Lithium News

Ahead of launching its first electric vehicle, Porsche wants to flesh out a plan for charging infrastructure.

In a new interview released by the company, two Porsche executives explain the automaker’s approach to charging electric cars: seamless and fast.

Otmar Bitsche, Director of Development Electrics, Electronics, Electromobility at Porsche and Michael Kiefer, Director of High-Voltage Systems at Porsche Engineering, describe how they are approaching the issue of charging both on the technology aspect and as a service.

From a technology standpoint, they are introducing the first system working at 800-volts, which is going to enable a charge rate of up to 350 kW.

Kiefer explained:

“Our power range starts at about 150 kilowatts today and extends up to 350 kilowatts. In a later phase of development, it could be even more than that. We believe that everything that will be installed in the future will play out in this power range. In the public space, no one wants to have long-term parkers at the charging stations because charging takes so long. Low charging capacity is really only acceptable for charging at home.”

Of course, that high charge rate is only going to be achievable when the state-of-charge of the battery pack is relatively low.

As the battery becomes full, they need to reduce the charge rate to protect the pack.

Bitsche explained:

“It’s not possible to get a 100 % charge with fast charging. As the charge level rises, the power has to be cut back. Altogether, we can charge for 400 kilometers in as little as 20 minutes without the battery suffering. That makes the charging experience very pleasant for the driver, because the vehicle controls the charging completely automatically.”

In terms of technology, Porsche is also deploying two different systems to enable fast-charging for different types of charging stations.

Kiefer continued:

“We have two different variants, the charging park and the ChargeBox. The park is designed for locations with more available space in which a very high volume of charges is to be expected, 24 hours a day, seven days a week. With a small compact station, however, a charging park is possible in the city as well, for example in a residential area. For all areas with extreme space constraints, there is our second variant, the ChargeBox with an integrate battery. It can be connected to the normal low-voltage grid and enables fast charging in spite of its compact dimensions.”

We reported on Porsche installing its first ultra-fast 350 kW EV charging station and connecting it to the grid earlier this year.

As for the service aspect, Porsche wants a seamless experience that doesn’t require their owners to deal with multiple services.

Kiefer explained:

“Someone who wants to drive from Munich to Hamburg in an electric vehicle today needs multiple cards with which they have to authenticate themselves at the charging stations. Porsche eliminates this authentication rigmarole for customers by establishing contracts with all of the charging station operators, so the customer only needs one charging card that is accepted everywhere. And they can also count on a guaranteed electricity price that applies throughout the entire country. Customers of the Porsche charging service ultimately receive just one transparent bill from Porsche.”

His example is not entirely accurate since Tesla’s Supercharger network has an extensive number of stations between Munich to Hamburg that its drivers can use seamlessly without using a card or authentication.

That said, it is true for virtually any other electric vehicle.

Porsche is addressing this by launching its own electric car charging mobile app and service to facilitate the charging experience.

The two engineering executives also said that inductive charging is also being evaluated by the company and could be added to the Taycan later on.

The automaker plans to launch the Taycan, its first all-electric vehicle, next year.

In January 2017 the world’s lightest mechanical chronograph watch was unveiled in Geneva, Switzerland, showcasing innovative composite development by using graphene. Now the research behind the project has been published. The unique precision-engineered watch was a result of collaboration between the University of Manchester, Richard Mille Watches and McLaren Applied Technologies.

The RM 50-03 watch was made using a unique composite incorporating graphene to manufacture a strong but lightweight new case to house the watch mechanism, which weighed just 40 grams in total, including the strap.

The collaboration was an exercise in engineering excellence, exploring the methods of correctly aligning graphene within a composite to make the most of the two-dimensional materials superlative properties of mechanical stiffness and strength whilst negating the need for the addition of other, weightier materials.

Now, the research behind this unique watch has been published in the journal Composites Part A: Applied Science and Manufacturing. The work was primarily carried out by a group of researchers at The University of Manchester’s National Graphene Institute.

Project leader Professor Robert Young said, “In this work, through the addition of only a small amount of graphene into the matrix, the mechanical properties of a unidirectionally reinforced carbon fibre composite have been significantly enhanced.

“This could have future impact on precision-engineering industries where strength, stiffness and product weight are key concerns such in as aerospace and automotive.”

The small amount of graphene used was added to a carbon fibre composite with the goal of improving stiffness and reducing weight by requiring the use of less overall material. Since graphene has high levels of stiffness and strength, its use as a reinforcement in polymer composites shows huge potential of further enhancing the mechanical properties of composites.

The final results were achieved with only a 2 percent weight fraction of graphene added to the epoxy resin. The resulting composite with graphene and carbon fibre was then analysed by tensile testing and the mechanisms were revealed primarily by using Raman spectroscopy and X-ray CT scans.

The benefits of this research demonstrate a simple method which can be incorporated into existing industrial processes, allowing for engineering industries to benefit from graphene mechanical properties, such as the manufacture of airplane wings or the body work of high-performance cars.

The research group discovered that when comparing with a carbon fibre equivalent specimen, the addition of graphene significantly improved the tensile stiffness and strength. This occurred when the graphene was dispersed through the material and aligned in in the fibre direction.

