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62. Intercalation/deintercalation of solvated Mg2+ into/from graphite interlayers.

Author

Shimizu, Masahiro, Nakahigashi, Atsuhito, and Arai, Susumu

Abstract

In the development of rechargeable Mg-ion batteries which are not limited by resource constraints, studies on negative electrode materials have been concentrated on efficient Mg-deposition/stripping rather than on insertion/extraction-type active materials, driven by the extremely high theoretical capacity of Mg metal (2205 mA h g−1). This work re-examined the potential of graphite, which is overlooked in electrochemical tests using a two-electrode type cell due to a large overpotential during sluggish Mg-deposition/stripping at the counter electrode caused by the passivation layer. The formation of a graphite intercalation compound (GIC) with a stage structure was demonstrated by the continual application of a constant current without considering the cut-off voltage to eliminate the detrimental impact of the counter electrode, although the intercalant was solvated Mg-ions. The GIC formed during the charging process has a blue tint just like a GIC synthesized by a vapor method. Although there is still issue with the large polarization during the deintercalation of solvated Mg ions, a reversible capacity of approximately 200 mA h g−1 could be achieved in the galvanostatic charge/discharge tests with a current density of 7.44 mA g−1. The results should facilitate future research and development of graphite as a negative electrode material. [ABSTRACT FROM AUTHOR]

Published
2021
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63. Hard Pure-Gold and Gold-CNT Composite Plating Using Electrodeposition Technique with Environmentally Friendly Sulfite Bath

Author

Arai, Susumu and Fujishige, Masatsugu

Subjects
Technology & Engineering / Materials Science
Abstract

Gold was used by Chinese and Egyptians of ancient times (at least ca 3000 BC). For many years, gold based materials have received great attention from people, due to the good conductor, high chemical stability, unique optical and processable properties. Electrodeposition technology is a long established technique for synthesizing metals on conductive substrates. Advances in equipment and creations of nanomaterials could carry out new technological progress, a large duty ratio with a pulse overvoltage became possible and new composite fillers (for example, carbon nanotubes: CNTs) appeared. Moreover, environmental considerations have become more important as Sustainable Development Goals (SDGs). SDGs were adopted at the United Nations Summit in September 2015 and are the goals set by the 193 member countries to achieve in the 15 years from 2016 to 2030. For the global environment and workers, friendly manufacturing methods have become more important. In this chapter, two nanostructured golds (hard pure-gold plating and gold-CNT composite plating) are discussed. They are a method of hardening the metal as pure-gold by pulsed electrodeposition and a method of combining CNT by controlling the zeta potential with additives, and their application as a contact material was investigated. Additionally, the synthesis and characteristics of electrostatic deposition films with properties using environmentally friendly sulfite bath are discussed.

Published
2018

72. Hard Pure-Gold and Gold-CNT Composite Plating Using Electrodeposition Technique with Environmentally Friendly Sulfite Bath

Author

Fujishige, Masatsugu, Arai, Susumu, Fujishige, Masatsugu, and Arai, Susumu

Abstract

Gold was used by Chinese and Egyptians of ancient times (at least ca 3000 BC). For many years, gold based materials have received great attention from people, due to the good conductor, high chemical stability, unique optical and processable properties. Electrodeposition technology is a long established technique for synthesizing metals on conductive substrates. Advances in equipment and creations of nanomaterials could carry out new technological progress, a large duty ratio with a pulse overvoltage became possible and new composite fillers (for example, carbon nanotubes: CNTs) appeared. Moreover, environmental considerations have become more important as Sustainable Development Goals (SDGs). SDGs were adopted at the United Nations Summit in September 2015 and are the goals set by the 193 member countries to achieve in the 15 years from 2016 to 2030. For the global environment and workers, friendly manufacturing methods have become more important. In this chapter, two nanostructured golds (hard pure-gold plating and gold-CNT composite plating) are discussed. They are a method of hardening the metal as pure-gold by pulsed electrodeposition and a method of combining CNT by controlling the zeta potential with additives, and their application as a contact material was investigated. Additionally, the synthesis and characteristics of electrostatic deposition films with properties using environmentally friendly sulfite bath are discussed.

