Transportation | Automotive Electronics

A team of researchers from the US and China have developed novel polymer−graphene nanocomposites as high-rate cathode materials for rechargeable lithium batteries. Compared to the pure polymer, the polymer-graphene nanocomposites possess much higher active material utilization ratios and superior ultrafast-charge and -discharge ability; one of the materials maintained a discharge capacity of 100 mAh/g even at 100 C, when the whole discharge process takes only 16 seconds.

The team, including researchers from Penn State University, the University of New Mexico, SUNY Binghamton, General Motors Technical Center, Wuhan University (China), and Pacific Northwest National Laboratory, combined graphene with two promising polymer cathode materials, poly(anthraquinonyl sulfide) (PAQS) and polyimide (PI), to improve their high-rate performance. A paper on their work appears in the ACS journal Nano Letters.

Besides the conventional inorganic materials [for Li-ion battery cathodes], organic cathode materials, including small molecules and polymers, have also been emphasized recently as a new generation of “green” lithium battery electrodes due to their sustainability and environmental benignancy. The electrochemical redox mechanism of an organic cathode is based on the reversible redox reaction of the organic functional group, such as quinone, anhydride, and nitroxide radical, accompanied by the association and disassociation of Li+ ions or electrolyte anions.

...A polymer with a stable skeleton and highly electroactive functional group can potentially be a high-power cathode candidate because its redox reaction intrinsically has faster kinetics than inorganic intercalation cathodes. For example, anthraquinone can show electrochemical redox activity at a fast scan rate of 1000 mV/s in cyclic voltammetry tests in acetonitrile, and nitroxide radical polymer can still retain 97% of its theoretical capacity even at a charge rate of 1200 C and discharge rate of 60 C in aqueous electrolyte. Moreover, the robust backbone of the polymer can prevent the unwanted dissolution in nonaqueous electrolyte that is always suffered by small molecules, and thereby achieve good cycling stability.

—Song et al.

The researchers had earlier reported some polymers showing high capacity, high Coulombic efficiency, and good cycling stability, but the high-rate performance was unsatisfactory. While other work has shown the ability of graphene to function as a conductive additive, active material loading in the electrode composite was only 10%, while the graphene loading was as high as 60%.

In this new study, Song et al. demonstrated a general one-pot synthesis of polymer−graphene nanocomposites with highly dispersed graphene. They synthesized the polymer–graphene nanocomposites through a simple in situ polymerization in the presence of graphene sheets; the highly dispersed graphene sheets in the nanocomposite drastically enhanced the electronic conductivity and allowed the electrochemical activity of the polymer cathode to be efficiently utilized, allowing for ultrafast charging and discharging.

Their cathodes contained 60 wt % active material (polymer or polymer−graphene composite), 30 wt % conductive carbon, and 10 wt % polytetrafluoroethylene (PTFE) binder. They characterized their polymer−graphene nanocomposites by galvanostatic charge−discharge tests of CR2016-type coin cells.

They found that the discharge capacity of PAQS, after the initial several activation cycles, stabilizes at 177 mAh/g and a utilization ratio of 79% can be achieved relative to the theoretical capacity of 225 mAh/g. One of the PAQS materials maintained a discharge capacity of 100 mAh/g at 100 C. The capacity of PI-graphene materials was 172 and 205 mAh/g, corresponding to a polymer utilization ratio of 49 and 62%, respectively.

On the basis of the above electrochemical performance, we conclude that formation of graphene-based nanocomposites can significantly improve not only the specific capacity, but also the rate capability of polymer cathode materials, especially at ultrahigh current rates.

...The outstanding high-rate performance is explained by the fast redox kinetics, the fast electron transfer, and the benefits to Li− ion conduction due to increased surface area in the polymer− graphene nanocomposites. Since the battery performance of these kinds of polymer−graphene nanocomposites is so attractive and the synthesis is very simple, it gives important insights into improving battery performance of other polymer cathodes.

—Song et al.

This work was primarily supported by Penn State startup fund and the US Department of Energy (DOE) under the Batteries for Advanced Transportation Technologies (BATT) Program.

Source: GreenCarCongress

Taking the principal that to see through something you need to see what's behind it, they covered the driver's side of the car in mats of LEDs, and mounted a digital SLR camera on the opposite side of the vehicle.

The camera shoots video on the passenger side of the car and the video is displayed in real time on the driver side of the automobile.

This ingenious approach, originally pioneered by scientists at the University of Tokyo, works on the same principles of the blue screen used by TV weather forecasters and Hollywood filmmakers.

The idea also mimics the iPad 2 Halloween costume that seems to displays a gaping hole in the human body.

The next conundrum-what to do with an invisible car ? Take it on a week long tour of Germany, obviously.

In Mercedes' promotional video, stupefied Muggles stare and fall about in shock as the team put the car through its paces along the highways of Hamburg and the bridges of Bavaria.

Meanwhile online. while some pessimistic YouTube users were wary, anticipating that invisible cars would no doubt lead to brutal crashes, others fantasised about bring able to park anywhere at all, without getting a ticket.

See full article here.

By Stephan Lehmann — Many in the automotive industry believe that the automobile will undergo more changes in the next 15 years than it has since its inception 125 year ago. Through partnerships, this industry is working towards fuel efficiency and a world without accidents. Vehicles will connect to each other and to the cloud creating opportunities beyond imagination.

In this video, Tim Nixon, Karla Wallace and Mike Grimes from GM, as well as John Schneider from Ford, share incredible energy, excitement and passion for the progress being made in the automotive industry and the future evolution of the connected car.

Mike Grimes summarizes it nicely: “I thought I would have retired with technology that actually has already occurred. So, I’m already beyond my retirement point and now I’m just having fun!”

Read more about it

(via AP Photo/Paul Sancya)

Two of my favorite car companies have partnered together, Ford and Toyota, to work on my favorite drive topology, rear-wheel drive, with everyone's favorite engine system, the hybrid.

● The partnership sets the two companies on equal footing in an effort to create and advanced hybrid system for rear-wheel drive light trucks and SUVs.

● The goal is to deliver greater fuel efficiency while not compromising the performance of the vehicles.

● The team will also work towards developing the next-generation standards for in vehicle internet and digital communication systems.

● Ford and Toyota pledge to deliver the new tech within the coming decade.

I like where their minds are at. However, I would like to see this same hybrid RWD system come to consumer and sport cars. I believe I am not the only one. Perhaps market demand with usher in a new revival for RWD. We can only hope.

Cabe

Why  does every electric car that boasts a world record range on a single  charge always looks like it is from an ugly Buck Rogers future?

Buck Rogers Rocket Ship (left)  Bluebird EV capable of 500 mph (Right)

Schluckspecht E (left) and with the Schluckspecht Team (right)  (via Team Schluckspecht)

Team  Schluckspecht just barely does away with the outer-space fairing look  with their new world record holding electric vehicle (EV), the  "Schluckspecht E" or "Boozer E" in English. On a single charge the EV  travelled 1,013.8 miles (1,631.5 km) over a span of 36 hours and 12  minutes. The efficiency comes from taking as much mass out of the EV's  chassis, only having one seat, and evenly dividing the power demand  equally between 14 individual lithium-cobalt batteries. Drive in applied  directly via two motors, one on each front wheel, which does away with a  transmission. However, the team did not break any land-speed records.  The Boozer could only reach 28 mph (45 km/h). The test took place at the Bosch corporate race track in Boxberg, Germany.

I  would stomach driving this EV if it could go 65 mph. I am sure much of  the range will be lost adding a transmission, but it would still best  every EV available today.

Eavesdropper