We live in a world where energy is currency. Wars are fought over petrol and other fossil fuels, whilst millions of people work tirelessly to provide alternatives like solar energy to prevent global warming and provide a greener and safer future for our planet.
Since energy is so important, a lot of research is put into it, yielding fascinating results. The most recent one has to do with lithium-sulfur batteries. Their mechanism is not new; in fact, it has been known for decades. But there have always been practical imperfections with their functioning. Scientists seem to have discovered a way to solve them and create one of the most useful batteries to date.
Normally, this battery consists of two electrodes, one made of lithium and the other of a carbon-sulfur compound. When the battery works, ions from one electrode move to the other through the electrolyte, creating a current. Unfortunately, lithium can react with the sulfur and form lithium sulphides, which dissolve into the electrolyte and slowly use up the sulfur electrode. Up until now, the solution had been to add some other chemicals, like titanium oxide or manganese dioxide, which would stabilise the sulfur and prevent it from dissolving so easily in the electrolyte. But the method which seems the most promising is actually the most unexpected: adding DNA.
Yes, you read that right. DNA, deoxyribonucleic acid, the organic molecule that codes for all of our characteristics actually improves lithium-sulfur batteries. DNA is made of oxygen, nitrogen and phosphorus, and luckily for material scientists, all these elements easily bond with sulfur. This makes DNA ideal for trapping sulfides, preventing them from dissolving in the electrolyte. In turn, it improves the efficiency of these batteries by almost 3 times. Even better: DNA is cheap and biodegradable, and a very small amount is needed for it to improve the battery’s performance.
The interest in this specific type of batteries is not unjustified. They have a high energy density (can deliver up to 3 times as much energy as lithium ion cells), are cheaper to produce and greener for the environment. It is therefore not strange that scientists are trying to do as much work as possible to help improve this technology. However, the battery world is a slow one, and although an idea may look good in the lab, it is harder to extrapolate that into the industry. But keep your hopes up! Lithium-sulfur batteries could very well substitute the widely used lithium ion cells in only 15 years, with original ideas like the one exposed on this article to push it through.