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.
Here’s the beauty part. The cells can be recharged by electrolytes carried in the bloodstream. No grid scale storage possibilities here, but a renewable power source for heart pacemakers and other bodily monitors could be the result. Max Shtein, an engineer at the University of Michigan, came up with the idea of packaging the substrates as origami, making it possible to pack more energy into a smaller space.
Ken Catania at Vanderbilt University has spent years studying the biology of the eels. “Volta’s battery was not exactly something you could fit in a cellphone, but over time we have all come to depend on it,” he says. “Maybe history will repeat itself. I’m amazed at how much electric eels have contributed to science,” he adds. “It’s a good lesson in the value of basic science.”
The Glass Battery Moving Toward Production
John Goodenough, the man who invented the lithium ion battery but has never seen a dime from his discovery, was back in the news last spring with an announcement that he and his team at the University of Texas have developed the first working prototype of a true solid state battery, one that uses a special glass as an electrolyte.
Since then, Goodenough has been working at securing patents and working with a number of battery manufacturers to commercialize the technology for transportation and grid storage applications. “We believe our discovery solves many of the problems that are inherent in today’s batteries,” Goodenough said in a statement. “Cost, safety, energy density, rates of charge and discharge and cycle life are critical for battery-driven cars to be more widely adopted.”
“The road from the lab to the factory is a long one,” says Julia Attwood, an analyst at Bloomberg New Energy Finance. “Some technologies encounter significant difficulties when they attempt to scale up. It could be a while before we’re seeing these materials in electric vehicles or stationary storage.” Nonetheless, Honda announced recently that it is conducting research into solid state batteries for its future electric cars. Since Goodenough is the authority on solid state batteries, we can hope that his lifetime of work will be part of the Honda effort.