Dr. Zheling Li, a University of Manchester research associate, said, “This study presents a way of increasing the axial stiffness and strength of composites by simple conventional processing methods, and clarifying the mechanisms that lead to this reinforcement.”

Aurèle Vuilleumier, R&D manager at Richard Mille, said, “This project is a perfect example of technology transfer from the university to the product. The partnership with McLaren Applied Technologies allows a broad diffusion of graphene-enhanced composites in the industry. As a tangible result, a world record light and strong watch was available for our customers: the RM 50-03.”

Dr. Broderick Coburn, senior mechanical design engineer at McLaren Applied Technologies, said, “The potential of graphene to enhance composites’ structural properties has been known and demonstrated at a lab-scale for some time now. This application, although niche, is a great example of those structural benefits making it through to a prepreg material, and then into an actual product.”

The continuing development of lithium ion batteries has resulted in a series of improvements in electrochemical materials. With goals of reduced price, higher specific energy, and improved safety, the electrolyte has come under close scrutiny as an area where improvements can be made. New solvents, new salts, and new additives are providing electrolyte formulations that can help improve battery performance.

Sam Jaffe, the managing director of Cairn ERA, follows the development of lithium ion electrolytes. His company provides market forecasts and strategic information to battery manufacturers and end users. Jaffe will be a speaker at The Battery Show in Novi, Michigan with a talk titled, “Electrolyte: Technology and Marketing Trends,” which takes place on September 11. Sam spoke with Design News about where the electrolyte market is today and what we can expect in the future.

Organic Solvents

Electrolytes for commercial lithium ion batteries are made up of a mixture of organic solvents and lithium fluoride salts. The purpose of the electrolyte is to allow the mobility of lithium ions between the positive and negative electrodes during charging and discharging. “We will continue to use organic solvents for quite a while. Today, there are no real alternatives,” said Jaffe.

Despite significant improvement in the anode (negative electrode) and cathode (positive electrode) in the past ten years, the electrolytes haven’t changed very much. “Only recently have we seen measurable steps

oward investing heavily in electrolyte research,” said Jaffe. “The components have been pretty steady over the last ten years: LiPF6 combined with a cyclic carbonate, a liner carbonate, and a few traditional additives. The additive space has gotten much more sophisticated in the last few years, where every battery manufacturer and electrolyte company has their ‘secret sauce’ for additives,” he added. Jaffe told us that there used to be two or three additives in an electrolyte, but now there can be as many as ten or fifteen different additives.

What’s New

“People have finally realized that the electrolyte, which used to be thought of as a non-working fluid—a medium through which the ions flowed—is actually an intricate part of making a battery. A lot of effort and time has to be put toward getting the electrolyte right if you are going to introduce anything new into the cathode or anode,” Jaffe said.

“One of the most significant advances of the past few years is high-intensity salt concentrations or ‘solvent in salt.’ They are increasing the ratio of salt to solvent. By mixing with additives, they can dramatically increase the salt amount,” noted Jaffe. The advantages are an acceptance of higher capacity anodes and increased energy capacity because there is more electrochemical active material versus inactive material. “It’s an elaborate three-way balancing act and that’s what makes battery manufacturing hard,” he said.

According to Jaffe, the biggest determining factor in electrolyte cost is the price of the lithium that is used in the salts that are added to the solvents. The price of the solvents have remained fairly constant over the past ten years. The traditional manufacturers from Japan and Korea are recently finding competition from several Chinese manufacturers.

In addition, there are environmental concerns in the manufacturing of electrolytes that come from the use of fluorine. “Any time you use fluorine in an industrial manufacturing process, you end up with environmental concerns,” said Jaffe. This is primarily due to the extreme toxicity of the hydrogen fluoride used to make the LiPF6 salt. Once the salt compound had been synthesized, it is relatively safe to handle.

Growing Production

Jaffe told us the limiting factors for increasing electrolyte production come primarily from the time it takes to bring a plant online to make the materials. “Nobody wants to over-invest in manufacturing capacity, but also, nobody wants to miss the opportunity to be a participant in the battery boom. It’s a five to seven year lead time to build any sort of fluorinated manufacturing process with significant capacity,” he said.

“There is definitely movement in China. Companies have expanded their electrolyte and electrolyte component manufacturing capacities. There’s a lot of activity in the west—both Europe and North America—of companies that have just sat down at the poker table and are being dealt cards, but nobody has laid down their bet yet,” explained Jaffe.

Jaffe has been keeping an eye on solid electrolytes, but doesn’t think that they will be ready for prime time for at least several years. “There will be high-value niche applications within the next five years,” he said, “but they won’t be seen in vehicles for at least five to ten years.”

Addressing major issues limiting the technology’s commercialization, chemists have created a lithium-oxygen battery that lasts longer and packs more energy.

Many technologies, such as electric and autonomous vehicles, drones, smartphones, and electronics in general, are now constrained by large, heavy, and short-lived batteries.

Promised to be lightweight, compact, and almost infinitely rechargeable, lithium-air batteries could theoretically do away with most of the shortcomings of current energy storage technologies, especially lithium-ion batteries.

