Category: EV Technology

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Mitsubishi Develops EV Motor Drive with Built-in Silicon Carbide Inverter

Mitsubishi Electric today announced it has developed a prototype electric vehicle (EV) motor drive system with a built-in silicon-carbide inverter. The EV motor drive system, the smallest of its kind, will enable manufacturers to develop EVs offering more passenger space and greater energy efficiency.

Mitsubishi Electric plans to commercialize its new EV motor system after finalizing technologies for motor/inverter cooling, further downsizing and additional efficiency.

Features

1)Downsized motor drive system with integrated all silicon-carbide inverter
-Achieves further system downsizing (14.1L, 60kW) with smaller motor resulting from improved thermal resistance between motor drive system and cooling system.
-Equal to existing EV motors in power and volume, enabling replacement.
2)Improved motor cooling performance
-Integrates cooling system for motor and inverter thanks to cylindrical shape of power module accommodating parallel cooling ducts for motor and inverter.
-Ensures stable cooling with even a low-power pump.

Global demand for EVs and hybrid EVs (HEVs) has been growing in recent years, reflecting increasingly strict regulations for fuel efficiency and growing public interest in saving energy resources and reducing carbon dioxide emissions. As EVs and HEVs require relatively large spaces to accommodate their robust battery systems, there is a strong need to reduce the size and weight of motor systems and other equipment to ensure sufficient passenger space.

Patents
Pending patents for the technology announced in this news release number 94 in Japan and 29 abroad.

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Maxwell & SK to Develop Integrated Lithium Ion Battery-Ultracapacitor

Maxwell Technologies announced today that it has signed a Memorandum of Understanding with SK Innovation, a subsidiary of SK Holdings and Korea's leading energy provider, to develop next generation energy storage solutions leveraging the complementary characteristics of SK's lithium ion batteries and Maxwell's ultracapacitors.

The two companies will explore and identify global commercial opportunities for products that enable enhanced functionality and improve energy efficiency in industrial, transportation and other markets. Lithium ion batteries are characterized by their high energy density, while ultracapacitors offer rapid charge and discharge capabilities, reliable performance in extreme temperature conditions and long operational life.

"As our name implies, we are seeking to move beyond the limitations of existing technologies to develop and deliver products that better meet the requirements of the most demanding energy storage and power delivery applications," said Stephen J. Kim of SK Innovation's battery division. "Our goal is to develop truly differentiated products that will create large new opportunities for both companies."

"While our respective products currently meet the needs of many applications as stand-alone solutions, Maxwell has always believed that ultracapacitors and batteries can be integrated to provide optimized products that offer the best of both worlds in terms of energy and power," said David Schramm, Maxwell's president and chief executive officer. "We are very pleased to have found a major lithium-ion battery producer in SK Innovation that is willing to invest in joint product and market exploration."

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MIT researchers find a way to boost lithium-air battery performance [VIDEO]

Lithium-air batteries have become a hot research area in recent years: They hold the promise of drastically increasing power per battery weight, which could lead, for example, to electric cars with a much greater driving range. But bringing that promise to reality has faced a number of challenges, including the need to develop better, more durable materials for the batteries’ electrodes and improving the number of charging-discharging cycles the batteries can withstand.

Now, MIT researchers have found that adding genetically modified viruses to the production of nanowires — wires that are about the width of a red blood cell, and which can serve as one of a battery’s electrodes — could help solve some of these problems.

The new work is described in a paper published in the journal Nature Communications, co-authored by graduate student Dahyun Oh, professors Angela Belcher and Yang Shao-Horn, and three others. The key to their work was to increase the surface area of the wire, thus increasing the area where electrochemical activity takes place during charging or discharging of the battery.

The researchers produced an array of nanowires, each about 80 nanometers across, using a genetically modified virus called M13, which can capture molecules of metals from water and bind them into structural shapes. In this case, wires of manganese oxide — a “favorite material” for a lithium-air battery’s cathode, Belcher says — were actually made by the viruses. But unlike wires “grown” through conventional chemical methods, these virus-built nanowires have a rough, spiky surface, which dramatically increases their surface area.

