2013年1月24日木曜日

2012年11月22日木曜日

I will post articles to “FuelCell japan-2”

Notice: I will post articles to “FuelCell japan-2” from now on, with some cause.
Fuelcell japan-2: http://fuelcelljapan-2.blogspot.jp/

2012年11月15日木曜日

Study of Polarization Effect and Thermal Stability in Aged Lithium-Ion Battery

Battery Safety 2012 December 6-7, 2012, Las Vegas, NV, USA
Advancements in System Design, Integration & Testing for Safety & Reliability

"Study of Polarization Effect and Thermal Stability in Aged Lithium-Ion Battery"- By Mahmood Tabaddor, PhD, Underwriters Laboratories
Research into the safety performance of lithium-ion cells has increased tremendously in recent years.
Field failures, though rare, may suggest that some failure mechanisms are dependent upon the state of the cell over a period of time, as such rechargeable sources of energy experience many charging and discharging cycles.
UL has hence proposed a project to investigate the safety performance in aged lithium-ion cells.
After a series of study, the polarization effect and the shift in the thermal properties in aged cells are found to be the major causes to safety concerns. >> More

Large Capacity L-ion Battery Technologies and Market Prospects

A book, entitled “Large Capacity L-ion Battery Technologies and Market Prospects”, has been recently published.
The major points discussed in the book are the following two.
1) The material technology and the battery technology are both described.
2) Market prospects of L-ion batteries for medium- and large-scale applications, including electric cars.
The lithium resource is plentiful in amount. Lithium is dangerous due to its nature of corrosive and explosive, however. It is an urgent desire to improve the technology to extract lithium from seawater containing an infinite amount of lithium particularly in Japan. The all-solid-state L-ion battery, which copes with the explosive, has been developed to a significant level. Further, the current social circumstance demanding use of clean energy requires acceleration of the research and development of the L-ion battery which stores and discharges electrical energy.
The L-ion battery is expanding its market to the market of medium- to large-scale L-ion batteries for automotive and industrial applications.
Vigorous efforts are focused on development of elemental technologies of L-ion battery such as electrodes and electrolyte, and materials used for them. >> More


2012年11月9日金曜日

"Characterizing Crash Safety of Cylindrical and Pouch Li-ion Batteries using Computational Modeling"

Battery Safety 2012 – December 6 – 7, LasVegas, NV
- Advancements in System Design, Integration & Testing for Safety & Reliability

"Characterizing Crash Safety of Cylindrical and Pouch Li-ion Batteries using Computational Modeling"- By Elham Sahraei, PhD and Tomasz Wierzbicki, PhD, Massachusetts Institute of Technology
Mechanical integrity
of Lithium-ion batteries is one of the most important issues on safety of electric cars, but the least studied topic.
As these batteries are not limited to stationary applications anymore, and are being used in vehicle battery packs, this aspect of their safety is more urgent to be characterized and quantified.
The automotive industry has realized that no battery pack could be rigid enough to ensure zero deformation to battery pack in severe enough crash conditions.
In this research, two common form factors of cylindrical and pouch batteries are characterized for several scenarios of deformation applied to these cells.
A comprehensive testing program was used to characterize the material properties of the cells under combined tension and predominantly compression and shear loading.

Then, computational models of the cells were developed.
The models successfully predict load-deformation trajectory and kinematics of the cell under various types of tests.
Additionally, the models are capable of predicting failure in the jelly-roll of the cell, indicating an internal short-circuit under mechanical deformation.
To compare the pouch and cylindrical cells tested in this research, the cylindrical cell tolerated a load of 5,500N and a deformation of about 7 mm before reaching short circuit,
while the pouch cell tolerated a load of 7,500N and a deformation of 3 mm before failure.
Predicting onset of electric short circuit is a necessary condition for possible thermal runaway.
>> More





L-ion battery monitor chip set for automotive-use L-ion batteries

A chip set has been used for monitoring L-ion battery conditions with the intention of securing battery safe and preventing battery performance deterioration. Toshiba is scheduled to commercialize a new chip set for monitoring L-ion battery conditions.
The new chip set is capable of detecting the residual amounts of battery capacities and troubles, and to equalize the capacity residual amounts of L-ion batteries being used.
The chip set = Monitor IC (TB9141FG) + TMPM358FDTFG (micro-controller) >> More

2012年11月8日木曜日

"High Energy Density Lithium Ion Batteries with Hetero-Hybrid Si/Ge-Carbon Nanotube Anodes"

Lithium Battery Power 2012(11) – December 4 – 5, LasVegas, NV

"High Energy Density Lithium Ion Batteries with Hetero-Hybrid Si/Ge-Carbon Nanotube Anodes"
By Brian J. Landi, PhD, Rochester Institute of Technology

Combined benefits of LPCVD (low pressure chemical vapor deposition ) or PECVD (plasma enhanced chemical vapor deposition) Si with Ge nanoparticles and carbon nanotube has led to an ultra high capacity anode (>1000 mAh/g electrode), along with enhanced coulombic efficiency.
Full batteries incorporating properly matched hetero-hybrid anodes with conventional cathodes shows cell improvements in gravimetric energy density over state-of-the-art by more than 50%

Recent significant innovations within lithium-ion batteries have propelled the technology into a position in the marketplace far exceeding recent market survey results. Breakthroughs in new battery chemistries, novel electrode and electrolyte materials, system integration for a vast array of mobile and portable applications, from micro medical devices to high-energy/high-power automotive, have paved the roadmap for an emerging market with unlimited potential.

* New chemistries & materials to increase energy & decrease cost
* Meeting the EV challenge: cycle life, power & energy, cost and safety
* Advanced materials for improved electrode & electrolyte performance
* Application driven lithium ion battery development
* Advanced technology for greater safety, reliability and performance
* From novel materials and components to systems design and integration
* Role of nanotechnology in improving power and energy density
>> More