization properties, high mechanical strength, low electric conductivity, and facile fabrication procedure is an effective permselective separator system in lithium–sulfur Batteries....

  • Template growth of porous graphene microspheres on layered double oxide catalysts and their applications in Lithium-Sulfur Batteries
    Carbon, 2015
    Co-Authors: Jia Le Shi, Hong-jie Peng, Lin Zhu, Wancheng Zhu, Qiang Zhang
    Abstract:

    The wise integration of individual two-dimensional graphene nanosheets into three-dimensional (3D) macroscopic architectures is essential for full exploration of their potential applications in electrochemical energy storage. Graphene microspheres (GMSs) with hierarchical porous architectures and high 3D electrical conductivities are highly expected to be the host carbon to accommodate sulfur cathode for Lithium-Sulfur Batteries. Herein we reported the direct synthesis of GMSs assembled by 3D interconnected graphene with hierarchical pores by template chemical vapor deposition (CVD) on layered double oxide (LDO) microspheres. The LDO templates were derived from conformally calcined layered double hydroxide microspheres produced by spray drying. After methane-CVD, graphene was catalytically grown on LDO templates. Subsequent routine chemical etching of the LDO templates enabled as-obtained GMSs with a large diameter of ca. 11 μm and a high surface area of 1275 m2 g-1. The GMS was employed as carbon scaffold to accommodate sulfur for rechargeable Lithium-Sulfur Batteries. An initial areal discharge capacity of 2.67 mAh cm-2 was obtained at a current density of 0.83 mA cm-2 on flexible GMS paper electrode with an areal sulfur loading of 2.5 mg cm-2.

Guangjie Shao - One of the best experts on this subject based on the ideXlab platform.

  • enabling immobilization and conversion of polysulfides through a nitrogen doped carbon nanotubes ultrathin mos2 nanosheet core shell architecture for lithium sulfur Batteries
    Journal of Materials Chemistry, 2019
    Co-Authors: Guoxiu Wang, Wu Yang, Wang Yang, Xiaochun Gao, Liubing Dong, Guangjie Shao
    Abstract:

    Lithium–sulfur Batteries are widely considered as promising next generation energy storage devices due to their high energy density and low cost. However, the shuttle effect and sluggish kinetics of polysulfide conversion are still key challenges for practical application. Herein, we designed hierarchical nitrogen-doped carbon nanotubes/ultrathin molybdenum disulfide nanosheets in a core–shell architecture (denoted as NC@MoS2) to alleviate the shuttle effect and propel redox reaction kinetics, thereby improving the electrochemical performance of lithium–sulfur Batteries. Both experimental investigations and theoretical studies reveal that MoS2 nanosheets can chemically immobilize lithium polysulfides and catalyze the conversion of polysulfides. Moreover, this unique core–shell architecture could facilitate rapid electrical transport and favorable electrolyte infiltration. We have demonstrated that the obtained S–NC@MoS2 cathodes exhibit excellent rate capability (516 mA h g−1 at 5C) and superior cycle stability (only 0.049% capacity decay per cycle up to 1000 cycles at 2C). Remarkably, the composite cathode with a high sulfur loading of 3.6 mg cm−2 still maintains high rate capability and stable cycling performance over 300 cycles. This work offers a new strategy to develop high-performance lithium–sulfur Batteries through the exploration of two-dimensional mediator catalysts.

  • pyrrole as a promising electrolyte additive to trap polysulfides for lithium sulfur Batteries
    Journal of Power Sources, 2017
    Co-Authors: Wu Yang, Wang Yang, Ailing Song, Lijun Gao, Gang Sun, Guangjie Shao
    Abstract:

    Abstract Lithium–sulfur Batteries are a promising energy storage devices beyond conventional lithium ion Batteries. However, the “shuttle effect” of soluble polysulfides is a major barrier between electrodes, resulting in rapid capacity fading. To address above issue, pyrrole has been investigated as an electrolyte additive to trap polysulfides. When pyrrole is added into electrolyte, a surface protective layer of polypyrrole can be formed on the sulfur cathode, which not only acts as a conductive agent to provide an effective electron conduction path but also acts as an absorbing agent and barrier layer suppressing the diffusion of polysulfide intermediates. The results demonstrate that an appropriate amount of pyrrole added into the electrolyte leads to excellent cycling stability and rate capability. Apparently, pyrrole is an effective additive for the entrapment of polysulfides of Lithium-Sulfur Batteries.

