The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform

Yi Cui - One of the best experts on this subject based on the ideXlab platform.

  • improved lithium sulfur batteries with a Conductive Coating on the separator to prevent the accumulation of inactive s related species at the cathode separator interface
    Energy and Environmental Science, 2014
    Co-Authors: Hongbin Yao, Kai Yan, Weiyang Li, Guangyuan Zheng, Desheng Kong, Zhi Wei Seh, Vijay K Narasimhan, Zheng Liang, Yi Cui
    Abstract:

    Lithium–sulfur (Li–S) batteries are highly attractive for future generations of portable electronics and electric vehicles due to their high energy density and potentially low cost. In the past decades, various novel electrodes and electrolytes have been tested to improve Li–S battery performance. However, these designs on electrodes and electrolytes have not fully addressed the problem of low cycling stability of Li–S batteries. Here, we show the role of the separator in the capacity decay of the Li–S battery, namely that it can accommodate a large amount of polysulfides inside which then precipitates as a thick layer of inactive S-related species. Using a thin Conductive Coating on the separator to prevent the formation of the inactive S-related species layer, we show that the specific capacity and cycling stability of the Li–S battery are both improved significantly compared to the battery with a pristine separator. Combining this separator design with a monodisperse sulfur nanoparticle cathode, we show Li–S batteries with a life of over 500 cycles with an initial specific capacity of 1350 mA h g−1 at C/2 and a cycle decay as low as 0.09% per cycle.

Alvo Aabloo - One of the best experts on this subject based on the ideXlab platform.

  • Conducting polymer actuators formed on MWCNT and PEDOT-PSS Conductive Coatings
    Synthetic Metals, 2013
    Co-Authors: Rudolf Kiefer, Rauno Temmer, Tarmo Tamm, Paul A. Kilmartin, Jadranka Travas-sejdic, Alvo Aabloo
    Abstract:

    Abstract To obtain bilayer or trilayer conducting polymer actuators, a Conductive Coating, such as gold, on a non-Conductive flexible polymer layer is required to assure high conductivity for the electrochemical deposition of the conducting polymer. In this study, we focus on the replacement of such metal layer by Conductive Coatings based on multi-wall carbon nanotubes (MWCNT), poly(3,4-ethylenedioxythiophene) doped with poly(4-vinylbenzenesulfonate) (polystyrene sulfonate) (PEDOT-PSS), and mixtures of the two (PEDOT-PSS/MWCNT). The actuator performance of polypyrrole doped with dodecylbenzenesulfonate (PPy-DBS) on these Conductive Coatings, deposited on poly(ethylene terephthalate) (PET) films, were investigated using electrochemical experiments. Different PEDOT-PSS/MWCNT ratios in the Conductive Coating layer deposited with PPy-DBS affected the actuator displacement. The actuator constructed using PPy-DBS on PEDOT-PSS/MWCNT showed cycling stability up to 14,000 cycles at 1 Hz.

  • Conducting polymer actuators formed on MWCNT and PEDOT-PSS Conductive Coatings
    Synthetic Metals, 2013
    Co-Authors: Rudolf Kiefer, Rauno Temmer, Tarmo Tamm, Paul A. Kilmartin, Jadranka Travas-sejdic, Alvo Aabloo
    Abstract:

    To obtain bilayer or trilayer conducting polymer actuators, a Conductive Coating, such as gold, on a non-Conductive flexible polymer layer is required to assure high conductivity for the electrochemical deposition of the conducting polymer. In this study, we focus on the replacement of such metal layer by Conductive Coatings based on multi-wall carbon nanotubes (MWCNT), poly(3,4-ethylenedioxythiophene) doped with poly(4-vinylbenzenesulfonate) (polystyrene sulfonate) (PEDOT-PSS), and mixtures of the two (PEDOT-PSS/MWCNT). The actuator performance of polypyrrole doped with dodecylbenzenesulfonate (PPy-DBS) on these Conductive Coatings, deposited on poly(ethylene terephthalate) (PET) films, were investigated using electrochemical experiments. Different PEDOT-PSS/MWCNT ratios in the Conductive Coating layer deposited with PPy-DBS affected the actuator displacement. The actuator constructed using PPy-DBS on PEDOT-PSS/MWCNT showed cycling stability up to 14,000 cycles at 1 Hz. © 2013 Elsevier B.V. All rights reserved.

Ying Shirley Meng - One of the best experts on this subject based on the ideXlab platform.

