Rumpled Cathodes Benefit Lithium Sulfur Batteries

Dean Sigler Batteries, Sustainable Aviation 0 Comments

We like to think of things inside batteries as neatly organized, but Pennsylvania State University researchers may have come up with a less tidy way of making cathodes. Researchers synthesized “highly crumpled” nitrogen-doped graphene (NG) sheets with “ultrahigh pore volume” and large surface area (1,158 square meters– 12,465 square feet or about one-third the area of a football field) per gram.  This large area and high porosity “enable strong polysulfide adsorption and high sulfur content for use as a cathode material in Li-sulfur batteries.”  Interwoven rather than stacked, the wrinkled material provides ample room for “nitrogen-containing active sites.” The batteries, according to the researchers, “achieved” a high capacity of 1,226 milliamp-hours per gram and 75-percent capacity retention after 300 cycles.  …

Cambridge’s “Ultimate” Battery? Wait 10 Years and See

Dean Sigler Batteries, Electric Aircraft Materials, Electric Powerplants 0 Comments

Cambridge University researchers claim to have successfully demonstrated how several of the problems impeding the practical development of the so-called “ultimate” battery, in this case a lithium-oxygen unit, could be overcome.  They make some pretty impressive claims, saying they’ve developed a working laboratory demonstrator with “very high” energy density – comparable to that of gasoline and with greater than 90-percent efficiency, and the ability to be recharged more than 2,000 times, or 5-1/2 years with a complete cycle and recharge every day. A lithium-oxygen or lithium-air battery of this type would allow an uninterrupted drive between London and Edinburgh on a single charge, about 415 miles, over 100 miles greater than the top mileages promised by Tesla and GM at …

EAS IX: Short Circuiting Batteries on Purpose

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

Recent news from the world of insurance claims adjustors brings us back to ways inspired battery designers might reduce or eliminate certain types of claims, and make electric flight safer. Even when international agreements don’t make progress along those lines. Insurance Claims and international Agreements With recent news of Federal Aviation Administration interest in lithium-ion batteries arising from fires caused by thermal runaways, shipments of large numbers of batteries may be banned.  Claims Journal, an insurance industry news line, quotes Angela Stubblefied, an FAA hazardous materials safety official, as saying, “’We believe the risk is immediate and urgent.’ She cited research showing the batteries can cause explosions and fires capable of destroying a plane. “FAA tests show that even a …

Salting the Battery

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

Ideally, battery materials should be abundant, cheap, and safe.  NaCl (salt) seems to manage three out of three of these, but can it manage the energy and power density of less abundant and more expensive materials such as lithium? Faradion, an English enterprise specializing in “advanced energy storage solutions,” thinks that the salt of the earth may indeed be part of the secret sauce in their new battery.  Initial applications will probably be in large energy-storage systems associated with renewable energy, but forward-looking statements (we used to call them predictions) show the potential for lighter, smaller batteries that could compete with lithium-ion cells. Since the introduction of new technology does not usually come from a single source, Faradion is partnered …

Fast-Charging Batteries with a “Holey” Electrode

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

Replacing the graphite used in conventional battery electrodes with “a network of tin-oxide nanoparticles” could reduce battery charging time from hours to minutes.  An energy storage device combining the advantages of batteries and capacitors is a long-term goal for researchers, and a multi-national discovery may help expedite that goal. Graphite anodes and cathodes, as used in most lithium batteries today, limit storage capacities to 372 milliampere hours per gram (mA·h/g), the theoretical maximum of graphite. By comparison, an Energizer Ultimate Lithium AA battery holds about 3,000 mAh and weighs 14.5 grams (or about 207 mA h/g). A typical rechargeable AA battery holds only 750 to 900 mAh (around 54 to 64 mA h/g).  This limit “hinders significant advances in battery …

Lithium Sulfur Batteries – Energy Storage at New Heights

Dean Sigler Electric Powerplants, Sustainable Aviation 2 Comments

Last year, Oak Ridge National Laboratory (ORNL) announced that researchers had “successfully demonstrated that lithium-sulfur battery technology can indeed outdo lithium-ion on several fronts.”   Theoretically, lithium-sulfur batteries could be four times as energy dense as today’s lithium-ion batteries, but that promise had yet to be demonstrated.  ORNL took initial steps toward that goal, and within the last few months researchers at Vanderbilt University have shown a strong lead in forming lithium-sulfur batteries with commercial potential. Echoing work done at Sakti3, ORNL researchers demonstrated an all-solid-state lithium-sulfur cell, addressing flammability issues shared by batteries with solid electrolytes.  Using lithium polysulfidophosphates (LPSPs) in the cathode, and which have ionic conductivities eight times higher than that of lithium sulfide (Li2S) the team coupled …

The New Mythbusters: Slow Charging May Not Make Batteries Last Longer

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

For the last 60 years, your editor remembers the oft-repeated advice from garage mechanics and now lithium-ion advocates that slow charging is the way to make your batteries last for many cycles.  Where does this put Tesla, for instance, with its 20-minute Superchargers?  Are you damaging your expensive cells by being in a hurry? In yet another example of counter-intuitive thinking at work, researchers at SLAC, the National Accelerator Laboratory at located on the Stanford University campus have challenged several tenets of conventional battery wisdom.  According to PC World, their work, “published on Sunday in the Journal, Nature Materials, challenges the commonly held notion that slowly charging a battery helps prolong its life and that it’s damaging to a battery …

An Electrolyte Gel Sandwich

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

Sekisui Chemical Co., Ltd. makes a wide variety of plastics, films, and active chemical components.  Whipping up something light and powerful in their kitchen must often be a matter of tossing available ingredients into a new recipe.  In this case, they’ve come up with something unique and potentially highly useful. Their research and development center director Satoshi Uenoyama announced “a high-capacity film-type lithium-ion battery “using a coating process that has simultaneously tripled its capacity (compared to other Sekisui Chemical products), increase its safety (as a result of standard safety testing, e.g. no problems with nail penetration tests or crush tests) and speeded up production by ten times (compared to other Sekisui Chemical products).” The company continues comparisons with its products, suggesting lithium-ion conductivity for the …

Getting Batteries in Line

Dean Sigler Uncategorized 0 Comments

In another bid to create the much-hoped-for 10X batteries, researchers at North Carolina State University are rolling their own. As noted in many articles, lithium batteries infused with silicon have a bad habit of swelling and contracting as they charge and discharge, pulverizing the silicon eventually.  Depending on the surrounding materials, the destruction can take place fairly quickly, leading to reduced cycle life for the battery. North Carolina scientists are fighting to extend battery life, though, with what they call “A Novel Nano-architecture for Flexible Lithium Ion Battery Electrodes,” part of the title of their paper in the journal Advanced Materials. Many battery electrodes are some form of graphite composite, and the impetus to wrap these anodes or cathodes in …

A Fix for Dreamliner Battery Woes?

Dean Sigler Electric Powerplants, Sustainable Aviation 1 Comment

With Boeing facing financial doldrums because of its ongoing grounding and resulting slump in sales of the 787 Dreamliner, the stakes are high for the company.  That makes today’s Reuters’ report that the manufacturing giant may have found a “way to fix battery problems on its grounded 787 Dreamliner jets” good news for not only Boeing, but for electric aircraft in general.  Readers should read these findings with some caution, though, since another report from Japan gives a different possible cause for the problems.  That said, the two reports might not be mutually exclusive. Many electric light aircraft developers use spacing between cells and some method to circulate cooling air over them.  In Boeing’s two 787 lithium battery packs, eight …