The Experts below are selected from a list of 4140 Experts worldwide ranked by ideXlab platform

Hongyu Huang - One of the best experts on this subject based on the ideXlab platform.

  • Lithium Hydroxide Reaction for Low Temperature Chemical Heat Storage: Hydration and Dehydration Reaction
    Energies, 2019
    Co-Authors: Tao Zeng, Noriyuki Kobayashi, Yu Bai, Lisheng Deng, Hongyu Huang
    Abstract:

    As a key parameter of a chemical heat storage material, the hydration and dehydration reaction characteristics of Lithium Hydroxide (LiOH) at pure vapor condition is unclear. In this study, we focused on the hydration reaction and dehydration process of LiOH at the pure vapor condition. The pressure–temperature diagram of LiOH equilibrium was measured. The hydration and dehydration of LiOH at various conditions have been experimentally investigated. The results show that the steam diffusion can be greatly enhanced at vacuum condition. A thin layer of LiOH is uniformly dispersed in the reactor, which can greatly increase the heat transfer between the LiOH material and reactor, leading to a higher hydration reaction rate of LiOH. Furthermore, the steam pressure, reaction temperature, and the particle size of LiOH can greatly influence the hydration reaction. A maximum hydration reaction rate of 80% is obtained under the conditions of 47 °C, steam pressure of 9 kPa, and particle size of 32–40 μm. LiOH exhibits a different reaction property at the condition of pure steam without air and below atmospheric pressure. A store and reaction condition of LiOH with isolation of air is recommended when apply LiOH as a heat storage material at low temperature.

  • The effect of 3D carbon nanoadditives on Lithium Hydroxide monohydrate based composite materials for highly efficient low temperature thermochemical heat storage
    RSC Advances, 2018
    Co-Authors: Hongyu Huang, Noriyuki Kobayashi, Yugo Osaka, Haoran Yuan
    Abstract:

    Lithium Hydroxide monohydrate based thermochemical heat storage materials were modified with in situ formed 3D-nickel-carbon nanotubes (Ni-CNTs). The nanoscale (5–15 nm) LiOH·H2O particles were well dispersed in the composite formed with Ni-CNTs. These composite materials exhibited improved heat storage capacity, thermal conductivity, and hydration rate owing to hydrogen bonding between H2O and hydrophilic groups on the surface of Ni-CNTs, as concluded from combined results of in situ DRIFT spectroscopy and heat storage performance test. The introduction of 3D-carbon nanomaterials leads to a considerable decrease in the activation energy for the thermochemical reaction process. This phenomenon is probably due to Ni-CNTs providing an efficient hydrophilic reaction interface and exhibiting a surface effect on the hydration reaction. Among the thermochemical materials, Ni-CNTs–LiOH·H2O-1 showed the lowest activation energy (23.3 kJ mol−1), the highest thermal conductivity (3.78 W m−1 K−1) and the highest heat storage density (3935 kJ kg−1), which is 5.9 times higher than that of pure Lithium Hydroxide after the same hydration time. The heat storage density and the thermal conductivity of Ni-CNTs–LiOH·H2O are much higher than 1D MWCNTs and 2D graphene oxide modified LiOH·H2O. The selection of 3D carbon nanoadditives that formed part of the chemical heat storage materials is a very efficient way to enhance comprehensive performance of heat storage activity components.

  • Facile synthesis of graphene oxide-modified Lithium Hydroxide for low-temperature chemical heat storage
    Chemical Physics Letters, 2016
    Co-Authors: Xixian Yang, Hongyu Huang, Zhihui Wang, Mitsuhiro Kubota, Noriyuki Kobayashi
    Abstract:

    Abstract LiOH·H 2 O nanoparticles supported on graphene oxide (GO) were facilely synthesized by a hydrothermal process. The mean diameter of nanoparticles on the integrated graphene sheet was about 5⿿10 nm showed by SEM and TEM results. XRD results suggested that the nanoparticles are in good agreement with the data of LiOH·H 2 O. The as-prepared sample showed a greatly enhanced thermal energy storage density and exhibit higher rate of heat release than pure Lithium Hydroxide, and thermal conductivity of composites increased due to the introduction of nano carbon. LiOH·H 2 O/GO nanocomposites are novel chemical heat storage materials for potential highly efficient energy system.

Noriyuki Kobayashi - One of the best experts on this subject based on the ideXlab platform.

  • Lithium Hydroxide Reaction for Low Temperature Chemical Heat Storage: Hydration and Dehydration Reaction
    Energies, 2019
    Co-Authors: Tao Zeng, Noriyuki Kobayashi, Yu Bai, Lisheng Deng, Hongyu Huang
    Abstract:

    As a key parameter of a chemical heat storage material, the hydration and dehydration reaction characteristics of Lithium Hydroxide (LiOH) at pure vapor condition is unclear. In this study, we focused on the hydration reaction and dehydration process of LiOH at the pure vapor condition. The pressure–temperature diagram of LiOH equilibrium was measured. The hydration and dehydration of LiOH at various conditions have been experimentally investigated. The results show that the steam diffusion can be greatly enhanced at vacuum condition. A thin layer of LiOH is uniformly dispersed in the reactor, which can greatly increase the heat transfer between the LiOH material and reactor, leading to a higher hydration reaction rate of LiOH. Furthermore, the steam pressure, reaction temperature, and the particle size of LiOH can greatly influence the hydration reaction. A maximum hydration reaction rate of 80% is obtained under the conditions of 47 °C, steam pressure of 9 kPa, and particle size of 32–40 μm. LiOH exhibits a different reaction property at the condition of pure steam without air and below atmospheric pressure. A store and reaction condition of LiOH with isolation of air is recommended when apply LiOH as a heat storage material at low temperature.

