U Alberta team develops hybrid sodium-ion capacitor; intermediate in energy power between ultracaps and batteries

15 December 2014

A team led by researchers from the University of Alberta (Canada)
Scientists has developed a hybrid sodium-ion capacitor (NIC) using active materials in both the anode and the cathode derived entirely from peanut shells—a green and highly economical waste globally generated at more than 6 million tons per year. The hybrid NIC stores charge both electrostatically and electrochemically, and sits between ultracapacitors and batteries in terms of power (ultracaps) and energy (batteries) storage capability.

According to their paper, published in the RSC journal Energy Environmental Science, the electrodes deliver among the most promising sodiation capacity–rate capability–cycling retention combinations reported in the literature. The resultant NIC also offers an advanced cyclically stable combination of energy and power, not only in respect to previously developed sodium-ion capacitors, but also as compared to Li-ion capacitors (LICs).

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The NIC features an ion-adsorption cathode and an ion-intercalation anode.

• The ion-adsorption cathode, based on Peanut Shell Nanosheet Carbon (PSNC), displays a hierarchically porous architecture; a sheet-like morphology down to 15 nm in thickness; a surface area on par with graphene materials (up to 2396 m2 g⁻¹); and high levels of oxygen doping (up to 13.51 wt%). Scanned from 1.5–4.2 V vs. Na/Na⁺, PSNC delivers a specific capacity of 161 mAh g⁻¹ at 0.1 A g⁻¹ and 73 mAh g⁻¹ at 25.6 A g⁻¹.

• The low-surface-area ion-intercalation Peanut Shell Ordered Carbon (PSOC) anode delivers a total capacity of 315 mAh g⁻¹ with a flat plateau of 181 mAh g⁻¹ occurring below 0.1 V (tested at 0.1 A g⁻¹), and is stable at 10,000 cycles (tested at 3.2 A g⁻¹).

The assembled NIC operates within a wide temperature range (0–65 °C), yielding at room temperature (by active mass) 201, 76 and 50 Wh kg⁻¹ at 285, 8,500 and 16,500 W kg⁻¹, respectively. At 1.5–3.5 V, the hybrid device achieved 72% capacity retention after 10,000 cycles tested at 6.4 A g⁻¹, and 88% after 100,000 cycles at 51.2 A g⁻¹.

In a review of the technology in the RSC’s Chemistry World, Professor David Mitlin, who led the research, explained:

In conventional batteries the cathode often limits performance and so what people are starting to do is swap regular cathodes for supercapacitor cathodes. Ions are adsorbed onto the surface of the cathode in an NIC, which avoids the degradation seen in batteries due to ion absorption into the bulk.

In addition to being easy to source and being inexpensive, peanut shells (both inner and outer) offer structural characteristics desirable for anode and cathode materials, respectively.

Resources

• Jia Ding, Huanlei Wang, Zhi Li, Kai Cui, Dimitre Karpuzov, Xuehai Tan, Alireza Kohandehghan and David Mitlin (2015) “Peanut shell hybrid sodium ion capacitor with extreme energy–power rivals lithium ion capacitors” Energy Environ. Sci. doi: 10.1039/C4EE02986K

BMW to show 360-degree collision avoidance and fully-automated remote parking in multi-story garages at CES

15 December 2014

The driver has the i3 park itself in a multi-story garage using a smartwatch. Click to enlarge.

BMW will demonstrate new driver assistance and automated control functions including 360-degree collision avoidance and fully-automated parking in multi-story parking garages at the upcoming Consumer Electronics Show (CES) 2015 in January.

The platform for 360-degree collision avoidance is secure position and environment recognition; the research vehicle is a BMW i3. Four advanced laser scanners record the environment and reliably identify impediments such as columns, for example in a multi-story parking garage. If the vehicle approaches a wall or a column too quickly, the system brakes automatically to prevent the threat of collision. The vehicle is brought to a standstill very precisely with centimeters to spare.

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If the driver steers away from the obstacle or changes direction, the system releases the brakes. This system relieves the burden on the driver in an environment with poor visibility and makes a further contribution to enhanced safety and comfort. Like all BMW assistance systems, this research application can be overridden at any time by the driver.

The fully automated Remote Valet Parking Assistant in the BMW i3 research vehicle combines information from the laser scanners with the digital site plan of a building—such as a parking garage. If the driver uses the Smartwatch to activate the fully-automated Remote Valet Parking Assistant, the system will steer the vehicle independently through the levels, while the driver has already got out of the car.

The fully automated Remote Valet Parking Assistant recognizes the structural features of the car park and equally reliably steers round any obstacles that appear unexpectedly—such as incorrectly parked vehicles. Once the BMW i3 has arrived at the parking space, the vehicle locks itself and waits to be called by Smartwatch and voice command. The fully automated Remote Valet Parking Assistant then calculates the exact time until the driver arrives at the car park and starts up the BMW i3 so that it arrives at the car park exit at exactly the right time.

Research i3 parking itself. Click to enlarge.