Belcher, the W.M. Keck Professor of Energy and a member of MIT’s Koch Institute for Integrative Cancer Research, explains that this process of biosynthesis is “really similar to how an abalone grows its shell” — in that case, by collecting calcium from seawater and depositing it into a solid, linked structure.

The increase in surface area produced by this method can provide “a big advantage,” Belcher says, in lithium-air batteries’ rate of charging and discharging. But the process also has other potential advantages, she says: Unlike conventional fabrication methods, which involve energy-intensive high temperatures and hazardous chemicals, this process can be carried out at room temperature using a water-based process.

Also, rather than isolated wires, the viruses naturally produce a three-dimensional structure of cross-linked wires, which provides greater stability for an electrode.

A final part of the process is the addition of a small amount of a metal, such as palladium, which greatly increases the electrical conductivity of the nanowires and allows them to catalyze reactions that take place during charging and discharging. Other groups have tried to produce such batteries using pure or highly concentrated metals as the electrodes, but this new process drastically lowers how much of the expensive material is needed.

Altogether, these modifications have the potential to produce a battery that could provide two to three times greater energy density — the amount of energy that can be stored for a given weight — than today’s best lithium-ion batteries, a closely related technology that is today's top contender, the researchers say.

Belcher emphasizes that this is early-stage research, and much more work is needed to produce a lithium-air battery that’s viable for commercial production. This work only looked at the production of one component, the cathode; other essential parts, including the electrolyte — the ion conductor that lithium ions traverse from one of the battery’s electrodes to the other — require further research to find reliable, durable materials. Also, while this material was successfully tested through 50 cycles of charging and discharging, for practical use a battery must be capable of withstanding thousands of these cycles.

While these experiments used viruses for the molecular assembly, Belcher says that once the best materials for such batteries are found and tested, actual manufacturing might be done in a different way. This has happened with past materials developed in her lab, she says: The chemistry was initially developed using biological methods, but then alternative means that were more easily scalable for industrial-scale production were substituted in the actual manufacturing.

Jie Xiao, a research scientist at the Pacific Northwest National Laboratory who was not involved in this work, calls it “a great contribution to guide the research on how to effectively manipulate” catalysis in lithium-air batteries. She says this “novel approach … not only provides new insights for lithium-air batteries,” but also “the template introduced in this work is also readily adaptable for other catalytic systems.”

In addition to Oh, Belcher, and Shao-Horn, the work was carried out by MIT research scientists Jifa Qi and Yong Zhang and postdoc Yi-Chun Lu. The work was supported by the U.S. Army Research Office and the National Science Foundation.

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Graphene Supercapacitors Ready For Electric Vehicles

Automakers are always searching for ways to improve the efficiency, and therefore the range, of electric vehicles. One way to do this is to regenerate and reuse the energy that would normally be wasted when the brakes slow a vehicle down.

There is a problem doing this with conventional batteries, however. Braking occurs over timescales measured in seconds but that’s much too fast for batteries which generally take many hours to charge. So car makers have to find other ways to store this energy.

One of the more promising is to use supercapacitors because they can charge quickly and then discharge the energy just as fast.

Researchers at the Gwangju Institute of Science and Technology in Korea say they have developed a high-performance graphene supercapacitors that stores almost as much energy as a lithium-ion battery, can charge and discharge in seconds and maintain all this over many tens of thousands of charging cycles.

The Koreans say they have perfected a highly porous form of graphene that has a huge internal surface area. This is created by reducing graphene oxide particles with hydrazine in water agitated with ultrasound.

The graphene powder is then packed into a coin-shaped cell, and dried at 140 degrees C and at a pressure of 300/kg/cm for five hours.

The resulting graphene electrode is highly porous. A single gram has a surface area bigger than a basketball court. That’s important because it allows the electrode to accomodate much more electrolyte (an ionic liquid called EBIMF 1 M). And this ultimately determines the amount of charge the supercapacitor can hold.

