Tag Archives: NEC

NEC and its ‘carbon nanobrush’

Long associated with the discovery of carbon nanotubes (CNTs), NEC Corporation has announced another carbon material, carbon nanobrushes, in a July 7, 2016 news item on phys.org,

NEC Corporation today [June 30, 2016] announced the discovery of a new nano carbon material, the “carbon nanobrush,” a fibrous aggregate of single-walled carbon nanohorns. Moreover, NEC has become the first company in the world to manufacture the carbon nanobrush.

A June 30, 2016 NEC Corporation press release, which originated the news item, provides more detail (Note: This excerpt has been reformatted for clarity),

“The ‘carbon nanobrush’ is a new nano carbon material that, like existing carbon nanohorns, has high water and solvent dispersity, and high adsorptivity, including substance adsorption, but has more than 10 times the electrical conductivity than existing carbon nanohorns, an important characteristic for industrial applications,” said Dr. Sumio Iijima, Senior Research Fellow, NEC Corporation. “With these characteristics, it is anticipated that the carbon nanobrush will help to improve the basic functionality of a range of devices, including increasing the speed of sensor and actuator responses, improving the output properties of batteries and capacitors, while increasing the electrical conductivity of rubber and plastic composite materials, as well as having application in a wide range of industries.”

1. TEM images of the obtained samples

2. Tips of single-walled carbon nanohorn

3. Spherical-carbon nanohorn aggregates

Carbon nanohorns are horn-shaped (figure 2) nano carbon structures 2-5 nanometers (nm) in diameter and 40-50nm in length, which until now have been produced as radial spherical aggregates (figure 3). The newly discovered carbon nanobrush is a uniquely shaped material. It is fibrous aggregates composed of radially-assembled graphene-based single-walled nanotubules, named here as fibrous aggregates of single-walled carbon nanohorns, whose structure resembles that of a round brush (figure 1).

Features of the “carbon nanobrush” include the following:

    1. Structure
      (1)Single-walled carbon nanohorns of 2-5nm in diameter and 40-50nm in length radially gather and are connected fibrously in several micrometers.
      (2)The single-walled carbon nanohorn which is a horn-shaped nano carbon structure with a large surface area radially gather and are connected fibrously in several micrometers. So it has a large surface area per unit mass (up to 1700㎡/g).
    1. Characteristics
      Like carbon nanohorns, the carbon nanobrush has high dispersibility, dispersing in water and organic solvents, for example. This means that it can be easily mixed with a variety of materials, making it easy to improve its characteristics as a base material.(2)Adsorptivity
      Like spherical carbon nanohorns, the carbon nanobrush can contain various substances in the nano-sized spaces inside the tubular structure, so it can be utilized as a high-performance adsorbent. When holes are formed on the surface of the carbon nanohorns by oxidation treatments, the inner space can be used, expanding the surface area by a factor of approximately five and greatly increasing adsorptivity.

      (3)Electrical conductivity
      As carbon nanobrush is a fibrous aggregate of radially-assembled carbon nanohorns, it has more than 10 times the electrical conductivity compared with existing spherical carbon nanohorn aggregates. As a result, they are highly effective in increasing the speed of sensor and actuator responses, increasing output properties of batteries and capacitors, and increasing the electrical conductivity of rubber and plastic composite materials.

  1. Production process
    Carbon nanobrush can be produced at room temperature and under atmospheric pressure using the laser ablation method where an iron-containing carbon target (mass of carbon) is irradiated by a laser with high power density. The simple production process means that they can be produced efficiently and at a low cost when compared to the cost of other nano carbon materials.

This technology was developed in part through collaborative research with the National Institute of Advanced Industrial Science and Technology (AIST).

Here’s a link to and a citation for the paper,

Preparation and Characterization of Newly Discovered Fibrous Aggregates of Single-Walled Carbon Nanohorns by Ryota Yuge, Fumiyuki Nihey, Kiyohiko Toyama, and Masako Yudasaka. Advanced Materials DOI: 10.1002/adma.201602022 Version of Record online: 25 MAY 2016

© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

For anyone interested in a history of carbon nanotubes, there’s my June 10, 2016 posting: The birth of carbon nanotubes (CNTs): a history, which includes a mention of NEC and its position as the discoverer of carbon nanotubes.

