New discovery makes fast-charging, better performing lithium-ion batteries possible

April –  2019 – Rensselaer Polytechnic Institute – Material Science

Creating a lithium-ion battery that can charge in a matter of minutes but still operate at a high capacity is possible, according to research from Rensselaer Polytechnic Institute just published in Nature Communications. This development has the potential to improve battery performance for consumer electronics, solar grid storage, and electric vehicles.

A lithium-ion battery charges and discharges as lithium ions move between two electrodes, called an anode and a cathode. In a traditional lithium-ion battery, the anode is made of graphite, while the cathode is composed of lithium cobalt oxide.

These materials perform well together, which is why lithium-ion batteries have become increasingly popular, but researchers at Rensselaer believe the function can be enhanced further.

“The way to make batteries better is to improve the materials used for the electrodes,” said Nikhil Koratkar, professor of mechanical, aerospace, and nuclear engineering at Rensselaer, and corresponding author of the paper. “What we are trying to do is make lithium-ion technology even better in performance.”

Vanadium disulfide – a promising new monolayer material for Li-ion batteries

Koratkar’s extensive research into nanotechnology and energy storage has placed him among the most highly cited researchers in the world. In this most recent work, Koratkar and his team improved performance by substituting cobalt oxide with vanadium disulfide (VS2).

“It gives you higher energy density, because it’s light. And it gives you faster charging capability, because it’s highly conductive. From those points of view, we were attracted to this material,” said Koratkar, who is also a professor in the Department of Materials Science and Engineering.

Excitement surrounding the potential of VS2 has been growing in recent years, but until now, Koratkar said, researchers had been challenged by its instability–a characteristic that would lead to short battery life. The Rensselaer researchers not only established why that instability was happening, but also developed a way to combat it.

The team, which also included Vincent Meunier, head of the Department of Physics, Applied Physics, and Astronomy, and others, determined that lithium insertion caused an asymmetry in the spacing between vanadium atoms, known as Peierls distortion, which was responsible for the breakup of the VS2 flakes. They discovered that covering the flakes with a nanolayered coating of titanium disulfide (TiS2)–a material that does not Peierls distort–would stabilize the VS2 flakes and improve their performance within the battery.

“This was new. People hadn’t realized this was the underlying cause,” Koratkar said. “The TiS2 coating acts as a buffer layer. It holds the VS2 material together, providing mechanical support.”

Once that problem was solved, the team found that the VS2-TiS2 electrodes could operate at a high specific capacity, or store a lot of charge per unit mass. Koratkar said that vanadium and sulfur’s small size and weight allow them to deliver a high capacity and energy density. Their small size would also contribute to a compact battery.

When charging was done more quickly, Koratkar said, the capacity didn’t dip as significantly as it often does with other electrodes. The electrodes were able to maintain a reasonable capacity because, unlike cobalt oxide, the VS2-TiS2 material is electrically conductive.

Koratkar sees multiple applications for this discovery in improving car batteries, power for portable electronics, and solar energy storage where high capacity is important, but increased charging speed would also be attractive.

Rensselaer Polytechnic Institute

 

Vanadium disulfide flakes with nanolayered titanium disulfide coating as cathode materials in lithium-ion batteries Lu Li, Zhaodong Li, Anthony Yoshimura, Congli Sun, Tianmeng Wang, Yanwen Chen, Zhizhong Chen, Aaron Littlejohn, Yu Xiang, Prateek Hundekar, Stephen F. Bartolucci, Jian Shi, Su-Fei Shi, Vincent Meunier, Gwo-Ching Wang & Nikhil Koratkar Nature Communications volume 10, Article number: 1764 (2019)

Rensselaer Polytechnic Institute

#Batteries #Energy #MaterialScience

Rivian electric pickup truck will be able to steer like a tank — here’s what it looks like

Rivian’s electric pickup truck, the R1T, is going to have some special features, and one less known about is the ability to steer like a tank.

 

After the unveiling event last year, we took a close look at Rivian’s R1T all-electric pickup truck, and I was so impressed that I ordered one.

It’s equipped with four electric motors, each a 147 kW power capacity at the wheel, while the total power output can be configured to different levels, from 300 kW to 562 kW (input to gearbox).

The system gives Rivian an incredible ability to control to torque at the wheel, which the company can use to steer the pickup truck almost like a tank.

Auto Vision produced a CGI video showing what this tank steering could look like on the Rivian R1T:

While this video is CGI, we have seen an actual video, which Rivian has yet to release, of a prototype of the R1T doing exactly that, and even more impressive tank steering.

