Electron-transferring complexes may give electric vehicles ability to cover 400 to 500 miles per charge
Lithium-air batteries are seen as one of the most promising technologies for future energy storage applications. Capable in the theory of storing 10 times more energy than lithium ion batteries and much lower in weight, they are still in development, with their stability and efficiency still not matching expectations. Battery researchers are trying to find catalysts that can increase the rate of the chemical reactions inside the battery, which increases their ability to hold and discharge energy.
Engineers at the University of Illinois at Chicago (UIC) are working on two-dimensional compounds of transition metals – the elements that occupy the central block of the periodic table, which tend to have a large number of electrons per atom that are capable of becoming involved with bonding and electrical activity – with non-metals.
In the journal Advanced Materials, Amin Salehi-Khojin and colleagues from UIC’s College of Engineering describe how a type of compound called transition metal dichalcogenides (TMDCs) enabled lithium-air batteries to hold 10 times more energy than batteries using traditional catalysts. Chalcogenides are compounds incorporating elements of group 16 in the periodic table, including oxygen, sulphur, selenium and tellurium.
Lithium-air batteries use an anode made of pure lithium with external ambient air as the cathode, typically with an aqueous electrolyte. The catalyst is generally dissolved in the electrolyte, and gold and platinum are used conventionally. TMDCs, especially those with two-dimensional shapes, have very high electronic conductivity and fast electron transfer, and according to Salehi-Khojin are bi-functional: that is, they are active both in charging and discharging the battery.
The Chicago team, collaborating with other engineers at Purdue University, Washington University in St Louis and materials scientists at the Argonne National Laboratory, used a battery with an ionic-liquid electrolyte based on dimethyl sulphoxide (DMSO), which is commonly used as a solvent that can dissolve materials containing either charged and uncharged components.
“The 2D TDMCs and the ionic liquid electrolyte that we used acts as a co-catalyst system that helps the electrons transfer faster, leading to faster charges and more efficient storage and discharge of energy,” Salehi-Khojin said.
Salehi-Khojin’s team synthesised 15 TMDCs including vanadium ditellurate and diselenate and molybdenum and niobium disulphides, and investigated their activity in an electrochemical system mimicking a lithium-air battery.
“In their 2D form, these TMDCs have much better electronic properties and greater reactive surface area to participate in electrochemical reactions within a battery while their structure remains stable,” said Leily Majidi, a graduate student in the UIC College of Engineering and first author of the paper. “Reaction rates are much higher with these materials compared to conventional catalysts.”
Salehi-Khojin believes that these technologies could become very useful. “We are going to need very high-energy density batteries to power new advanced technologies that are incorporated into phones, laptops and especially electric vehicles,” he said. “Currently, electric vehicles average about 100 miles per charge, but with the incorporation of 2D catalysts into lithium-air batteries, we could provide closer to 400 to 500 miles per charge, which would be a real game-changer. These new materials represent a new avenue that can take batteries to the next level, we just need to develop ways to produce and tune them more efficiently and in larger scales.”
Is this another hopeful development to spin us along the electric golden road. Are they even considering the CO2 profile of the manufacturing process and materials used. The average of 1 ton of CO2 for every 5 KWh of battery capacity for the present generation of Lithium ion batteries means we are certainly all going to drown in CO2. We will just get to the end game twice as quick as with conventional fuels. A current 100KWh battery creates 20 Tons of CO2 during manufacture compared with conventional diesel cars over a 17 year life generating the same amount of CO2.
The Battery still has to be charged to go anywhere. CO2 of Generation that the bonus?
I think a fact check is required..
The Union of Concerned Scientists did the best and most rigorous assessment of the carbon footprint of Tesla’s and other electric vehicles vs internal combustion vehicles including hybrids. They found that the manufacturing of a full-sized Tesla Model S rear-wheel drive car with an 85 KWH battery was equivalent to a full-sized internal combustion car except for the battery, which added 15% or one metric ton of CO2 emissions to the total manufacturing.
However, they found that this was trivial compared to the emissions avoided due to not burning fossil fuels to move the car. Before anyone says “But electricity is generated from coal!”, they took that into account too, and it’s included in the 53% overall reduction.
https://www.forbes.com/sites/quora/2016/04/22/the-carbon-footprint-of-tesla-manufacturing/#34f1fa366096
Yes, yes, quite so, to all of the above, however, algae has a negative carbon footprint, leftovers can feed hogs, or even cows, and does not require traditionally arable land area for production, seems someone is laser focused through blinders on this “green” technology. There are saline deep aquifers that can be accessed using wind/solar, and much of the algae production water is used over and over if more modern techniques of containment are utilized. Thus the water requirement is met, not a great deal of land is required (about 1/7 the land mass equivalent of Colorado for the entire US fleet), and if done offshore, there are additional benefits.
There seems to be a lot of highly conflicting information on this subject. On suspects the balance falls somewhere in the middle. The article below states that the co2 generated by the manufacture of Lithium ion batteries is around 0.2 tonnes per kWh. That works out to 15 tonnes of co2 for a 75kWh battery for a Tesla, a figure that is somewhat in excess of the 1 tonne that the Forbes article states. Your mileage may vary, as they say.
https://www.thegwpf.com/new-study-large-co2-emissions-from-batteries-of-electric-cars/