The birth of carbon nanotubes (CNTs): a history

There is a comprehensive history of the carbon nanotube stretching back to prehistory and forward to recent times in a June 3, 2016 Nanowerk Spotlight article by C.K. Nisha and Yashwant Mahajan of the Center of Knowledge Management of Nanoscience & Technology (CKMNT) in India. The authors provide an introduction explaining the importance of CNTs,

Carbon nanotubes (CNTs) have been acknowledged as the material of the 21st century. They possess unique combination of extraordinary mechanical, electronic, transport, electrical and optical, properties and nanoscale sizes making them suitable for a variety of applications ranging from engineering, electronics, optoelectronics, photonics, space, defence industry, medicine, molecular and biological systems and so on and so forth. Worldwide demand for CNTs is increasing at a rapid pace as applications for the material are being matured.

According to MarketsandMarkets (M&M), the global market for carbon nanotubes in 2015 was worth about $2.26 billion1; an increase of 45% from 2009 (i.e. ~ $ 1.24 billion). This was due to the growing potential of CNTs in electronics, plastics and energy storage applications and the projected market of CNTs is expected to be around $ 5.64 billion in 2020.

In view of the scientific and technological potential of CNTs, it is of immense importance to know who should be credited for their discovery. In the present article, we have made an attempt to give a glimpse into the discovery and early history of this fascinating material for our readers. Thousands of papers are being published every year on CNTs or related areas and most of these papers give credit for the discovery of CNTs to Sumio Iijima of NEC Corporation, Japan, who, in 1991, published a ground-breaking paper in Nature reporting the discovery of multi-walled carbon nanotubes (MWCNTs)2. This paper has been cited over 27,105 times in the literature (as on January 12, 2016, based on Scopus database). This discovery by Iijima has triggered an avalanche of scientific publications and catapulted CNTs onto the global scientific stage.

Nisha and Mahajan then prepare to take us back in time,

In a guest editorial for the journal Carbon, Marc Monthioux and Vladimir L. Kuznetsov3 have tried to clear the air by describing the chronological events that led to the discovery of carbon nanotubes. As one delves deeper into the history of carbon nanotubes, it becomes more apparent that the origin of CNTs could be even pre-historic in nature.

Recently, Ponomarchuk et al from Russia have reported the presence micro and nano carbon tubes in igneous rocks formed about 250 million years ago4-7. They suggested the possibility of formation of carbon nanotubes during the magmatic processes. It is presumed that the migration of hydrocarbon fluids through the residual melt of the rock groundmass created gas-saturated areas (mostly CH4, CO2, CO) in which condensation and decomposition of hydrocarbon in presence of metal elements resulted in the formation of micro and sub-micron carbon tubes.

Another most compelling evidence of pre-historic naturally occurring carbon nanotubes (MWCNTs) is based on the TEM studies carried out by Esquivel and Murr8 that analyzed 10,000-year-old Greenland ice core samples and it was suggested that probably they could have been formed during combustion of natural gas/methane during natural processes.

However, the validity of this evidence is questionable owing to the lack of clear high-resolution TEM images, high-quality diffraction patterns or Raman spectroscopy data. In addition, [an]other interesting possibility is that the carbon nanotubes could have been directly formed by the transformation of naturally occurring C60 fullerenes in nature without the assistance of man, given the right conditions prevail. Suchanek et al.,9 have actually demonstrated this thesis, under the laboratory environment, by transforming C60 fullerenes into CNTs under hydrothermal conditions.

There is a large body of evidence in literature about the existence of naturally occurring fullerenes in nature, e.g., coal, carboneous rocks, interstellar media, etc. Since the above experiments were conducted under the simulated geological environment, their results imply that CNTs may form in natural hydrothermal environment.