As for the other specs, the different power levels (300 kW to 562 kW) match different choices of battery packs, which are another impressive feature since they have the highest capacity of any other passenger electric vehicle out there: 105 kWh, 135 kWh, and 180 kWh.

Rivian says that it will translate to “230+ miles, 300+ miles, and 400+ miles” of range on a full charge.

They’re talking about a charge rate of up to 160 kW at fast-charging stations and an 11-kW onboard charger for level 2 charging.

The automaker is trying to bring the truck to market by the end of next year with a starting price of $69,000.

Electrek’s Take

This CGI video is an interesting example, but I have to say that the actual video we saw of the prototype was way more impressive.

It actually showed the electric truck basically doing multiple 360-degree turns in place.

At the time, we were told that Rivian was working on a way to only allow owners to make that happen off-road on softer surfaces than asphalt in order to avoid destroying the tires.

It could be a useful and fun feature for off-road driving, and Rivian has been really showing the capability of using its electric pickup truck off-road, including with a cool camper mode of the Rivian R1T pickup.

I really can’t wait to test that truck.

Update: All-Electric Car Range, Price & More Compared For U.S. – July 2019

The BEV offer in the U.S. is getting more attractive on both ends – affordable and high-end. 

The third quarter of this year brings us several changes in pricing and availability of all-electric cars in the U.S.– those changes are mostly related to Tesla models.

First of all, from July on, Tesla buyers can count on only $1,875 of federal tax credit (instead of $3,750). Secondly, Tesla lowered prices of 3/S/X and dropped some versions entirely. Other than that, we didn’t note any important changes, but as always in the car business – the real prices can be much lower than MSRP (like the Chevrolet Bolt EV, for example) or much higher than MSRP (when a particular model is production constrained).

Below we attached a comparison in the form of a table as well as charts, sorted by range and by price. Each position is a separate model (or version if there are differences in range or powertrain).

All-Electric Cars Compared By Range, U.S. – July 22, 2019

The range of BEVs varies from less than 60 miles to 370 miles (595 km), according to the EPA. Six Tesla versions are above 300 miles, in total 16 BEVs are above 200 miles.

All-Electric Cars Compared By Price, U.S. – July 22, 2019

Taking into consideration MSRP and deducting the federal tax credit, the base 200+ mile range electric cars start at around $30,000.

As many Chevrolet dealers often lower the Bolt EV price by several thousand, you could get a 200+ mile BEV for less than $30,000.

** Some models estimated.

Article re-posted from InsideEvs.

Successful Entrepreneurs and Chinese Bamboo Trees have a Lot in Common

Most entrepreneurs will tell you that it’s perfectly reasonable to quit after five years of not seeing results. In fact, I don’t think many business owners would last five years. I’ll be the first to admit that I would just give up after no results around year three or four.

 

Now, here’s an interesting story a coach of mine told me a while ago that has a great lesson for entrepreneurs. It’s the story of the Chinese Bamboo Tree.

To grow the Chinese Bamboo Tree, you’d water it, make sure that it gets enough sunshine — all the usual stuff. But even if you do everything right, you won’t see any visible signs of growth in the first year. Nor the second, third, or fourth year.

 

But in the fifth year, something magical happens! Your plant, which has been dormant all this time, suddenly shoots up by 80 feet in just six weeks, and it becomes virtually unrecognizable over that short span of time.

The Chinese Bamboo Tree story is pretty amazing in its own right, and it gets even cooler when you realize that this mirrors the situation that entrepreneurs face in real life. Here are three takeaways from the story that you can apply to your business to help it grow:

1. Work on your foundation.

If you’re working on a new business, the first thing that you should do is work on your foundation. Create processes and systems to streamline your workflow. Hire the right people. Train them, and teach them to solve problems.

Once you’ve put together a strong foundation for your company, it’ll start growing really fast — just like the Chinese Bamboo Tree. Just remember to be patient while you build on that foundation, and don’t fall into the trap of cutting corners.

As entrepreneurs, we all talk about scaling our companies and gaining traction, but keep in mind that this doesn’t happen overnight. Even if you pump in $50,000 into Facebook ads or Google ads, and get a ton of orders, it’ll be hard for you to fulfill those orders effectively and keep your customers happy if you don’t have a solid foundation to start off with.

2. Reinvest your money in your business.

Once you start making money, reinvest the money into your business so that you can keep growing and building upon that foundation.

 

 

More specifically, spend on customer service so that you can provide a better experience, spend on new technology so you can automate certain processes and boost productivity, and spend on coaching so you can identify your weaknesses and improve upon them.