Published
2018
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80. Communication-Micro-Scale Columnar Architecture Composed of Copper Nano Sheets by Electrodeposition Technique

Author

Arai, Susumu, Ozawa, Masaya, Shimizu, Masahiro, Arai, Susumu, Ozawa, Masaya, and Shimizu, Masahiro

Abstract

Micro-scale columnar architectures composed of copper sheets with nanometer thickness were fabricated by electrodeposition using a photolithography technique. A copper sulfate solution containing a polyacrylic acid was used as the plating bath, and the electrodeposition was conducted under galvanostatic conditions. Patterned electrodeposits with a cylindrical shape and composed of thin copper sheets were formed. Every copper deposit had openings on the top and side regions and also had a porous interior. This novel three-dimensional (3D) copper architecture should provide functional copper electrodes with large effective surface areas. (C) The Author(s) 2016. Published by ECS. All rights reserved., Article, JOURNAL OF THE ELECTROCHEMICAL SOCIETY. 164(2):D72-D74 (2017)

Published
2017

81. 表面技術に見る夢

Author

Arai, Susumu, Ueda, Mikito, Ogai, Takeshi, GamoNishitani, Mika, Murase, Kuniaki, Yae, Shinji, and Matsubara, Hiroshi

Published
2011

82. Cu-MWCNT Composite Films Fabricated by Electrodeposition

Author

Arai, Susumu, Saito, Takashi, and Endo, Morinobu

Subjects
internal stresses, current density, carbon nanotubes, electrical conductivity, metallic thin films, materials preparation, hardness, copper, nanocomposites, electrodeposition, nanofabrication, surface morphology, thermal conductivity, electrical resistivity
Abstract

Copper–multiwalled carbon nanotube (MWCNT) composite plating using a sulfuric base bath was studied. A dispersing agent was used to disperse the MWCNTs into the plating bath. The effects of electrodeposition conditions on the surface morphology, microstructure, and MWCNT content in the composite films were examined. The internal stress, hardness, electrical conductivity, and thermal conductivity of the composite films were also investigated. The current density remarkably affected the surface morphologies of the films, and a relatively smooth surface was obtained at lower current densities. The bath temperature affected the microstructure of the composite films; a compact microstructure was formed at a lower temperature. The MWCNT content in the composite film increased with increasing MWCNT concentration in the plating bath, reaching a maximum value of 0.55 mass %. However, MWCNTs in the composite films tended to agglomerate for high MWCNT concentrations in the plating bath. An internal tensile stress was induced in the films. The hardness of the films was around 150 HV, and the electrical resistivity was approximately 2–2.5μΩ cm. The thermal conductivity of the Cu–0.42 mass % MWCNT composite film was 355 W m⁻¹ K⁻¹., Article, JOURNAL OF THE ELECTROCHEMICAL SOCIETY

Published
2010

83. Boron Particle Composite Plating with Ni-B Alloy Matrix

Author

Arai, Susumu, Kasai, Shuji, and Shohji, Ikuo

Subjects
current density, amorphous state, heat treatment, composite materials, electrodeposition, metallic thin films, nickel alloys, materials preparation, boron alloys, hardness
Abstract

Ni–B alloy films containing amorphous boron particles (referred to as “Ni–B alloy composite films”) were fabricated by electrodeposition and were subsequently subjected to heat-treatment. Their compositions and microstructures were characterized, and their hardness was evaluated. The content of boron particles in the alloy composite films increased with boron particle concentration in the plating baths. In addition, the total boron content in the films increased with decreasing current density, reaching a maximum value of 34.3 atom %. The boron particles were homogeneously distributed in these alloy composite films and exhibited no cohesion. Heat-treatment of the alloy composite films consisting of a Ni–B alloy matrix and the boron particles led to a phase conversion from an inhomogeneous amorphous phase to stable homogeneous crystalline phases, which were similar to those in the Ni–B binary alloy phase diagram. The hardness of the Ni–B alloy 34.3 atom % B composite film was higher than that of a Ni–B alloy film both before and after heat-treatment., Article, JOURNAL OF THE ELECTROCHEMICAL SOCIETY. 157(2):D119-D125 (2010)

