Battery Researchers Keep Coming Up With New Breakthroughs
Batteries are the key to the zero carbon future, there’s little argument about that. But today’s batteries are less than ideal in many respects. They cost too much, are too big, weigh too much, function poorly in low temperatures, are prone to catch fire under certain circumstances, or simply don’t last long enough. Battery researchers at dozens if not hundreds of labs around the world are seeking answers to all those concerns. Here are four new developments that hold promise, according to Renewable Energy World.
The Urea Battery
At Stanford University, Professor Hongjie Dai and doctoral candidate Michael Angell have come up with a new battery that solves two of the principal objections to today’s standard lithium ion batteries — cost and flammability. Their battery is nonflammable because its uses urea — found in the urine of mammals and a common ingredient in fertilizers — as the electrolyte. For electrodes, it uses aluminum and graphite, both of which are abundant in nature and far less costly than the lithium, cobalt, and graphene commonly used in batteries today.
“So essentially, what you have is a battery made with some of the cheapest and most abundant materials you can find on Earth. And it actually has good performance,” says Dai. “Who would have thought you could take graphite, aluminum, urea, and actually make a battery that can cycle for a pretty long time?” He created one of the first aluminum batteries in 2015, but the electrolyte was far too expensive for commercial use. The urea electrolyte is 100 times less expensive, is more efficient, and can be fully charged in just 45 minutes. The new research has been published in the Proceedings of the National Academy of Sciences.
Angell says the aluminum battery is being developed primarily for grid scale energy storage. “It’s cheap. It’s efficient. Grid storage is the main goal,” he says. The new battery has a highi Coulombic efficiency of 99.7%. Coulombic efficiency is a measure of how much charge exits the battery per unit of charge taken in during charging.
“I would feel safe if my backup battery in my house is made of urea with little chance of causing fire,” Dai says. “With this battery, the dream is for solar energy to be stored in every building and every home. Maybe it will change everyday life. We don’t know.” The research, which is supported by the US Department of Energy, The Global Networking Talent 3.0 Plan, the Ministry of Education of Taiwan, and the Taishan Scholar Project, is ongoing.
The Hydronium Battery
Graduate student Xingfeng Wang and his colleagues at Oregon State University report they have developed a new type of battery that uses hydronium ions to carry an electrical charge between its electrodes. Hydronium is a water molecule with an added hydrogen ion. In a study published in the journal Angewandte Chemie International Edition, a publication of the German Chemical Society, the scientists say they have demonstrated that hydronium ions can be reversibly stored in an electrode material consisting of perylenetetracarboxylic dianhydridem, or PTCDA. Their battery uses dilute sulfuric acid as the electrolyte.
“This may provide a paradigm shifting opportunity for more sustainable batteries,” says Xiulei Ji, assistant professor of chemistry at Oregon State and the corresponding author on the research. “It doesn’t use lithium or sodium or potassium to carry the charge, and just uses acid as the electrolyte. There’s a huge natural abundance of acid, so it’s highly renewable and sustainable.” Dilute sulfuric acid is what conventional lead acid batteries use.
A Flexible Organic Battery
A team of researchers led by Michael Mayer at the University of Fribourg have developed a new soft battery that takes its inspiration from nature — the electric eel, in particular. Alessandro Volta did the first pioneering research on eels two centuries ago and created the first synthetic battery — a long stack of zinc and copper discs, separated by salt-soaked cardboard. An article in the The Atlantic explains that scientists have returned to those first principles to arrange a series of organic chemicals in rows on two substrates. Pushing them together creates a small voltage at each point of contact but they can combine to provide up to 110 volts of electricity.