Santhakumar Kannappan at the Gwangju Institute of Science and Technology have measured the performance of their supercapacitor at a specific capacitance of over 150 Farrads per gram that can store energy at a density of more than 64 Watt hours per kilogram at a current density of 5 Amps per gram.

That’s almost comparable with lithium-ion batteries which have an energy density of between 100 and 200 Watt hours per kilogram.

These supercapacitors have other advantages too. Kannappan and co say they can fully charge them in just 16 seconds and have repeated this some ten thousand times without a significant reduction in capacitance. “These values are the highest so far reported in the literature,” they say.

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Volvo Developing Wireless Charging for Electric Vehicles

The Swedish car manufacturer has announced the development of an energy transfer technology that uses electromagnetic fields. Long term, Volvo sees the technology leading to cordless charging solutions for its hybrid and all-electric vehicles.

In an official press release, Volvo's Vice President for Electric Propulsion Systems, Lennart Stegland, announced that “inductive charging has great potential” and is “a comfortable and effective way to conveniently transfer energy.” Volvo's tests also indicated that the method is safe, although there are currently no common standards for charging vehicles using induction, a fact that makes it difficult to bring it to mainstream consumers in the near future. Nonetheless, Volvo will continue researching the concept and will soon evaluate the feasibility of integrating it into future hybrid and all-electric cars.

Inductive charging uses electromagnetic fields to transfer energy from one source to another. One induction coil, located in the power source, creates an alternating electromagnetic field, while a second coil draws the energy from the first to recharge the vehicle's battery. Charging begins automatically as soon as the vehicle is positioned over the charging apparatus, without requiring the use of cables or plugs. Volvo claims that the technology is already used today in a number of home appliances, such as electric toothbrushes.

The research project was carried out in partnership with Flanders' Drive, an automotive industry think tank in Belgium. The study showed that it is possible to recharge the Volvo C30 Electric without the use of cables in 2 hours and 30 minutes.

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WiTricity Secures Additional $25 Million in Funding

WiTricity announced today it has secured $25 million in Series E financing from new and existing investors, including Intel Capital and Hon Hai/Foxconn, one of the world’s largest consumer electronics manufacturers. The funding will support the company’s growth strategy as it further develops designs and products for wireless charging in the consumer electronics, electric vehicles, defense and medical device industries, as well as allowing WiTricity to pursue other strategic growth opportunities in the wireless power field.

“WiTricity’s vision is to usher in a world where wireless power is so ubiquitous, you never have to think about plugging in again,” said WiTricity CEO Eric Giler. “In securing this funding from our investors we are even more effectively positioned to fulfill that vision and deliver game-changing wireless technology to partners and customers around the globe.”

The announcement marks the next phase in WiTricity’s continued growth as a leader in the wireless power space. According to analyst firm IMS Research, the global market for wireless power will grow 86.5 percent annually to be worth $4.5 billion in 20161. As the inventor of Highly Resonant Wireless Power Transfer, WiTricity is poised to capture that market through existing and new partnerships with major manufacturers including Audi, Mitsubishi, Delphi, Haier, IHI, MediaTek and Thoratec.

With this infusion of $25 million, WiTricity’s investment funding now totals $45 million. In addition, the company recently secured its 50th patent, positioning it even more strongly for growth and success in the global market.

WiTricity have previously announced wireless electric vehicle charging partnerships with Audi, Toyota, Delphi, Mitsubishi and IHI.

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San Diego Gets First Public SAE Fast-Charging Station for EVs

The SAE International DC “Combo” Fast Charge station installation at the Fashion Valley Mall in San Diego is a milestone for plug-in electric vehicles – the first public installation in the U.S. of an industry-coordinated standard for fast charging of plug-in electric vehicles.

The Chevrolet Spark EV, available in California and Oregon, will be the first EV in the U.S. to offer the SAE International fast-charge connector as a vehicle option starting in late December.