Published
2009

84. Phosphorus Particle Composite Plating with Ni-P Alloy Matrix

Author

Suzuki, Yosuke, Arai, Susumu, Shohji, Ikuo, and Kobayashi, Eiji

Subjects
technology, industry, and agriculture, equipment and supplies
Abstract

Ni-P alloy films containing phosphorus particles (called Ni-P alloy composite films) were fabricated by electrodeposition and were subsequently subjected to heat-treatment. Their compositions and microstructures were characterized, and their friction properties were evaluated using a ball-on-plate method. Composite electroplating in the nickel sulfate and chloride bath containing phosphorus acid and micrometer-sized phosphorus particles resulted in the Ni-P alloy coating with enhanced deposit phosphorus content. The phosphorus content of the films increased with increasing phosphorus particle concentration in the composite plating baths, reaching a maximum value of 29.0 atom %. The phosphorus particles were homogeneously distributed in this Ni- 29.0 atom % P alloy composite film. Heat-treatment converted the phases of the alloy composite films from an amorphous phase to stable crystalline phases, which are the same as those in the Ni- P binary alloy phase diagram. The friction coefficients of the Ni- P alloy films increased with increasing cycle number, whereas those of the Ni- P alloy composite films remained relatively constant. The alloy composite films had lower friction coefficients than the Ni- P alloy films both before and after heat-treatment. These results indicate that phosphorus particles are beneficial for maintaining a lower and stable friction coefficient during the ball-on-plate reciprocating friction test., Article, JOURNAL OF THE ELECTROCHEMICAL SOCIETY 156: D283-D286(2009)

Published
2009

89. Design of Roughened Current Collector by Bottom-up Approach Using the Electroplating Technique: Charge–Discharge Performance of a Sn Negative-Electrode for Na-Ion Batteries

Author

Shimizu, Masahiro, Yatsuzuka, Ryosuke, Horita, Masaomi, Yamamoto, Takahiro, and Arai, Susumu

Abstract

The use of high capacity electrode materials based on alloying and dealloying reactions with Na is very effective for improving energy density of batteries. However, their application brings on electrical isolation such as detachment of the electrode mixture layer from a current collector, causing rapid capacity fading. We previously found that Cu electrochemically grows in sheet form by electroplating in a CuSO4-based aqueous solution with poly(acrylic acid) (PAA). In the present study, our goal was to elucidate the formation mechanism of Cu sheets by characterization using scanning transmission electron microscopy (STEM), X-ray diffraction (XRD) analysis, and electron scatter diffraction patterns (EBSD) mapping. Then, the cycling performance of a Sn negative electrode for Na-ion batteries was significantly upgraded by the application of a roughened-Cu substrate with optimized sheet thickness. The STEM images and EBSD maps revealed that the Cu sheet was a single crystal, and the results obtained from XRD and the cathodic polarization behavior of Cu electrodeposition in PAA-containing solutions suggested that PAA molecules adsorbed onto Cu (100) to suppress the Cu growth on the plane, resulting in the formation of Cu sheets. Although the initial reversible capacities of flat-Cu/Sn and roughened-Cu/Sn electrodes were comparable, the developed Cu substrate (1.0 × 10–4M PAA) delivered a noticeable increase in the reversible capacity by 210 mA h g–1from the first to the second cycle, whereas the flat-Cu remained the increase by 100 mA h g–1. In addition, the roughened-Cu substrate suppressed the detachment of the active material layer to maintain a high capacity of 685 mA h g–1with good capacity retention of more than 90% by the anchor effect. These results demonstrate that the roughened-Cu substrate prepared in the present work is a promising candidate as a current collector for rechargeable batteries.