This hypothesis was further corroborated by Velasco-Santos and co-workers10, when they reported the presence of CNTs in a coal–petroleum mix obtained from an actual oil well, identified by the PEMEX (the Mexican Petroleum Company) as P1, which is located in Mexico’s southeast shore. TEM studies revealed that the coal-petroleum mix contained predominantly end-capped CNTs that are nearly 2 µm long with outer diameter varying between few to several tenths of nanometers.

There’s another study supporting the notion that carbon nanotubes may be formed naturally,

In yet another study, researchers from Germany11 have synthesized carbon nanotubes using igneous rock from Mount Etna lava as both support and catalyst. The naturally occurring iron oxide particles present in Etna lava rock make it an ideal material for growing and immobilizing nanocarbons.

When a mixture of ethylene and hydrogen were passed over the pulverized rocks reduced in a hydrogen atmosphere at 700°C, the iron particles catalyzed the decomposition of ethylene to elemental carbon, which gets deposited on the lava rock in the form of tiny tubes and fibers.
This study showed that if a carbon source is available, CNTs/CNFs can grow on a mineral at moderate temperatures, which directs towards the possibilities of carbon nanotube formation in active suboceanic volcanos or even in interstellar space where methane, atomic hydrogen, carbon oxides, and metallic iron are present.

This fascinating and informative piece was originally published in the January 2016 edition of Nanotech Insights (CKMNT newsletter; scroll down) and can be found there although it may be more easily accessible as the June 3, 2016 Nanowerk Spotlight article where it extends over five (Nanowerk) pages and has a number of embedded images along with an extensive list of references at the end.


Wanxiang America wins bid for most of A123 Systems’ assets

The A123 Systems, Inc., a manufacturer of lithium-ion (Li-ion) batteries, story takes a few more twists and turns. The company declared bankruptcy in Oct. 2012 and announced that it had entered an asset purchase agreement with Johnson Controls. From the A123 Systems About Us webpage,

Asset Purchase Agreement and Chapter 11 Information

On October 16, 2012, A123 Systems, Inc. announced that it has entered into an asset purchase agreement with Johnson Controls, Inc., which plans to acquire A123’s automotive business assets, including all of its automotive technology, products and customer contracts, its facilities in Livonia and Romulus, Mich., its cathode powder manufacturing facilities in China, and A123’s equity interest in Shanghai Advanced Traction Battery Systems Co., Alpha’s joint venture with Shanghai Automotive. The asset purchase agreement also includes provisions through which Johnson Controls intends to license back to A123 certain technology for its grid, commercial and government businesses.

Today, Dec. 10, 2012, there’s a news item on Azonano about A123 Systems’ assets being acquired by Wangxiang America,

A123 Systems, Inc., a developer and manufacturer of advanced Nanophosphate® lithium iron phosphate batteries and systems, today announced that it has reached agreement on the terms of an asset purchase agreement with Wanxiang America Corporation (“Wanxiang”) through which Wanxiang would acquire substantially all of A123’s assets for $256.6 million.

The agreement was reached following an auction conducted under the supervision of the United States Bankruptcy Court for the District of Delaware (the “Court”). A hearing at which A123 and Wanxiang will seek the required Court approval of the sale is scheduled for Tuesday, December 11, 2012.

According to the terms of the asset purchase agreement, Wanxiang would acquire A123’s automotive, grid and commercial business assets, including all technology, products, customer contracts and U.S. facilities in Michigan, Massachusetts and Missouri; its cathode powder manufacturing operations in China; and its equity interest in Shanghai Advanced Traction Battery Systems Co., A123’s joint venture with Shanghai Automotive. Excluded from the asset purchase agreement with Wanxiang is A123’s Ann Arbor, Mich.-based government business, including all U.S. military contracts, which would be acquired for $2.25 million by Navitas Systems, a Woodridge, Ill.-based provider of energy-enabled system solutions and energy storage products for commercial, industrial and government agency customers.

The Oct. 2012 deal with Johnson Controls seems to have collapsed, which occasioned this December 2012 auction in which Johnson Controls did participate initially. From the Dec. 9, 2012 Johnson Controls news release on PR Newswire,

Johnson Controls officially withdrew from the bankruptcy auction to acquire portions of A123 Systems when it declined to match a higher bid submitted by Wanxiang.  Subsequently A123 representatives have announced they selected Wanxiang’s bid of $257 million as the best offer for the total company over a set of competing complementary bids by Johnson Controls for the automotive and government assets and NEC for the grid and commercial assets.

