High-performance lithium ion batteries face a major problem: Lithium will eventually start to run out as batteries are deployed in electric cars and stationary storage units. Researchers from Empa and ETH Zurich have now discovered an alternative: the “fool’s gold battery”. It consists of iron, sulfur, sodium and magnesium – all elements that are in plentiful supply. This means that giant storage batteries could be built on the cheap and used stationary in buildings or next to power plants, for instance.
There is an urgent need to search for low-priced batteries to store electricity. Intermittency of green electricity is affecting the power grids, calling for stationary storage units to be connected into a smart grid., Electric cars are of increasing popularity, but are still to explensive.
Efficient lithium ion batteries we know are not suitable for large-scale stationary storage of electricity; they are just too expensive precious lithium is too scarce. A cheap alternative is called for – a battery made of inexpensive ingredients that are available in abundance. But electrochemistry is a tricky business: Not everything that’s cheap can be used to make a battery.
Safe, durable and affordable
Maksym Kovalenko, Marc Walter and their colleagues at Empa’s Laboratory for Thin Films and Photovoltaics have now managed to pull off the unthinkable: by combining a magnesium anode with an electrolyte made of magnesium and sodium ions. Nanocrystals made of pyrite – more commonly known as fool’s gold – serve as the cathode. Pyrite is crystalline iron sulfide. The sodium ions from the electrolyte migrate to the cathode during discharging.
When the battery is recharged, the pyrite re-releases the sodium ions. This so-called sodium-magnesium hybrid battery already works in the lab and has several advantages: The magnesium as the anode is far safer than highly flammable lithium. And the test battery in the lab already withstood 40 charging and discharging cycles without compromising its performance, calling for further optimization.
The biggest advantage, however, is the fact that all the ingredients for this kind of battery are easily affordable and in plentiful supply: Iron sulfide nanocrystals, for instance, can be produced by grinding dry metallic iron with sulfur in conventional ball-mills. Iron, magnesium, sodium, and sulfur are amongst hold 4th, 6th, 7th and 15th place by the abundance in the Earth’s crust(by mass).
One kilogram of magnesium costs at most four Swiss francs, which makes it 15 times cheaper than lithium. There are also savings to be made when it comes to constructing the cheap batteries: Lithium ion batteries require relatively expensive copper foil to collect and conduct away the electricity. For the fool’s gold battery, however, inexpensive aluminum foil is perfectly sufficient.
Potential for storing the electricity produced annually at Leibstadt power station
The researchers primarily see potential in their development for large network storage batteries. The fool’s gold battery is not suitable for electric cars – its output is too low. But wherever it boils down to costs, safety and environmental friendliness, the technology is a plus. In their paper recently published in the journal Chemistry of Materials, the Empa researchers propose batteries with terawatts of storage capacity.
Such a battery might be used to temporarily store the annual production from the Swiss nuclear power station in Leibstadt, for instance. “The battery’s full potential has not been exhausted yet,” says Kovalenko, who teaches as a professor at ETH Zurich’s Department of Chemistry and Applied Biosciences alongside his research at Empa.
“If we refine the electrolytes, we’re bound to be able to increase the electric voltage of the sodium-magnesium hybrid cell even further and to extend its cycling life.” He adds: “We also look for investors willing to support research into such post-Li-ion technologies and bring them to the market”.
Rainer Klose | EMPA
Data use draining your battery? Tiny device to speed up memory while also saving power
14.12.2018 | Purdue University
Studying how unconventional metals behave, with an eye on high-temperature superconductors
13.12.2018 | Princeton University
Researchers from the University of Basel have reported a new method that allows the physical state of just a few atoms or molecules within a network to be controlled. It is based on the spontaneous self-organization of molecules into extensive networks with pores about one nanometer in size. In the journal ‘small’, the physicists reported on their investigations, which could be of particular importance for the development of new storage devices.
Around the world, researchers are attempting to shrink data storage devices to achieve as large a storage capacity in as small a space as possible. In almost...
The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.
Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...
What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...
A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.
The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...
A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.
Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...
12.12.2018 | Event News
10.12.2018 | Event News
06.12.2018 | Event News
17.12.2018 | Physics and Astronomy
17.12.2018 | Architecture and Construction
17.12.2018 | Life Sciences