Aug 04, 2023

Is It Possible To Build Smaller Yet Long

Lithium-ion batteries have now become indispensable to households across the world. With their excellent energy storage, lightweight, and recharging potential, these batteries are now finding their rampant usage in Electric Vehicles (EVs) and other household energy storage devices.

But is it possible to build more long-lasting and smaller Lithium-ion batteries of equal or more capacity? The answer is yes. Researchers worldwide are now working towards increasing the capacity of Lithium-ion batteries and paving the way to make them lighter and smaller.

These batteries comprise two terminals-a cathodes (positive charge terminal) and anode (negatively charged terminal), an electrolyte (a semi-fluid element), and a separator in the midway. Usually, the cathode side is Lithium around it, while the anode comprises Graphite. The whole working of these Li-ion batteries revolves around the movement of Li ions and electrons during charging and discharging.

These are also called Lithium oxygen batteries. They can store ten times more energy than conventional Lithium-ion batteries. Their energy capacities are comparable with the energy offered by fossil fuels. However, they have yet to become a viable solution to be commercially used.

As per the design, in these batteries, one of the electrodes is made up of Lithium, while the other side is made up of a gas diffusion electrode. When these batteries are used, Lithium ions move from the cathode across the electrolyte towards the anode, where it combines with oxygen, forms Lithium oxide, and generate electricity.

However, the good news is that a group of researchers are working to make it successful. A team from the University of Oldenburg in Germany has started working towards extending the life of these batteries and making these Lithium oxygen batteries a reality. The project has been named Alternative Materials and Components for aprotic lithium-oxygen batteries: chemistry and stability of inactive components (AmaLiS 2.0). The Federal Ministry of Education and Research granted the project team 1.1 million euros.

The team is working towards testing a new idea where they have planned to separate the cathode and anode using a membrane coated on both sides. In addition, the team wants to use two different electrolytes for the two sides of the battery. Finally, they also want to try Titanium Carbide as a material for one of the electrodes.

Besides the works on Lithium-oxygen batteries, several researchers, EVs, and other companies are working towards replacing Graphite at the anode with Silicon, another crucial element. Silicon has the advantage of holding up Lithium ions ten times more weight than Graphite when used in an anode.

But there are technical hurdles that have prevented its usage despite its benefits. First, its use is often blamed for the volume expansion of the anode when loaded with Lithium ions, which often leads to material fracture. It is attributed to the contraction and expansion of the anode with the use of Silicon.

However, the good news is that the researchers are working towards a breakthrough in this technology. For example, General Motors and OneD Battery Sciences are working on a Silicon nanotechnology anode. The team claimed these restructured batteries would be used in the Mercedes G Class SUV by the end of 2026. Similarly, Group14 Technologies have vowed to have its silicon-powered battery setup in its Porsche EV by 2024.

According to researchers, Silicon has unique features like its long-lasting capacity and fast charging, which can make future EVs more affordable, effective, and even smaller. Moreover, with its vast abundance, its usage as an alternative to Graphite can also make the manufacturers independent of Graphite which is still found in very few countries like China.

Earlier, even the mega EV brand of Tesla also tried to increase the capacity of its batteries by adding a meager 5 percent of Silicon to its battery anode. Moreover, several other researchers and companies are investing in research and development to use Silicon instead of Graphite to reduce import dependency and improve the efficiency of the Lithioum-ion batteries.

The Li-ion batteries Advancements in progress