  • immobilizing polysulfides with mxene functionalized separators for stable lithium sulfur Batteries
    ACS Applied Materials & Interfaces, 2016
    Co-Authors: Jianjun Song, Weizhai Bao, Xin Guo, Guangjie Shao, Xiuqiang Xie, Guoxiu Wang
    Abstract:

    Lithium–sulfur Batteries have attracted increasing attention as one of the most promising candidates for next-generation energy storage systems. However, the poor cycling performance and the low utilization of sulfur greatly hinder its practical applications. Here we report the improved performance of lithium–sulfur Batteries by coating Ti3C2Tx MXene nanosheets (where T stands for the surface termination, such as -O, -OH, and/or -F) on commercial “Celgard” membrane. In favor of the ultrathin two-dimensional structure, the Ti3C2Tx MXene can form a uniform coating layer with a minimum mass loading of 0.1 mg cm–2 and a thickness of only 522 nm. Owing to the improved electric conductivity and the effective trapping of polysulfides, the lithium–sulfur Batteries with MXene-functionalized separators exhibit superior performance including high specific capacities and cycling stability.

  • high capacity and cycle stability rechargeable lithium sulfur Batteries by sandwiched gel polymer electrolyte
    Electrochimica Acta, 2016
    Co-Authors: Wu Yang, Wang Yang, Jiani Feng, Guangjie Shao
    Abstract:

    Abstract A novel sandwiched gel polymer electrolyte (GPE) was prepared using a facile method as separator solely for rechargeable Lithium–Sulfur Batteries. As a result of the strong physical shielding and chemical absorption of GPE, the separator can not only suppress shuttle effect in ether-based electrolyte, but also improve utilization of sulfur significantly resulting in a high capacity. The PVDF layers could absorb ether-based electrolyte largely and then enhance Li + transfer; the PMMA layer can be utilized to trap the dissolved polysulfides. Lithium–Sulfur Batteries with the sandwiched GPE separator shows an encouraging electrochemical performance. A high initial discharge capacity of 1711.8 mAh g −1 is obtained, and the capacity retains at 1145.3 mAh g −1 after 50 cycles at 200 mA g −1 , which is higher than that of the cell with the commercial separator. These results indicate that the appropriate GPE separator is more suitable in Lithium−Sulfur Batteries applications.

  • Immobilizing Polysulfides with MXene-Functionalized Separators for Stable Lithium–Sulfur Batteries
    2016
    Co-Authors: Jianjun Song, Weizhai Bao, Xin Guo, Guangjie Shao, Xiuqiang Xie, Guoxiu Wang
    Abstract:

    Lithium–sulfur Batteries have attracted increasing attention as one of the most promising candidates for next-generation energy storage systems. However, the poor cycling performance and the low utilization of sulfur greatly hinder its practical applications. Here we report the improved performance of lithium–sulfur Batteries by coating Ti3C2Tx MXene nanosheets (where T stands for the surface termination, such as -O, -OH, and/or -F) on commercial “Celgard” membrane. In favor of the ultrathin two-dimensional structure, the Ti3C2Tx MXene can form a uniform coating layer with a minimum mass loading of 0.1 mg cm–2 and a thickness of only 522 nm. Owing to the improved electric conductivity and the effective trapping of polysulfides, the lithium–sulfur Batteries with MXene-functionalized separators exhibit superior performance including high specific capacities and cycling stability

Huiming Cheng - One of the best experts on this subject based on the ideXlab platform.

Fei Wei - One of the best experts on this subject based on the ideXlab platform.