BMW has succeeded in achieving fully automated control of the vehicle by connecting up vehicle sensor systems and a digital site plan. This avoids dependence on the GPS signal, which is not at all precise in multi-story garages. Alongside the laser sensors, the research vehicle also has the processing units and necessary algorithms on board and this means it can determine its exact position in the car park, monitor the environment perfectly, and carry out independent and fully automated navigation. It is not necessary to provide car parks, for example, with complex infrastructure in order to allow cars to orientate and navigate around the area safely.

Research i3 and Remote Valet parking. Click to enlarge.

Ongoing work on autonomous driving. As early as October 2009, the BMW Group gave a highly automated demonstration of driving round the North Loop of the Nürburgring on an ideal line in the precursor research project BMW Track Trainer. Later on, the BMW Track Trainer developed by engineers from BMW Group Research and Engineering demonstrated its performance on the race tracks at Laguna Seca, Zandvoort and Valencia, and back home on the Hockenheimring and the Lausitzring. The researchers gathered some important practical experience under extreme conditions at these venues for vehicle control and positioning.

Additional important findings were also provided by the research project entitled BMW Emergency Stop Assistant. If the driver collapses, for example in a medical emergency such as a heart attack, the vehicle changes to highly automated mode and can steer safely to the side of the road and initiate an emergency call.

In the middle of 2011, a test vehicle from the BMW Group drove along the A9 motorway from Munich towards Nuremberg without any interventions from the driver. Since then, this research prototype has been consistently developed. The test vehicle brakes, accelerates and overtakes entirely independently. These interventions are carried out in response to the momentary traffic situation in a speed range from 0 to 130 km/h (81 mph) and in compliance with the highway code. BMW prototypes have now driven some 20,000 test kilometers (12,400 miles). The vehicle is equipped with sensor systems like lidar, radar, ultrasound and camera recording on all sides.

Since January 2013, the BMW Group has been working with international automobile supplier Continental with the aim of moving the project forward. The overarching goal of the research partnership is to lay the groundwork for highly automated drive functions up to the year 2020 and beyond.

Assistance systems increase safety and comfort in road traffic, although the degree of driver support varies. The highest level of automation is provided by fully automated assistance systems.

Drive functions are fully automated if they no longer need to be monitored by the driver. There is no longer even any need for the driver to be in the vehicle—as in the case of the fully automated Remote Valet Parking Assistant.

The precursors for fully automated driving are highly automated systems which do not need to be monitored continuously by the driver. They take over the linear steering (forward and reverse motion) and transverse steering (sideways motion with the steering wheel) of the vehicle.

In contrast to fully automated systems, partially automated systems take control of linear and transverse steering of the vehicle (e.g. Congestion Assistant), but they need to be monitored at all times by the driver.

Assisted systems (e.g. ACC) in turn only provide support for the driver in linear or transverse steering.

Airbus forecasts China becoming civil aviation market juggernaut: 5,300 new aircraft over 20 years; Nº 1 in domestic traffic in 10; top international market

15 December 2014

Airbus forecasts that China will need more than 5,300 new passenger aircraft and freighters from 2014 to 2033, with a total market value of US$820 billion. That represents 17% of the world total demand for over 31,000 new aircraft in the next 20 years.

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According to Airbus’ 2014-2033 Global Market Forecast, new deliveries of passenger and freight aircraft for China will be 5,363 over the next 20 years, including 3,567 single aisle aircraft, 1,477 twin-aisles and 319 very large aircraft.

China will become the leading country for passenger air traffic, for both domestic and international markets as the passenger traffic in China will grow well above the world average.

Domestic air traffic in China will become the world’s number one within 10 years. China will overtake the United States of America in 2023, in terms of the number of passengers and in 2027, in terms of RPK (Revenue Passenger Kilometer). In the next 20 years, the forecast average annual growth rate for the domestic Chinese market is 7.1% but will grow even faster over the next 10 years at 8.3% on average per year. By 2033, the domestic Chinese market will remain the largest flow, representing 11.9% of world traffic in terms of RPK.

During the period between 2013 and 2023, the average annual growth rate for international traffic from/to mainland China will be 8.1%, according to the forecast. Four out of the 20 largest flows (RPK) will be from/to PRC. The average annual growth rate for markets between emerging Asian countries and PRC is 7.5%, for routes between PRC and the USA is 6.6%, while the routes between Western Europe and PRC is 5.6%.

Domestic passenger traffic in Mainland China has more than quadrupled over the last 10 years, and it will become the world’s number one aviation market within the next 10 years. Airbus’ share of the in-service fleet of aircraft over 100 seats on the Chinese mainland has reached 50 per cent in 2013. In the next 20 years, the greatest demand for passenger aircraft will come from China.

Drivers of China’s dynamic air transport growth include the country’s long-term economic development. The average annual economic growth in China is forecast at 7.4% between 2013 and 2023. China will become the world’s biggest economy in 2023, with its GDP accounting for 19% of the world’s total.

The urbanization of China is one of the major driving forces for the country’s economic growth. The urban population in China’s mainland was 711 million in 2013, representing 54% of the total population. The urban population will grow to 1,014 million in 2033, representing 71% of the population.

Average wages in China have increased five-fold in the past decade and they will continue to rise in the years ahead and fuel higher levels of disposable income and private consumption, which is expected to account for 41% of Chinese GDP in 2023.