However, lithium-air batteries themselves, as a concept, suffer from some issues that delay their entrance to the market scene.

Now, researchers at the University of Waterloo (Canada) may have cleared the biggest hurdles getting in the way of Li-air tech.

Long-Lasting Lithium-Oxygen Battery With Near 100% Charge Efficiency

Lithium-air batteries run on ambient air, more specifically the oxygen in the air, to activate the electrochemical reaction that generates power, hence their other name, lithium-oxygen batteries.

The problem is that during the discharge of a lithium-oxygen battery, the oxygen produces compounds (superoxide and lithium peroxide) that react with and corrode the components of the battery.

As these reactive compounds consume the organic electrolyte, which enables the transfer of ions between the electrodes, the li-oxygen battery degrades and eventually loses its recharging abilities.

Recently, however, a team of chemists from the University of Waterloo managed to solve this oxygen-related issue in lithium-oxygen batteries, and “created a working battery with near 100 percent coulombic efficiency.”

Here, researchers made an inorganic oxygen electrolyte from molten salt and, instead of carbon, they used nickel oxide, supported by stainless steel mesh, to make cathodes.

When they ran their battery at 150°C, they found that it generated lithium oxide instead of lithium peroxide that usually damages the battery.

“By storing O2 as lithium oxide (Li2O) instead of lithium peroxide (Li2O2), the battery not only maintained excellent charging characteristics, it achieved the maximum four-electron transfer in the system, thereby increasing the theoretical energy storage by 50 per cent. This work shows that Li-O2 electrochemistry is not intrinsically limited once problems of electrolyte, superoxide, and cathode host are overcome and that coulombic efficiency close to 100% can be achieved.”

The coulombic efficiency describes the ratio of the charge/discharge efficiency in a system, in this case, a battery, between the output and input charges.

“China isn’t building gigafactories,” says Patrick Hurley, chief technology officer of A123, a lithium-ion battery company. “It is building gigacities.”

Gigafactories are named for their capacity to build batteries in tens of gigawatt-hours (GWh) every year, which is about a million times the amount of energy consumed by a typical US household in a day. What Hurley meant by gigacities are complexes that include not just the gigafactory but everything else needed to support it: housing, infrastructure, research and development centers, and universities to train staff.

China’s battery ambition can be seen in the speed at which the country is adding battery-storage capacity. At the start of 2018, China had an operational battery-storage capacity of 389 megawatts (MW). By August, China had added another 340 MW of additional capacity. That’s why the China Energy Storage Alliance (CNESA) declared 2018 to be “one of the most significant years yet for the industry.”

The battery-storage capacity is for storing excess electricity on the grid. Its main use is to smooth out the intermittent production of electricity from sources such as solar and wind—China also leads the world in renewables—or to replace fossil-fuel peaker plants, which are run only during high-demand periods, such as when lots of people turn on air-conditioners when they get home from work on summer evenings.

The battery figures, though impressive, are still tiny when compared to China’s other energy-storage technology: pumped hydro. The country currently has a whopping 30 GW of pumped hydro storage capacity, about 40 times that of battery storage. Pumped hydro works by storing excess electricity in the form of gravitational potential energy. When there is more electricity in the grid than necessary, the excess is used to pump water up a dam. When there’s more demand for energy than currently available otherwise, the water is allowed to fall and run turbines that generate electricity.

Further, neither of these figures include another energy-storage technology: electric-vehicle batteries. In 2017, CNESA estimates that China built 40 GWh worth of batteries for electric cars and buses. That accounts for the batteries in more than 50% of all electric vehicles sold globally in the same year.

(A side note: Watts are used to measure power, or how much electricity can flow per second. Watt-hours are used to measure energy, or the total amount of electricity stored/consumed in one hour. The energy-storage industry tends to use watts when talking about grid-scale storage, because power capacity is as important as energy capacity. On the other hand, electric-vehicle batteries have to be built for high-power applications. So they care to only share figures on storage, which defines how far the car can go on a single charge.)

A new consortium (called the Graphene REACH registration consortium) was launched in 2017 to handle REACH graphene registration in the EU. The consortium members, The Sixth Element Material Technology, NanoXplore and Applied Graphene Materials announced that the joint registration dossiers for graphene and graphene oxide have been submitted to the ECHA.

The consortium is also preparing a JRD for reduced graphene oxide, and hopes to submit it before the end of 2018. The consortium issues a callout for companies (whether graphene producers or importers) to join the consortium or buy a letter of access to the new registrations.

The EU requires all companies that either produce or sell over 1 ton of substances per annumn in the EU to participate in REACH. The current registration limits yearly sells to 10 tons, but the consortium is also aiming to start working on dossier updates for higher volumes (10 to 100 tons per year).

Interestingly the Graphene REACH registration consortia defines the substances as ones with thickness of less than 300 nm, thus covering all substances which are thinner than the substances as defined by the graphite consortia (> 350 nm). The new graphene ISO standard is much more strict – graphene nanoplatelet is defined as typically between 1 to 3 nm thick, while anything larger (and lower than 100 nm) is defined as graphite nanoplateles.