  • permselective graphene oxide membrane for highly stable and anti self discharge lithium sulfur Batteries
    ACS Nano, 2015
    Co-Authors: Jiaqi Huang, Hong-jie Peng, Qiang Zhang, Tingzhou Zhuang, Chengmeng Chen, Fei Wei
    Abstract:

    Lithium–sulfur Batteries hold great promise for serving as next generation high energy density Batteries. However, the shuttle of polysulfide induces rapid capacity degradation and poor cycling stability of lithium–sulfur cells. Herein, we proposed a unique lithium–sulfur battery configuration with an ultrathin graphene oxide (GO) membrane for high stability. The oxygen electronegative atoms modified GO into a polar plane, and the carboxyl groups acted as ion-hopping sites of positively charged species (Li+) and rejected the transportation of negatively charged species (Sn2–) due to the electrostatic interactions. Such electrostatic repulsion and physical inhibition largely decreased the transference of polysulfides across the GO membrane in the lithium–sulfur system. Consequently, the GO membrane with highly tunable functionalization properties, high mechanical strength, low electric conductivity, and facile fabrication procedure is an effective permselective separator system in lithium–sulfur Batteries....

  • aligned carbon nanotube sulfur composite cathodes with high sulfur content for lithium sulfur Batteries
    Nano Energy, 2014
    Co-Authors: Xinbing Cheng, Hong-jie Peng, Qiang Zhang, Jiaqi Huang, Mengqiang Zhao, Fei Wei
    Abstract:

    Abstract The use of conductive carbon scaffolds is efficient and effective to obtain advanced composite cathodes for lithium–sulfur Batteries. However, the loading amount of mostly less than 70 wt% induces a limited energy density and the typical fabrication route involving high-temperature and elaborate process also limits the manufacturability of sulfur cathode, both of which hinder the practical application of lithium–sulfur Batteries. Herein, a scalable, room-temperature, and one-step method is employed for carbon nanotube (CNT)/sulfur composite cathode, in which aligned CNTs served as interconnected conductive scaffolds to accommodate sulfur. When the loading amount of sulfur increased from 50 to 90 wt%, the tap density of CNT/sulfur increased from 0.4 to 1.98 g cm −3 , and the mass/areal/volumetric capacities of the whole electrodes (CNT/sulfur composites and binders) was improved from 500.3 mAh g −1 /0.298 mAh cm −2 /200.1 mAh cm −3 to 563.7 mAh g −1 /0.893 mAh cm −2 /1116.0 mAh cm −3 , respectively. The rise of sulfur content in the composite cathode renders a dramatic increase of the energy density of lithium–sulfur cells. The ultra-high loading amount of sulfur is attributed to the open, ordered, straight pore structure of aligned CNT scaffolds for the uniform distribution of fine sulfur particles. The robust sp 2 carbon frameworks served as rapid pathways for electron transfer, and the large aspect ratio, good alignment, ordered packing of individual CNT in small bundles offer a low conductive percolation threshold. Consequently, the sulfur with a high loading content was efficiently utilized for a lithium–sulfur cell with a much improved energy density.

  • ionic shield for polysulfides towards highly stable lithium sulfur Batteries
    Energy and Environmental Science, 2014
    Co-Authors: Jiaqi Huang, Hong-jie Peng, Qiang Zhang, Xinyan Liu, Weizhong Qian, Fei Wei
    Abstract:

    Lithium–sulfur Batteries attract great attention due to their high energy density, while their real applications are still hindered by the rapid capacity degradation. Despite great efforts devoted to solving the polysulfide shuttle between the cathode and anode electrodes, it remains a serious challenge to build highly-stable lithium–sulfur Batteries. Herein we demonstrate a strategy of introducing an ion selective membrane to improve the stability and coulombic efficiency of lithium–sulfur Batteries. The sulfonate-ended perfluoroalkyl ether groups on the ionic separators are connected by pores or channels that are around several nanometers in size. These SO3− groups-coated channels allow ion hopping of positively charged species (Li+) but reject hopping of negative ions, such as polysulfide anions (Sn2−) in this specific case due to the coulombic interactions. Consequently, this cation permselective membrane acts as an electrostatic shield for polysulfide anions, and confines the polysulfides on the cathode side. An ultra-low decay rate of 0.08% per cycle is achieved within the initial 500 cycles for the membrane developed in this work, which is less than half that of the routine membranes. Such an ion selective membrane is versatile for various electrodes and working conditions, which is promising for the construction of high performance Batteries.