  • lithium lanthanum titanium oxides a fast ionic Conductive Coating for lithium ion battery cathodes
    Chemistry of Materials, 2012
    Co-Authors: Danna Qian, Bo Xu, Toru Hatsukade, Kyler J Carroll, Ying Shirley Meng
    Abstract:

    This work introduces Li–La–Ti–O (LLTO), which is a fast lithium-ion conductor, as an effective Coating material for cathode materials used in rechargeable lithium-ion batteries. This fast Li-ion conductor is characterized by first-principles calculations showing low activation barrier for lithium diffusion at various different lithium concentrations. The morphology and the microstructure of the pristine electrode and coated electrode materials are characterized systematically, and we show clear evidence of the presence of the Coating after electrochemical cycling. The coated electrodes show significantly improved rate capabilities and cycling performance, compared to the pristine electrodes. The possible reasons for such enhancements are explored experimentally using potentiostatic intermittent titration technique (PITT), electrochemical impedance spectroscopy (EIS). Because of the high lithium conductivity in the LLTO Coating material, the chemical Li+ diffusion coefficient is one magnitude of order high...

Rudolf Kiefer - One of the best experts on this subject based on the ideXlab platform.

  • Conducting polymer actuators formed on MWCNT and PEDOT-PSS Conductive Coatings
    Synthetic Metals, 2013
    Co-Authors: Rudolf Kiefer, Rauno Temmer, Tarmo Tamm, Paul A. Kilmartin, Jadranka Travas-sejdic, Alvo Aabloo
    Abstract:

    Abstract To obtain bilayer or trilayer conducting polymer actuators, a Conductive Coating, such as gold, on a non-Conductive flexible polymer layer is required to assure high conductivity for the electrochemical deposition of the conducting polymer. In this study, we focus on the replacement of such metal layer by Conductive Coatings based on multi-wall carbon nanotubes (MWCNT), poly(3,4-ethylenedioxythiophene) doped with poly(4-vinylbenzenesulfonate) (polystyrene sulfonate) (PEDOT-PSS), and mixtures of the two (PEDOT-PSS/MWCNT). The actuator performance of polypyrrole doped with dodecylbenzenesulfonate (PPy-DBS) on these Conductive Coatings, deposited on poly(ethylene terephthalate) (PET) films, were investigated using electrochemical experiments. Different PEDOT-PSS/MWCNT ratios in the Conductive Coating layer deposited with PPy-DBS affected the actuator displacement. The actuator constructed using PPy-DBS on PEDOT-PSS/MWCNT showed cycling stability up to 14,000 cycles at 1 Hz.

  • Conducting polymer actuators formed on MWCNT and PEDOT-PSS Conductive Coatings
    Synthetic Metals, 2013
    Co-Authors: Rudolf Kiefer, Rauno Temmer, Tarmo Tamm, Paul A. Kilmartin, Jadranka Travas-sejdic, Alvo Aabloo
    Abstract:

    To obtain bilayer or trilayer conducting polymer actuators, a Conductive Coating, such as gold, on a non-Conductive flexible polymer layer is required to assure high conductivity for the electrochemical deposition of the conducting polymer. In this study, we focus on the replacement of such metal layer by Conductive Coatings based on multi-wall carbon nanotubes (MWCNT), poly(3,4-ethylenedioxythiophene) doped with poly(4-vinylbenzenesulfonate) (polystyrene sulfonate) (PEDOT-PSS), and mixtures of the two (PEDOT-PSS/MWCNT). The actuator performance of polypyrrole doped with dodecylbenzenesulfonate (PPy-DBS) on these Conductive Coatings, deposited on poly(ethylene terephthalate) (PET) films, were investigated using electrochemical experiments. Different PEDOT-PSS/MWCNT ratios in the Conductive Coating layer deposited with PPy-DBS affected the actuator displacement. The actuator constructed using PPy-DBS on PEDOT-PSS/MWCNT showed cycling stability up to 14,000 cycles at 1 Hz. © 2013 Elsevier B.V. All rights reserved.

John B Goodenough - One of the best experts on this subject based on the ideXlab platform.

  • development and challenges of lifepo4 cathode material for lithium ion batteries
    Energy and Environmental Science, 2011
    Co-Authors: Lixia Yuan, Zhaohui Wang, Wu Xing Zhang, Xian Luo Hu, Ji Tao Chen, Yunhui Huang, John B Goodenough
    Abstract:

    The olivine LiFePO4 now stands as a competitive candidate of cathode material for the next generation of a green and sustainable lithium-ion battery system due to its long life span, abundant resources, low toxicity, and high thermal stability. In this review, we focus on LiFePO4 and discuss its structure, synthesis, electrochemical behavior, mechanism, and the problems encountered in its application. The major goal is to highlight some recent development of LiFePO4 with high rate capability, high energy density, and excellent cyclability resulting from Conductive Coating, nanocrystallization, or preparation.