Batteries That Heal Themselves

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

Alert reader Colin Rush provided this breaking development in battery science. Regular readers will remember Dr. Yi Cui’s name.  He’s a Stanford University scientist who has worked with paper batteries, much more powerful electrodes, and means of helping batteries stay together under the continuous strain of expanding and contracting during charging and discharging.  He explained that at the third annual Electric Aircraft Symposium at the Hiller Aviation Museum, and has since adopted several tactics to overcome that problem.  One commercial outgrowth of his work, Amprius, is working on commercial production that benefits from his insights. Since that internal flexing eventually leads to cracking of electrodes, Dr. Cui’s latest announcement brings some hope that such things can not only be overcome, …

Breaking Up Isn’t So Hard to Do

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

A great deal of the research on lithium batteries goes into figuring out how to keep them together for the greatest number of charge-discharge cycles.   Unfortunately, the active compounds in these batteries that give the greatest energy storage capacity or power output, also tend to be those compounds that come unglued under stress. Taking high-resolution 3D movies with X-ray tomography (somewhat like the CAT scans used on human subjects), researchers at the Swiss Light Source, a mecca for seeing the unseeable, have witnessed the expansion and contraction of the internal structure of lithium-ion batteries, while the batteries are operating. Stanford University’s Dr. Cui has explained that the expansion and contraction of batteries leads to their eventual failure, but until now, …

Lithium Gets a Good Wrap

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

Shadi Dayeh, professor in the Department of Electrical and Computer Engineering at the UC San Diego Jacobs School of Engineering, has been designing new electrode architectures that could solve one of lithium batteries’ biggest problems.  When lithium diffuses across the surface of a lithium-ion battery electrode, it causes the electrode to expand and contract depending on its charging or discharging.  This eventually leads to cracking and ultimate disintegration of the anode or cathode – weakening and finally disabling the battery. Dayeh, working with colleagues at the University and Sandia and Los Alamos National Laboratories, came up with nanowires that, “Block diffusion of lithium (Li) across their silicon surface and promote layer-by-layer axial lithiation of the nanowire’s germanium core.” Seeing possibilities …

A Milestone on the Road to Dr. Cui’s 10X Battery

Dean Sigler Electric Powerplants, Sustainable Aviation 1 Comment

Seeing the Amprius web site, one would never know that some “dramatic improvements” promised in the terse announcement might mean so much in terms of true breakthroughs. Neatly centered, Amprius’ total web site is a few  lines of discrete text. Amprius is a leading Lithium-Ion battery developer Amprius’s silicon technology was originally developed at Stanford University and enables dramatic improvements in the energy density and specific energy of Lithium-Ion batteries. Amprius is backed by some of the world’s leading investors, including Trident Capital, VantagePoint Venture Partners, IPV Capital, Kleiner Perkins Caufield & Byers, and Dr. Eric Schmidt. Amprius, Inc., 225 Humboldt Ct. Sunnyvale, CA 94089 But the battery manufacturer has two first-generation product offerings with volumetric energy densities of 580 …

That’s No Yolk!

Dean Sigler Electric Powerplants, GFC, Sustainable Aviation 0 Comments

Dr. Cui is at it again!  In a seemingly endless stream of announcements, his work with silicon anodes keeps promising improvements in battery capacity and longevity.  The Stanford professor and his team, Stanford’s National Accelerator Laboratory (Formerly the Stanford Linear Accelerator Center), and the Environmental Molecular Sciences Laboratory (EMSL) at Pacific Northwest National Laboratory all published papers on their latest joint accomplishment. Conceptual drawing of silicon filling carbon shell, TEM photo of actual expansion, and life cycle analysis for yolk-shell batteries Expansion and contraction of anodes and cathodes during charging and discharging of batteries causes flexing and eventual breakdown of a battery’s internal components.  Cui and other researchers have tried various strategies to mitigate or eliminate this flexing, but the …

Dipping and Coating for Better Batteries

Dean Sigler Electric Powerplants, Sustainable Aviation 1 Comment

Could dipping electrodes in a secret sauce improve supercapacitor and battery endurance and power?  Could coating cell internals be the flavor of the month?  These recipes for better batteries may improve things at a better than normal rate, if California researchers have anything to say about it. Working with his compatriot Dr. Jaephil Cho in South Korean, Dr. Cui of Stanford University has been a leader in developing improved battery technology, even developing a painted paper battery.  In an appearance at the 2009 Electric Aircraft Symposium, Cui explained a basic truth of battery development – that improvements generally created about eight percent greater power or endurance in cells every year, leading to a doubling of battery capabilities every seven and one-half …

Power Spraying Takes on a Whole New Meaning

Dean Sigler Electric Powerplants, Sustainable Aviation 4 Comments

Several news sources, apparently using the same press release from Mitsubishi Chemical Corp., have announced a spray-on solar cell, which can be applied in the same fashion as paint – to “buildings, vehicles and even clothing.”  This “means that the places where energy from the sun can be harvested are almost limitless.” Less than one millimeter thick and capable of 10.1-percent efficiency, the new material is said to have a weight one-tenth of traditional silicon cells.  Mitsubishi says these are prototype materials, and that they hope to achieve 15-percent efficiency by 2015, with 20 percent as a more distant possibility. Mitsubishi is a bit soft on details, but says, “The new solar cells utilize carbon compounds which, when dried and solidified, …

Dr. Jaephil Cho’s Powerful Silicon Nanotubes

Dean Sigler Sustainable Aviation 1 Comment

Shortly before appearing at the fourth Annual Electric Aircraft Symposium at Rohnert Park, California, Dr. Jaephil Cho was interviewed by Esther Levy of Material Views, an online resource dealing with, as the title implies, high-technology materials.  Dr. Cho, Dean of the new Interdisciplinary School of Green Energy at Ulsan National Institute of Science & Technology (UNIST), works with lithium-ion cells, and along with Dr. Yi Cui of Stanford University, is considered among the most forward thinking researchers in the field. Where Dr. Cui’s efforts are related to development of better cathodes, Dr. Cho’s work focuses on improving anode performance. Their efforts have led to an 80-percent improvement in cathode performance, as reported in Dr. Cui’s presentation at EAS III, and …

Half a World Apart, United in Their Research

Dean Sigler Uncategorized 0 Comments

Dr. Yi Cui, a winner of the 2004 MIT Technology Review World Top 100 Young Innovator Award (among other notable awards), and Assistant Professor in the Department of Materials Science and Engineering at Stanford University, was a distinguished presenter at the CAFE Foundation’s Third Annual Electric Aircraft Symposium last April. He talked about the structure and manufacturing of lithium-ion cells, and the material limitations placed on the performance of those cells. His breakthrough in using nanowires in the cathode promises an 80-percent gain in the cell’s charge-holding ability, equivalent to ten years of the normal cell improvement of eight percent per year. The good news was somewhat of a letdown for many, who were hoping to hear of a total …

The Painted Battery

Dean Sigler Uncategorized 0 Comments

Dr. Yi Cui, assistant professor of materials science and engineering at Stanford University, is a battery scientist extraordinaire, and a presenter at last April’s Third Annual Electric Aircraft Symposium. His paper was well received, one in which he discussed how breakthroughs in his lab could lead to an 80-percent improvement in battery capacity for the same weight as current units. He has topped himself with an extraordinary approach to manufacturing batteries. Imagine painting an ordinary piece of paper with a coating of carbon nanotubes and silver nanowires, and ending up with a very thin battery or supercapacitor. This video, courtesy of Stanford University, shows that process, and includes Dr. Cui lighting an LED with a small square of paper. He and his …