 

Read More: 6 Success Lessons You Should Learn from a Bamboo Tree

Personally, I hired a coach to help me take my business to the next level, and after implementing his suggestions (creating operational manuals, organizational charts, etc), I’ve definitely noticed an increase in my team’s effectiveness.

3. Stop chasing shiny objects.

Finally, stop getting distracted by every new tactic, strategy, or marketing channel that you hear about. At the end of the day, you don’t want to spread yourself too thin — this will hurt your focus, and make it hard for you to achieve your business goals.

 

Think about it: say you’re taking care of your Chinese Bamboo Tree, and after seeing that it’s not growing, you try giving it a different brand of fertilizer every week. I’m no expert on gardening, but even I can tell you that you’ll kill the plant by the end of the month.

 

Posted from Inc. Business Forum: T. Mello

Graphene Container System for Manufacturing

A graphene container system for manufacturing has been developed by GrapheneCA. The 40-foot containers are designed specifically for industrial producers and high-tech applications of graphene.

“It has developed a novel Mobile Graphene Container System (MGCS), the world’s first scalable, modular graphene production system, to help companies manufacture graphene in-house.
 
The New York-based company, which develops graphene-based technology for industries, said MGCS is available in 40-foot containers that are designed specifically for industrial producers and high-tech applications. The company said that with MGCS’ high quality, “ecologically clean graphene can be produced in-house” anywhere in the world.
 
“Think of Mobile Graphene Container System as your own graphene production line,” said David Robles, head of business development at GrapheneCA. “Producers will be able to secure a constant graphene supply and have greater control over their production volume and price.”
 
Robles said the process eliminates the reliance on “third-party suppliers and complicated logistics.”The industrial containers produce a high volume of industrial graphene in quantities of 4 tons of powder or more than 12 tons of graphene paste, said the company.
 
For high-tech applications, MGCS is able to produce pure graphene and graphene oxides derivatives, a much finer quality of product. The manufactured products have additional drying and quality-control features that reduce the need for graphene experts.
 
The company said that the next generation method simplifies graphene production and addresses problems that crop up during product shipments.
 
Graphene shipping is filled with complications due to the material being a highly voluminous compound, greatly limiting the amount of product that can be stored in a shipping container. MGCS allows for a clever work-around whereby ecologically clean graphene can be produced in-house by a company eliminating high shipping costs. Production only needs a water source and electric, diesel or bio-diesel power.”

 
Read full article GrapheneCA creates mobile graphene container system for in-house graphene manufacturing

The Nano–Bio Interactions of Nanomedicines: ENMs – Understanding the Biochemical Driving Forces and Redox Reactions

Engineered nanomaterials (ENMs) have been developed for imaging, drug delivery, diagnosis, and clinical therapeutic purposes because of their outstanding physicochemical characteristics.

However, the function and ultimate efficiency of nanomedicines remain unsatisfactory for clinical application, mainly because of our insufficient understanding of nanomaterial/nanomedicine–biology (nano–bio) interactions.

The nonequilibrated, complex, and heterogeneous nature of the biological milieu inevitably influences the dynamic bioidentity of nanoformulations at each site (i.e., the interfaces at different biological fluids (biofluids), environments, or biological structures) of nano–bio interactions.

The continuous interplay between a nanomedicine and the biological molecules and structures in the biological environments can, for example, affect cellular uptake or completely alter the designed function of the nanomedicine.

Accordingly, the weak and strong driving forces at the nano–bio interface may elicit structural reconformation, decrease bioactivity, and induce dysfunction of the nanomaterial and/or redox reactions with biological molecules, all of which may elicit unintended and unexpected biological outcomes.

In contrast, these driving forces also can be manipulated to mitigate the toxicity of ENMs or improve the targeting abilities of ENMs.

Therefore, a comprehensive understanding of the underlying mechanisms of nano–bio interactions is paramount for the intelligent design of safe and effective nanomedicines.

In this Account, we summarize our recent progress in probing the nano–bio interaction of nanomedicines, focusing on the driving force and redox reaction at the nano–bio interface, which have been recognized as the main factors that regulate the functions and toxicities of nanomedicines.

First, we provide insight into the driving force that shapes the boundary of different nano–bio interfaces (including proteins, cell membranes, and biofluids), for instance, hydrophobic, electrostatic, hydrogen bond, molecular recognition, metal-coordinate, and stereoselective interactions that influence the different nano–bio interactions at each contact site in the biological environment.

The physicochemical properties of both the nanoparticle and the biomolecule are varied, causing structure recombination, dysfunction, and bioactivity loss of proteins; correspondingly, the surface properties, biological functions, intracellular uptake pathways, and fate of ENMs are also influenced.