Published
2024
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90. Fabrication of Three-Dimensional (3D) Copper/Carbon Nanotube Composite Film by One-Step Electrodeposition

Author

Arai, Susumu, Ozawa, Masaya, Shimizu, Masahiro, Arai, Susumu, Ozawa, Masaya, and Shimizu, Masahiro

Abstract

A three-dimensional (3D) composite film containing copper nanostructures and carbon nanotubes (3DC/CNT composite film) was fabricated by one-step electrodeposition. The 3DC/CNT composite film was formed under galvanostatic conditions using a copper sulfate bath containing CNTs and polyacrylic acid which acts as both a 3DC-forming and a CNT-dispersing agent. The composite film consists of thin copper sheets with thicknesses of ca. 70-80 nm and CNTs, with large interior spaces between sheets. The CNTs were homogeneously distributed inside the composite film and were fixed by the copper sheets where CNTs pierce the copper sheets. The CNT content in the composite films increased with the CNT concentration of the plating bath. The 3DC film without CNTs did not maintain its 3D spaces when the film thickness was increased due to insufficient structural strength, whereas the 3DC/CNT composite film maintained the 3D spaces despite an increase in film thickness, which suggests that the CNTs reinforce the film to maintain the 3D spaces. (C) The Author(s) 2016. Published by ECS. All rights reserved., Article, JOURNAL OF THE ELECTROCHEMICAL SOCIETY. 163(14):D774-D779 (2016)

Published
2016

91. Communication-Fabrication of a Uniformly Tin-Coated Three-Dimensional Copper Nanostructured Architecture by Electrodeposition

Author

Arai, Susumu, Mendsaikhan, Munkhbat, Nishimura, Koichi, Arai, Susumu, Mendsaikhan, Munkhbat, and Nishimura, Koichi

Abstract

A three-dimensional copper nanostructure architecture (3DC1) coated uniformly with a tin film was fabricated by electrodeposition. In these trials, a pyrophosphate bath was used for tin plating, and the effects of polyethylene glycol and formaldehyde additives on the morphology of the deposited tin were investigated. Relatively large tin particles were electrodeposited in an inhomogeneous manner over the 3DC1 surface when using a plating bath without additives. In contrast, 3DC1 coated with a uniformly thick tin film was fabricated by employing a bath with the additives. (C) The Author(s) 2015. Published by ECS., Article, JOURNAL OF THE ELECTROCHEMICAL SOCIETY. 163(2):D54-D56 (2016)

Published
2016

100. Fabrication of Copper/Multiwalled Carbon Nanotube Composites Containing Different Sized Nanotubes by Electroless Deposition

Author

Arai, Susumu, Osaki, Takuma, Arai, Susumu, and Osaki, Takuma

Abstract

Cu/multiwalled carbon nanotube(MWCNT) composites containing two different sized MWCNTs were fabricated using an electroless deposition technique in aqueous solution. In order to disperse the MWCNTs in the solution, an anionic dispersant of sodium dodecyl sulfate (SDS) and a polymeric dispersant of hydroxypropyl cellulose (HPC) were used. The dispersibility of the MWCNTs in solution was evaluated by measuring the particle size distribution. The zeta potential for the MWCNTs was also evaluated to examine the dispersibility. Uniform Cu/MWCNT composites containing the two different sized MWCNTs were fabricated through the electroless copper deposition process from a solution containing copper ions, a complexing agent, a reducing agent, and two dispersants, SDS and HPC, in addition to the two different sized MWCNTs. (C) The Author(s) 2014. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited. All rights reserved., Article, JOURNAL OF THE ELECTROCHEMICAL SOCIETY. 162(1):D68-D73 (2015)

Published
2015

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