“The launch of these new charge stations will help improve the convenience and adoption of electric vehicles because they dramatically reduce the charge time,” said Pamela Fletcher, executive chief engineer of electrified vehicles at General Motors. “The SAE Combo DC fast charge stations are the result of EV industry collaboration to help customers benefit from available public infrastructure.”

The new combined AC and DC charging, or combo, connector is accessible via a single charge port on the vehicle and allows electricity to flow at a faster rate, making EVs more convenient for longer trips and for EV owners who may lack convenient access to overnight home charging.

“San Diego Gas & Electric applauds the collaborative efforts it took to make San Diego home to the world’s first retail SAE DC fast charge station,” said Lee Krevat, director of smart grid and clean transportation for the utility. “Our local drivers that have vehicles equipped with this charging system connector will be the true beneficiaries of this technology.”

Many major automakers including GM, Ford, Chrysler, BMW, Daimler, Volkswagen, Audi and Porsche have announced they will adopt the SAE combo fast charge connector standard. Earlier, many of the world’s major automakers had adopted the SAE’s 120V/240V AC connector standard to assure plug-in vehicles could access all charging infrastructure regardless of vehicle make or model.

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Molten-air battery offers up to 45x higher storage capacity than Li-ion

Researchers at George Washington University have demonstrated a new class of high-energy battery, called a "molten-air battery," that has one of the highest storage capacities of any battery type to date. Unlike some other high-energy batteries, the molten-air battery has the advantage of being rechargeable.

Although the molten electrolyte currently requires high-temperature operation, the battery is so new that the researchers hope that experimenting with different molten compositions and other characteristics will make molten-air batteries strong competitors in electric vehicles and for storing energy for the electric grid.

This ability to store multiple electrons in a single molecule is one of the biggest advantages of the molten-air battery. By their nature, multiple-electron-per-molecule batteries usually have higher storage capacities compared to single-electron-per-molecule batteries, such as Li-ion batteries. The battery with the highest energy capacity to date, the vanadium boride (VB2)-air battery, can store 11 electrons per molecule. However, the VB2-air battery and many other high-capacity batteries have a serious drawback: they are not rechargeable.

The researchers experimented with using iron, carbon, and VB2 as the molten electrolyte, demonstrating very high capacities of 10,000, 19,000, and 27,000 Wh/l, respectively. The capacities are influenced by the number of electrons that each type of molecule can store: 3 electrons for iron, 4 electrons for carbon, and 11 electrons for VB2. In comparison, the Li-air battery has an energy capacity of 6,200 Wh/l, due to its single-electron-per-molecule transfer and lower density than the other compositions while a typical Li-Ion battery has a capacity of approx 600 Wh/l.

Source: Phys.org

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Japan tests 581 km/h Maglev train [VIDEO]

Japan resumes tests on magnetic levitation train intended to travel at speeds up to 581 kilomeres per hour.

Central Japan Railway Co. (JR Tokai) has began full-scale tests of the world's fastest train, the L0 series Maglev.

After completing test drives at 500 kph on the 42.8-kilometer-long Yama-nashi maglev test line stretching from Uenohara to Fuefuki in Yamanashi Prefecture to check such factors as durability, JR Tokai plans to start commercial operations between Tokyo and Nagoya in 2027.

Following a departure ceremony, Land, Infrastructure, Transport and Tourism Minister Akihiro Ota and JR Tokai chairman Yoshiyuki Kasai went for a 505 kph ride on the train.

“We were able to speak normally inside the maglev train [thanks to reduced noise levels]. I’m convinced this is world-class technology,” Ota said.

Testing will take place until fiscal 2016, during which time JR Tokai plans to switch to testing a 12-car train, which will be used on the commercial run.

The link is to be stretched west to Osaka by 2045.

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200,000 Fast-Charging Stations for Electric Vehicles by 2020

Total fast-charging stations for EVs are set to reach 199,000 locations globally in 2020, up from just 1,800 in 2012. The number of these stations, meanwhile, is anticipated to rise more than threefold in 2013 to 5,900 and then nearly triple to 15,200 in 2014. Overall growth will continue at a rapid pace through 2020.

