Tag Archives: potential

Researchers From NREL Discovered New Method To Develop Rechargeable Magnesium-metal Battery

A team of researchers from National Renewable Energy Laboratory (NREL) has discovered a new method for developing a rechargeable non-aqueous magnesium-metal battery. A proof-of-concept paper published in Nature Chemistry. It described how the scientists pioneered a method to enable the reversible chemistry of magnesium metal in the noncorrosive carbonate-based electrolytes and tested the concept in a prototype cell. The technology possesses many high potential advantages over conventional lithium-ion batteries. Some upgrades over Li-ion battery with this new kind of battery will be, higher energy density, greater stability, and lower cost.

magnesium-metal batteries
magnesium-metal batteries

NREL researchers Seoung-Bum Son, Steve Harvey, Andrew Norman, and Chunmei Ban are co-authors of the Nature Chemistry white paper, “An Artificial Interphase Enables Reversible Magnesium Chemistry in Carbonate Electrolytes” working with a Time-of-flight secondary ion mass spectrometry. The device enables them to investigate material degradation and failure mechanisms at the micro- to nano-scale.

Chunmei Ban, a scientist in NREL’s Materials Science department and corresponding author of the paper, said,

Being scientists, we’re always thinking: what’s next? The dominant lithium-ion battery technology is approaching the maximum amount of energy that can be stored per volume, so there is an urgent need to explore new battery chemistries that can provide more energy at a lower cost.

Seoung-Bum Son, a former NREL postdoc and scientist at NREL and first author of the paper, thinks this finding will provide a new avenue for magnesium battery design.

An electrochemical reaction powers a battery as ions flow through a liquid (electrolyte) from the negative electrode (cathode) to the positive electrode (anode). For batteries using Lithium, the electrolyte is a salt solution containing lithium ions. It’s also important to make the chemical reaction reversible for the battery to recharge again.

Magnesium (Mg) batteries theoretically contain almost twice as much energy per volume as of lithium-ion batteries. But previous research confronted an obstacle. The chemical reactions of the conventional carbonate electrolyte created a layer on the surface of magnesium that prevented the battery from recharging. The magnesium ions could flow in a reverse direction through a highly corrosive liquid electrolyte, but that blocked the possibility of a successful high-voltage magnesium battery.

The researchers developed an artificial solid-electrolyte interphase from polyacrylonitrile and magnesium-ion salt that protected the surface of the magnesium anode. This protected anode and significantly improved performance of the cell.

In addition to being more readily available than lithium, magnesium has other advantages over the more established battery technology. Firstly, magnesium releases two electrons which is higher lithium’s one, thus giving it the potential to deliver nearly twice as much energy as lithium. And second, magnesium-metal batteries do not experience the growth of crystals that can cause short circuits and consequently dangerous overheating and even fire, making magnesium batteries much safer than lithium-ion batteries.

Newly Developed Internal Temperature Sensor For Li-ion Battery Enables 5x Faster Charging

Researchers at the University of Warwick in the UK have developed sensors which measure the internal temperature and electrode potential of Lithium batteries. The technology is being developed by the Warwick Manufacturing Group (WMG) as a part of a battery’s normal operation. More intense testings have been done on standard commercially available automotive battery cells.

Researchersdeveloped a sensor to measure the internal termperature and electrode potential of lithum batterry
Researchers developed a sensor to measure the internal temperature and electrode potential of lithium battery

If a battery overheats it becomes a risk for critical damage to the electrolyte, breaking down to form gases that are both flammable and can cause significant pressure build-up inside the battery. On the other hand, overcharging of the anode can lead to Lithium electroplating, forming a metallic crystalline structure that can cause internal short circuits and fires. So, overcharging and overheating of a Li-ion battery is hugely damaging to the battery along with the user.

The researchers at Warwick developed miniature reference electrodes and Fiber Bragg Gratings (FBG) threaded through a strain protection layer. An outer coat of Fluorinated Ethylene Propylene (FEP) was applied over the fiber, ensuring chemical protection from the corrosive electrolyte. The end result is a sensor which has direct contact with all the key components of the battery. The sensor can withstand electrical, chemical and mechanical stress faced during the normal operation of the battery while still giving accurate temperature and potential readings of the electrodes.

The device includes an in-situ reference electrode coupled with an optical fiber temperature sensor. The researchers are confident that similar techniques can also be developed for use in pouch cells. WMG Associate Professor Dr. Rohit Bhagat said,

This method gave us a novel instrumentation design for use on commercial 18650 cells that minimizes the adverse and previously unavoidable alterations to the cell geometry,

The data from these internal sensors are much more precise than external sensing. This has been shown that with the help of these new sensors, Lithium batteries that are available today could be charged at least five times faster than the current rates of charging.

This could bring huge benefits to areas such as motor racing, gaining crucial benefits from being able to push the performance limits. This new technology also creates massive opportunities for consumers and energy storage providers.