From suffocating smog to futuristic fuel: Air purifier turns pollution into power

A device that generates hydrogen gas while purifying air could one day be used to simultaneously combat urban pollution and provide an environmentally friendly fuel source for vehicles.

Developed by scientists from the University of Antwerp and the University of Leuven in Belgium, the device only requires light to work, making it a promising technology for cities looking to improve their air quality.

“We use a small device with two rooms separated by a membrane,” said study lead author professor Sammy Verbruggen, from the Universities of Antwerp and Leuven.

“Air is purified on one side, while on the other side hydrogen gas is produced from a part of the degradation products. This hydrogen gas can be stored and used later as fuel, as is already being done in some hydrogen buses, for example. “

The device is currently only available as a prototype, but the researchers plan to scale it up to be used in industrial-level settings, where it could be used to combat the ever-growing problem of urban air pollution.

Air pollution in California, the US

The device relies on specific nanomaterials within the its membrane, which act as a catalyst to help convert air pollution into hydrogen.

Previously these materials have been used to convert water into hydrogen, however the researchers found that using polluted air was not only also possible, but potentially more effective.

“These catalysts are capable of producing hydrogen gas and breaking down air pollution,” explained Verbruggen. “In the past, these cells were mostly used to extract hydrogen from water. We have now discovered that this is also possible, and even more efficient, with polluted air.”

With a prototype now demonstrated, the researchers plan to develop an industrial-scale version.

“We are currently working on a scale of only a few square centimetres. At a later stage, we would like to scale up our technology to make the process industrially applicable,” explained Verbruggen.

“We are also working on improving our materials so we can use sunlight more efficiently to trigger the reactions. “

The prototype device. Image courtesy of UAntwerpen and KU Leuven

Air pollution is a problem attracting increasing attention in much of the world. The UK government, for example, is currently being sued for repeatedly failing to act on the problem, having taken little action after repeatedly breaching legal air pollution limits in many of its urban areas.

A growing body of research is also drawing links between air pollution and poor health. A study published in ACS Nano in April suggested that nanoscale particles in polluted air could be contributing to heart disease and strokes, while a study by Yale School of Public Health found that air pollution contributes to higher levels of depression.

Other conditions linked to poor air quality include lung cancer and respiratory diseases such as asthma.

It is hoped that the research, which is published today in the journal ChemSusChem, could help to combat the problem.

Breakthrough battery concept set to provide electric vehicles with 1,000km range

A new battery concept could enable electric vehicles to reach ranges of up to 1,000km. Developed by the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden, Germany, the EMBATT system transfers bipolar principles used in fuel cells to lithium batteries.

“We use our expertise in ceramic technologies to design the electrodes in such a way that they need as little space as possible, save a lot of energy, are easy to manufacture and have a long life,” explained Dr Mareike Wolter, project manager at Fraunhofer IKTS.

The concept is designed to address a few key problems that traditional battery systems face. Depending on the model, electric cars are equipped with hundreds to thousands of separate battery cells. Each of these cells is surrounded by a housing, which connects to the car with terminals and cables, and monitored by sensors.

The issue stems from the fact that the housing and contacting take up more than 50% of the space, meaning that the ideal of densely packed cells is unachievable. Additionally, electrical resistance, which reduces the power, is generated at the connections of the small-scale cells. However, the EMBATT system significantly reduces or eliminates these problems by a seemingly simple method.

A pilot version of the bipolar electrode, which is central to the revolutionary design. Image courtesy of Fraunhofer IKTS

Using the bipolar principle applied to fuel cells, individual battery cells are not strung separately side-by-side in small sections; instead, they are stacked directly one above the other across a large area. Doing so entirely removes the structure for housing and contacting, allowing far more batteries to fit into the car.

Furthermore, the direct connection of the stacked batteries allows current to flow over the entire surface of the battery. Doing so considerably reduces any electrical resistance and is largely helped by the batteries’ electrodes, which are designed to release and absorb energy very quickly.

The principle component of the battery is the bipolar electrode – a metallic tape that is coated on both sides with ceramic storage materials. One side of the tape operates as the cathode, the other as the anode. It is this electrode that functions as the heart of the battery to store energy.

The Tesla Model S 100D is thought to have one of the best ranges of current commercially available electric vehicles, at up to 683km (424 miles). Image courtesy of Tesla

The electrode is in no small part the result of the researcher’s expertise in ceramics, using ceramic materials as powders that are then mixed with polymers and electrically conductive materials to form a suspension. This suspension is then applied to the tape in a roll-to-roll process.

“This formulation has to be specially developed – adapted for the front and back of the tape, respectively,” Wolter explained. “One of the core competencies of our institute is to adapt ceramic materials from the laboratory to a pilot scale and to reproduce them reliably”.

Going forward, the researchers plan to develop even larger battery cells and work on installing them into electric vehicles. They and their partners are aiming for initial vehicle tests in 2020.