Hard charging

"The length of time it takes to recharge an EV continues to be one of the major stumbling blocks inhibiting the widespread adoption of electric vehicles," said Alastair Hayfield, associate research director at IHS Automotive. "Compared to the time it takes to refuel an internal combustion engine (ICE) vehicle, the recharge time for EVs is incredibly slow-at about four hours to charge a 24 kilowatt-hour (kWh)-capacity battery using a 6.6 kW on-board charger. If EV auto manufacturers could overcome this obstacle, it could lead to a high rate of adoption from environmentally minded consumers as well as those seeking to cut gasoline expenses. That's where fast charging comes in."

Hooked up to a fast-charging system, which offers a high-voltage DC charge instead of a slower AC charge, a vehicle can be fully charged in as little as 20 minutes. This could be a major step toward EVs becoming generally equivalent to ICE vehicles when it comes to refueling.

"IHS believes fast charging is a necessary step to promote higher adoption of EVs, but there will need to also be better consumer education regarding behavioral changes that may need to happen when owning an electric vehicle-such as charging overnight or at work," Hayfield said.

Japanese standard charges ahead

One fast-charging standard designed for electric vehicles is dubbed CHAdeMO, a primarily Japanese-backed technology. The major proponents of the technology are Japanese automotive OEMs-including Toyota, Nissan, Mitsubishi; and Japanese industrial giants-including Fuji Heavy Industries Ltd., Tokyo Electric Power Co. and more.

CHAdeMO, roughly translated as "charge for moving," began deployment in 2009 in order to accelerate the adoption of electric vehicles in Japan, where EVs have found positive reception. Today there are as many as 2,445 CHAdeMO fast chargers in operation and more than 57,000 CHAdeMO-compatible EVs around the world. This accounts for as much as 80 percent of all electric vehicles on the road, especially given the high concentration of EVs coming from Japan in the form of the Nissan Leaf, Mitsubishi i-MiEv, Hondo Fit EV and more.

One size charges all

A competing solution to CHAdeMO, aptly named the combined charging system (CCS), offers electric vehicle owners the option of having a single charging inlet that can be used for all available charging methods. That includes 1-phase charging at an AC power source, high-speed AC charging with a 3-phase current connector at home or at public charging stations, DC charging at conventional household installation and DC fast charging at power-charging stations globally.

CCS, which was submitted for international standardization in January of 2011, has garnered the support of Audi, BMW, Daimler, Chrysler, Ford, GM, Porsche and Volkswagen. Already BMW, GM and Volkswagen have announced they will introduce fast-charging EVs based on the CCS standard sometime this year.

Tesla vies to electrify the market

Tesla Motors, the California company most notable for the all-electric Tesla Model S, is driving a third method for fast charging. Tesla is developing its own proprietary network of fast chargers in the U.S. Dubbed "Superchargers," the chargers operate at a higher power rating than current CHAdeMO or CCS chargers, and also have a proprietary plug interface, which means that only Tesla vehicles can use them.

"In addition to the proprietary technology, the charging stations are free to use for Tesla owners, and there are plans to power all stations using photovoltaics," Hayfield said. "These Superchargers represent a powerful proposition for Tesla-drivers can charge faster, have U.S.-wide coverage by 2015 and will charge for free for life. This triple threat will aim to lock drivers into the Tesla experience, and also will give Tesla a perceived advantage over other original equipment manufacturers competing in the same market.

Future charge

Looking ahead to the future of EVs, it's clear that DC charging is becoming the favored means for supporting rapid, range-extension electric vehicles. But it is less clear as to whether CHAdeMO or CCS will win the battle for the consumer.

Japan will continue to utilize CHAdeMO, while Germany is set on using CCS; other nations likely will also utilize CCS as well, since it supports slow-charging. But no matter which solution is used, DC-based fast charging is critical to promoting consumer approval and interest in EVs.