Second, with the help of these driving forces, four kinds of redox interactions with reactive oxygen species (ROS), antioxidant, sorbate, and the prosthetic group of oxidoreductases are utilized to regulate the intracellular redox equilibrium and construct synergetic nanomedicines for combating bacteria and cancers. Three kinds of electron-transfer mechanisms are involved in designing nanomedicines, including direct electron injection, sorbate-mediated, and irradiation-induced processes.

Finally, we discuss the factors that influence the nano–bio interactions and propose corresponding strategies to manipulate the nano–bio interactions for advancing nanomedicine design. We expect our efforts in understanding the nano–bio interaction and the future development of this field will bring nanomedicine to human use more quickly.

New stable, transparent, and flexible electronic device that emulates essential synaptic behaviors, with potential for #AI in organic environments.

Structure and materials of the transparent and flexible synapses. a) Illustration of the identical bio-synapse and artificial synapse structures.

Waterproof artificial synapses for pattern recognition in organic environments

The two electrodes and the functional layer correspond to pre-synapse, post-synapse, and synaptic cleft, respectively. b) Schematic of the ITO/PEDOT:PSS/ITO flexible and transparent artificial synaptic device. c) Top and d) cross- sectional SEM images of the PEDOT:PSS film on the Si substrate. The film thickness was 42.18 nm. e) Schematic structure and f) Raman spectra of PEDOT:PSS. g) Transmittance spectrum of the PET/ITO, PET/ITO/PEDOT:PSS, and PET/ITO/PEDOT:PSS/ITO structures. h) AFM image (2×2 μm2) of the PEDOT:PSS film on the PET/ITO substrate. Root-mean-square average roughness (Rq) was 1.99 nm. Credit: Wang et al.

Most artificial intelligence (AI) systems try to replicate biological mechanisms and behaviors observed in nature. One key example of this is electronic synapses (e-synapses), which try to reproduce junctions between nerve cells that enable the transmission of electrical or chemical signals to target cells in the human body, known as synapses.

Over the past few years, researchers have simulated versatile synapticfunctions using single physical devices. These devices could soon enable advanced learning and memory capabilities in machines, emulating functions of the human brain. 

Recent studies have proposed flexible, transparent and even bio-compatible electronic devices for pattern recognition, which could pave the way toward a new generation of wearable and implantable synaptic systems. These “invisible” e-synapses, however, come with a notable disadvantage: they easily dissolve in water or in organic solutions, which is far from ideal for wearable applications. 

To overcome this limitation, researchers at Fudan University in Shangai have set out to develop a new stable, flexible and waterproof synapse suitable for applications in organic environments. Their study, outlined in a paper published in the Royal Society of Chemistry’s Nanoscale Horizons journal, presents a new fully transparent electronic device that emulates essential synaptic behaviors, such as paired-pulse facilitation (PPF), long-term potentiation/depression (LTP/LTD) and learning-forgetting-relearning processes. 

“In the present work, a stable waterproof artificial synapse based on a fully transparent electronic device, suitable for wearable applications in an organic environment, is for the first time demonstrated,” the researchers wrote in their paper.

The flexible, fully transparent and waterproof device developed by the researchers has so far achieved remarkable results, with an optical transmittance of ~87.5 percent in the visible light range. It was also able to reliable replicate LTP/LTD processes under bended states. LTP/LTD are two processes affecting synaptic plasticity, which respectively entail an enhancement and decrease in synaptic strength. 

The researchers tested their synapses by immersing them in water and in five common organic solvents for over 12 hours. They found that they functioned with 6000 spikes without noticeable degradation. The researchers also used their e-synapses to develop a device-to-system-level simulation framework, which achieved a handwritten digit recognition accuracy of 92.4 percent. 

“The device demonstrated an excellent transparency of 87.5 percent at 550nm wavelength and flexibility at a radius of 5mm,” the researchers wrote in their paper. “Typical synaptic plasticity characteristics, including EPSC/IPSC, PPF and learning-forgetting-relearning processes, were emulated. Furthermore, the e-synapse exhibited reliable LTP/LTD behaviors at flat and bended states, even after being immersed in water and organic solvents for over 12 hours.” 

The device proposed by this team of researchers is the first “invisible” and waterproof e-synapse that can reliably operate in organic environments without any damage or deterioration. In the future, it could aid the development of new reliable brain-inspired neuromorphic systems, including wearable and implantable devices.

More information: Tian-Yu Wang et al. Fully transparent, flexible and waterproof synapses with pattern recognition in organic environments, Nanoscale Horizons (2019). DOI: 10.1039/C9NH00341J

© 2019 Science X Network