Even with Batteries, Paul MacCready Was Right

Dean Sigler Batteries, Sustainable Aviation 0 Comments

Dr. Paul MacCready repeatedly urged us to do more with less, getting big results from modest use of materials.  That philosophy may be upheld yet once again by researchers from the Helmholtz-Zentrum Berlin (HZB) Institute of Soft Matter and Functional Materials. As reported here many times, people like Dr. Yi Cui at Stanford University, researchers at MIT, the Fraunhoffer Institute in Germany and many others are attempting to find the magic combination of ingredients that will allow us to transcend the weight penalty we currently trade for payload in heavier-than-desired electric aircraft. Scientists at the HZB, led by  by Prof. Matthias Ballauff have directly observed for the first time a lithium-silicon half-cell during its charging and discharge cycles.  Dr. Beatrix-Kamelia …

Caging Silicon Anodes with Graphene

Dean Sigler Announcements, Batteries, Sustainable Aviation 0 Comments

Dr. Yi Cui of Stanford University has expanded the idea of “battery” to include conductive ink on paper, fruit-like clusters of energy-storing capsules, and now, nano-sized graphene cages in which the energy can romp like a hamster in a plastic ball.  He will be on hand at this year’s Sustainable Aviation Symposium on May 6, at the Sofitel San Francisco Bay hotel. His pioneering work with silicon as an electrode material goes back at least ten years, and has focused on overcoming silicon’s two major problems in battery use.  Silicon expands and begins breaking down during repeated charge-discharge cycles.  It reacts with battery electrolyte to form a coating that progressively destroys performance.  The combination of crumbling and coating finally makes the …

Potassium Graphite Batteries?

Dean Sigler Electric Aircraft Materials, Electric Powerplants, Sustainable Aviation 0 Comments

The greatest obstacle to discovery is not ignorance – it is the illusion of knowledge. Daniel J. Boorstin Oregon State University researchers in Corvallis, Oregon have worked around an intellectual roadblock they say has kept potassium from serious consideration as a battery material for over eight decades.  This could be good news, since potassium is more plentiful and lower cost than lithium, and according to OSU scientists, almost as energetic. Xiulei (David) Ji, the lead author of the study and an assistant professor of chemistry in the College of Science at Oregon State University. points out that potassium-ion batteries haven’t been considered since the Hoover administration. Ji said, “For decades, people have assumed that potassium couldn’t work with graphite or …

EAS IX:  Materials Design for Battery Breakthroughs

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Dr. Yi Cui’s presentation title ended with, “from Fundamental Science to Commercialization,” an indication of the long, tough road that new developments are forced to take.  Considering that Sony introduced the Lithium battery as a commercial entity in 1991 (and that following at least an 18-year slog from laboratory to mass production), mostly incremental changes have come for the chemistry, echoing Dr. Cui’s pronouncement at EAS III that lithium batteries followed a “growth curve” of about eight percent per year, meaning that about every nine years, they should double in performance. Cui’s estimate has been borne out in reality, Nature magazine reporting in 2014, “Modern Li-ion batteries hold more than twice as much energy by weight as the first commercial …

Aluminum Yolks and Titanium Shells

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A new “yolk-and-shell” nanoparticle could boost the capacity and power of lithium-ion batteries. MIT’s press release gives a graphic overview of what damages electrodes and shortens battery life.  “One big problem faced by electrodes in rechargeable batteries, as they go through repeated cycles of charging and discharging, is that they must expand and shrink during each cycle — sometimes doubling in volume, and then shrinking back. This can lead to repeated shedding and reformation of its “skin” layer that consumes lithium irreversibly, degrading the battery’s performance over time.” Dr. Yi Cui and teams at  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 a similar  joint …

Samsung Almost Doubles Li-Ion Battery Capacity – in the Near Future

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

Several sources report on Samsung’s announcement that they have developed a new technology that enables them to coat silicon battery cathodes with high crystal graphene, virtually doubling the capacity of lithium-ion batteries. Of course, Samsung relates this immediately to their popular smartphones and tablets, but the significance of this is not lost on electric vehicle designers.  Doubling the range of EVs “without adding a single pound of weight” would be a true game changer.  But don’t get excited too quickly. Silicon electrodes have been a major research effort for people like Dr. Yi Cui, who spoke at this year’s Electric Aircraft Symposium.  Issue surrounding their successful use have included silicon’s expansion when being charged and contraction when being discharged.  This …

Dr. Yi Cui’s Latest, a Solid-state Electrolyte

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Green Car Congress reports that, “Stanford researchers led by Professor Yi Cui have used ceramic nanowire fillers to enhance the ionic conductivity of polymer-based solid electrolyte by three orders of magnitude. The ceramic-nanowire filled composite polymer electrolyte also shows an enlarged electrochemical stability window.” With solid-state batteries coming to the fore through efforts by Ann Marie Sastry at Sakti 3 and Qichao Hu at Solid Energy Systems, an improved solid electrolyte would seem to offer greater battery safety and stability “when compared with conventional liquid electrolytes. The abstract for the Stanford researchers’ paper in the journal ACS Nano Letters explains that “Currently, the low mobility of lithium ions in solid electrolytes limits their practical application. The ongoing research over the past few …

Flow Batteries at Stanford and in Lichtenstein

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

Dr. Yi Cui is a Stanford University associate professor of materials science and engineering and a member of the Stanford Institute for Materials and Energy Sciences, a joint institute with SLAC, the National Acceleration Laboratory.  He has spoken at three Electric Aircraft Symposiums, and has worked for at least the last decade on various technologies and tactics to bring battery science to a high level. His latest effort involves “a low-cost, long-life battery that could enable solar and wind energy to become major suppliers to the electrical grid,” according to a press release from SLAC.  Dr. Cui says, “We believe our new battery may be the best yet designed to regulate the natural fluctuations of these alternative energies.” Of concern …

Dr. Cui’s Pomegranate-inspired Battery Bears Fruit

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Dr. Yi Cui seems to get inspiration from food.  A few years ago, his research team came up with a “yolk-shell structure” that helped contain the high amount of lithium that silicon anodes were able to absorb.  That battery design promised much, and an embellishment of that design seems to hold even greater promise. His newest effort, working at Stanford University with the Department of Energy’s SLAC National Accelerator Laboratory, features an electrode “designed like a pomegranate – with silicon nanoparticles clustered like seed in a tough carbon rind.”  This approach, according to its inventors, overcomes several remaining obstacles to the use of silicon in a new generation of lithium-ion batteries. Yi said the battery’s efficiency and longevity are promising.  …

Free Battery Software May Free Battery Designers

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

Your editor used to teach a class on technical writing.   One of its premises was that good technical writing should be so clear it helps us see the error of our ways.  If the knights in Monty Python and the Holy Grail had done a brief description and a few simple drawings before catapulting cows over their enemy’s walls, they might have realized that they had supplied bovine bombs for the enemy to catapult back. To avoid similar defeats on the stored energy front, engineers at Washington University in St. Louis have cooked up a Cliff’s Notes of how different battery chemistries will behave when being charged.  This “back of the envelope calculation,” as Venkat Subramanian, PhD, associate professor of …