  • The effect of 3D carbon nanoadditives on Lithium Hydroxide monohydrate based composite materials for highly efficient low temperature thermochemical heat storage
    RSC Advances, 2018
    Co-Authors: Hongyu Huang, Noriyuki Kobayashi, Yugo Osaka, Haoran Yuan
    Abstract:

    Lithium Hydroxide monohydrate based thermochemical heat storage materials were modified with in situ formed 3D-nickel-carbon nanotubes (Ni-CNTs). The nanoscale (5–15 nm) LiOH·H2O particles were well dispersed in the composite formed with Ni-CNTs. These composite materials exhibited improved heat storage capacity, thermal conductivity, and hydration rate owing to hydrogen bonding between H2O and hydrophilic groups on the surface of Ni-CNTs, as concluded from combined results of in situ DRIFT spectroscopy and heat storage performance test. The introduction of 3D-carbon nanomaterials leads to a considerable decrease in the activation energy for the thermochemical reaction process. This phenomenon is probably due to Ni-CNTs providing an efficient hydrophilic reaction interface and exhibiting a surface effect on the hydration reaction. Among the thermochemical materials, Ni-CNTs–LiOH·H2O-1 showed the lowest activation energy (23.3 kJ mol−1), the highest thermal conductivity (3.78 W m−1 K−1) and the highest heat storage density (3935 kJ kg−1), which is 5.9 times higher than that of pure Lithium Hydroxide after the same hydration time. The heat storage density and the thermal conductivity of Ni-CNTs–LiOH·H2O are much higher than 1D MWCNTs and 2D graphene oxide modified LiOH·H2O. The selection of 3D carbon nanoadditives that formed part of the chemical heat storage materials is a very efficient way to enhance comprehensive performance of heat storage activity components.

  • Facile synthesis of graphene oxide-modified Lithium Hydroxide for low-temperature chemical heat storage
    Chemical Physics Letters, 2016
    Co-Authors: Xixian Yang, Hongyu Huang, Zhihui Wang, Mitsuhiro Kubota, Noriyuki Kobayashi
    Abstract:

    Abstract LiOH·H 2 O nanoparticles supported on graphene oxide (GO) were facilely synthesized by a hydrothermal process. The mean diameter of nanoparticles on the integrated graphene sheet was about 5⿿10 nm showed by SEM and TEM results. XRD results suggested that the nanoparticles are in good agreement with the data of LiOH·H 2 O. The as-prepared sample showed a greatly enhanced thermal energy storage density and exhibit higher rate of heat release than pure Lithium Hydroxide, and thermal conductivity of composites increased due to the introduction of nano carbon. LiOH·H 2 O/GO nanocomposites are novel chemical heat storage materials for potential highly efficient energy system.

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

  • surface treatment of rare earth magnesium nickel based hydrogen storage alloy with Lithium Hydroxide aqueous solution
    International Journal of Hydrogen Energy, 2015
    Co-Authors: Huiping Yuan, Kang Yang, Lijun Jiang, Xiaopeng Liu, Shumao Wang
    Abstract:

    Abstract The alkaline treatments of rare earth-magnesium–nickel based hydrogen storage alloy with Lithium Hydroxide (LiOH) aqueous solutions of various concentrations (1 M, 2 M, 4 M, 5 M, and 6 M) were investigated. The morphology and composition of the alloy surface and the electrochemical characters of the electrode were tested. The discharge capacity and cycle life of the alloy electrode were effectively improved after the treatment with LiOH solution of 5 M or higher. The samples treated in 5 M LiOH for 1 h and 6 M LiOH for 10 min showed better electrochemical properties than the other samples. The passive oxide and Hydroxide layer formed in LiOH solution increased the charge retention rate and decreased the high rate dischargeability of the alloy electrode. The high concentration LiOH solution diminished the formation of oxygen containing species on the alloy surface during the treatment. The LiOH solution can remove the Mg element on the alloy surface effectively.

  • Surface treatment of rare earth-magnesium–nickel based hydrogen storage alloy with Lithium Hydroxide aqueous solution
    International Journal of Hydrogen Energy, 2015
    Co-Authors: Yuan Huiping, Kang Yang, Lijun Jiang, Xiaopeng Liu, Shumao Wang
    Abstract:

    Abstract The alkaline treatments of rare earth-magnesium–nickel based hydrogen storage alloy with Lithium Hydroxide (LiOH) aqueous solutions of various concentrations (1 M, 2 M, 4 M, 5 M, and 6 M) were investigated. The morphology and composition of the alloy surface and the electrochemical characters of the electrode were tested. The discharge capacity and cycle life of the alloy electrode were effectively improved after the treatment with LiOH solution of 5 M or higher. The samples treated in 5 M LiOH for 1 h and 6 M LiOH for 10 min showed better electrochemical properties than the other samples. The passive oxide and Hydroxide layer formed in LiOH solution increased the charge retention rate and decreased the high rate dischargeability of the alloy electrode. The high concentration LiOH solution diminished the formation of oxygen containing species on the alloy surface during the treatment. The LiOH solution can remove the Mg element on the alloy surface effectively.

Masahiro Yoshimura - One of the best experts on this subject based on the ideXlab platform.

Kyoo-seung Han - One of the best experts on this subject based on the ideXlab platform.