“While A123’s automotive and government assets were complementary to Johnson Controls’ portfolio and aligned with our long-term goals, Wanxiang’s offer was beyond the value of those assets to Johnson Controls,” said Alex Molinaroli, president, Johnson Controls Power Solutions. “Reports by other parties that our proposal involved an elimination of jobs in Michigan are inaccurate.”

The Dec. 10, 2012 news article on Bloomberg Businessweek website provides more detail and some analysis,

Wanxiang is seeking A123’s battery technology, used in Fisker Automotive Inc.’s Karma sedan, as China pushes its companies to develop electric vehicles. An earlier accord with the Chinese company was scrapped in October, when A123 said it filed for bankruptcy protection and agreed to sell its automotive assets to Johnson Controls.

“The purchase of A123 would automatically vault Wanxiang to become probably the number one battery maker in China,” said Shu Sun, a Beijing-based analyst at Bloomberg New Energy Finance. “Technology-wise, no battery company in China is likely to match A123’s products in performance and reliability.”

A123 supplies electric-car batteries to a dozen customers, according Bloomberg New Energy Finance estimates. That’s the highest number of clients in the industry, though LG Chem Ltd. and NEC Corp. (6701)’s venture with Leaf-maker Nissan Motor Co. have higher volume sales, Sun said.

Wanxiang Qianchao Co. (000559), a listed unit of the closely held parent advanced 1.4 percent to 4.25 yuan in Shenzhen trading today, narrowing its loss for the year to 25 percent.

The auction results also pave the way for Hangzhou, China- based Wanxiang to receive A123’s cathode powder plant in China and its share of a joint venture with Shanghai Automotive Industry Corp. called Shanghai Advanced Traction Battery Systems Co., according to yesterday’s statement.

Navitas Systems, a Woodridge, Illinois-based company, will buy A123’s Ann Arbor, Michigan-based government business for $2.25 million, according to the statement.

A123, the recipient of a $249.1 million federal grant, held the auction behind closed doors in the Chicago law offices of Latham & Watkins. The auction began on Dec. 6 with prospective bidders including Johnson Controls, Wanxiang, Siemens AG (SIE) of Germany and Tokyo-based NEC Corp.

As to the why and how of A123 Systems’ bankruptcy in the first place, Dexter Johnson in his Oct. 17, 2012 posting on Nanoclast (on the IEEE [Institute of Electrical and Electronics Engineers] website) suggests it had to do with old fashioned supply and demand economics,

The underlying problems of A123 Systems, Solyndra, and Konarka are not political ones of governmental policies—they’re illustrations of the futility of ignoring good old-fashioned supply-and-demand economics. (Solyndra, besides never being competitive with traditional energy sources, was also forced to compete with heavily subsidized solar alternatives.)

There is little question that A123 Systems made a better Li-ion battery than its competitors. The problem was the nano-enabled battery that they came up with for powering electric vehicles (EVs) was not in competition with other Li-ion batteries, but with the internal combustion engine.

This is not a political issue or an ideological issue, it’s a numbers issue. …

Dexter mentions A123 Systems again in an Oct. 19, 2012 posting (Nanotechnology As Socio-Political Project), featuring a broader analysis of the issues around commercializing technologies. There’s a thesis in here for someone.

ETA Dec. 13, 2012: The US Bankruptcy Court for the District of Delaware has approved the sale of A123 Systems’ military business to Navitas according to a Dec. 13, 2012 news item on Azonano,

Navitas Systems LLC, a leading provider of energy-enabled system solutions and energy storage products for commercial, industrial and government agency customers, today announced that the United States Bankruptcy Court for the District of Delaware (the “Court”) has approved the sale of A123 Systems’ Ann Arbor, Mich.-based government business, including all U.S. military contracts, for $2.3 million to Navitas. …

Navitas Systems can be found here.