One thing that I’ve learned about batteries is they’re complicated. We can’t throw them recklessly because they contain hazardous and scarce materials, we also need them although they’re not exactly sustainable.
But, with the power of technology and the mind of scientists, we might have a new battery made from lithium-sulfur cells. This type is claimed to offer five times the battery life compared to the conventional, good old, lithium-ion battery.
An international team of scientists working at Melbourne Monash University believe that a new type of bonding architecture is able to overcome the hurdle of batteries’ short lifespan. This means that there will be battery charge/discharge efficiency in a lithium-sulfur battery that could keep a smartphone charged for days or drive an electric vehicle for more than 1000km without recharging.
”Ironically, a main challenge to mass adoption of lithium-sulfur batteries until now, has been that the storage capacity of sulfur electrode is so large that it cannot manage the resultant stress. Instead, it breaks apart, in the same way we might when placed under stress,” said study lead author, Dr Mahdokht Shaibani.
Fortunately, the newer experiments have resulted efficiency of 99% over 200 cycles of the lithium-sulfur battery. According to Shaibani, this result “is unprecedented for such high capacity electrodes” to his team’s best knowledge.
After this experiment, the team’s next moves are more testing in order to ensure the longevity of the technology. Once everything is set, the batteries will be tested and installed in electric cars (EV) first. It seems that commercialising this type of battery might take a while, but hey, at least we have an opening to that.
For now, the scientists are currently filling a patent for the lithium-sulfur batteries, which alongside the performance claims, is also said to be cheaper and better for the environment. As you know, lithium-ion batteries are made from lithium, cobalt, nickel and other scarce metals that have to be mined and extracted, putting a strain on the world’s supply of these metals.
Moreover, this battery has a limited service life, heavy, and expensive. FYI, the production of li-ion battery requires a vast amount of energy and raw materials. And, it’s hard to dismantle into its components again—a problem that is currently bothering the EV industry.
Lithium-sulfur batteries should tackle all the problematic features of the lithium-ion ones. The scientists team claimed that producing the former type of battery has a different method, which is a water-based process.
“This approach not only favors high-performance metrics and long cycle life, but is also simple and extremely low-cost to manufacture, using water-based processes, and can lead to significant reductions in environmentally hazardous waste,” said study co-author Matthew Hill.
One solution to make batteries more eco friendly is recycling. As mentioned before, lithium-ion batteries have a limited service life and once they’re not usable anymore, some of them could end up in landfills, which is bad. What about power cells used in electric vehicles? They’re the same. In fact, recycling is a way to make EVs more sustainable.
As an alternative to making a new type of battery, German startup Duessenfeld is trying to make those lithium-ion batteries more sustainable. “We can reduce the carbon footprint of the battery by 40% and regain over 90% of the materials of a battery cell,” said the CEO, Christian Hanisch.
The Braunschweig-based startup has already recycled batteries for companies with headquarters in the United States. Their mid-term goal is to build a network of decentralized recycling facilities in the U.S. Also, they’re currently looking for financing partners in the United States to set up its own hydrometallurgical plant.
Hanisch explained, “The Duesenfeld process focuses on recycling as much reusable material as possible while bringing down energy consumption and emissions at the same time. The long-term goal is to help companies in the U.S. to improve the environmental balance of their batteries and to keep the raw materials used for their products in circulation.”
What is the recycling process like? First of all, they discharge lithium-ion batteries and shred them under nitrogen, evaporating and condensing the electrolyte. Then, they separate the dry materials according to physical properties such as size, weight, magnetism and electric conductivity (you might get a clearer picture by watching the video).
“We avoid incineration processes to save the electrolyte and graphite from their transformation into carbon dioxide and to avoid smelting of aluminum,” said Hanisch. “This process enables us to regain not only cobalt, copper and nickel, but also the electrolyte, lithium, manganese, aluminum and graphite.”
Duesenfeld has spent 10 years developing its recycling process. At the onset, some 30 researchers and engineers worked for five years on the basics—on three different research projects, which were funded by the German Ministry of the Environment.
(Note: this video is unrelated to the ACS meeting, but the spirit is similar, and I couldn’t find pics or vids about the Fall 2019 expo. Sorry!)
Other than producing lithium-sulfur batteries and recycling lithium-ion power cells, what else are the alternatives? Well, the organic kind is definitely in this list. In August 2019, American Chemical Society (ACS), which is the world’s largest scientific society, held their Fall 2019 National Meeting & Exposition. There were more than 9500 presentations on a wide range of science topics, including organic batteries.
According to this society, li-ion batteries can be harmful to the environment, and the cost of recycling them can be higher than manufacturing them from scratch, which results in landfill disposal. And since the safest way of disposing of them is currently nonexistent or super rare, they opined that developing a protein-based, or organic, battery would change this situation.
Researchers built it using electrodes made of composites of carbon black, constructing polypeptides that contain either viologen or 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO). Now, I have no idea of how to translate the process into simple words because there are lots of scientific terms I don’t know about, so forgive me for that.
Tan Nguyen, a Ph.D. student who helped develop the project, said, “The trend in the battery field right now is to look at how the electrons are transported within a polymer network. The beauty of polypeptides is that we can control the chemistry on their side chains in 3D without changing the geometry of the backbone, or the main part of the structure. Then we can systematically examine the effect of changing different aspects of the side chains.”
Nguyen went on, “What we’ve measured so far for the range, the potential window between the two materials, is about 1.5 volts, suitable for low-energy requirement applications, such as biosensors.”
Now, since the researchers haven’t actually created the battery, making organic batteries commercially available is something that won’t happen in the near future. However, the flexibility and variety of structures that proteins can provide promise wide potential for sustainable energy storage that is safer for the environment. Everything has a beginning, right?