Stanford Scientists Close in on Cheap Solar Storage with New Battery
A new battery could help make using renewable energy sources much less expensive. Stanford University chemistry professor Hongjie Dai and Michael Angell, a doctoral candidate, developed the battery to store power generated by resources like wind turbines and solar panels.
Two years ago, the Stanford team debuted the first ever “high-performance” aluminum-ion battery, billed as a cheaper alternative to lithium batteries. But the aluminum battery’s electrolyte (the medium that connects a battery’s two terminals) was still relatively expensive, and since then, Dai and Angell have been looking for a commonly available material to replace it. In promising new research, they seem to have found a solution in urea—a chemical compound found in sweat and urine, and often used in agricultural products—creating a battery that is, according to Dai, about 100 times cheaper than its predecessor.
“Urea makes for a good electrolyte mainly because it is so cheap,” wrote Dai in an email. “It is currently manufactured [in quantities of] more than 180 million tons yearly for use in fertilizers.”
That humble chemical compound could make Dai's new battery just what the renewable energy sector needs right now.
In 2016, solar panels became the biggest source of new energy capacity in the U.S., beating out growth from fossil fuels and wind power for the first time, according to Bloomberg. But despite the growing enthusiasm for solar, there are still a few hurdles keeping the technology from reaching its potential—in particular, storage has been a difficult issue to overcome.
Here’s the problem: the amount of available sunshine varies between different seasons and times of day. So if you want the lights on at night, you need to stash energy generated during brighter hours. (Wind power, dependent on weather conditions, faces similar challenges.) But existing storage batteries are expensive and inefficient, and often contain flammable or toxic materials. Though new concepts are always popping up, nothing has definitively proven scalable or cost-effective enough to really encourage the large-scale viability of renewable energy.
Speaking to Stanford News Service earlier this month, Dai said “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.” He believes it’s feasible that his team’s research could provide a way for electrical companies and municipalities to better stow renewable energy and distribute it to consumers. “Grid scale storage is an appropriate goal for this battery,” he wrote in his email.
When it comes to supporting the electric grid, Dai points out, the new battery has a few advantages over other inexpensive storage solutions. For example, “Our battery's cycle life should … outperform lead-acid [batteries],” he wrote, referring to one of the oldest and most common types of batteries. (Cycle life measures the number of times a battery can be charged before its capacity for storing energy begins to drop.) This staying power is important because, as Brian Warshay, an analyst at Bloomberg New Energy Finance, told NPR last year, "Typical grid infrastructure, what utilities tend to invest in, are equipment and projects that last decades."
Additionally, Dai says his team’s research has created a product that is safer than alternatives: It “presents a negligible toxicity hazard, which is not the case when using lead, which requires special care for disposal,” he wrote. The new battery is also nonflammable, unlike lithium-ion batteries, which can occasionally overheat and explode. (The public learned this most recently with the recall of Samsung’s Galaxy Note7 phone, which contained a faulty battery prone to catching fire.)
According to Stanford News Service, Dai has already received commercial interest in the aluminum-ion battery. To that end, he’s started a business, a VC-funded startup called AB Systems, which is licensing the research from Stanford in the hopes of bringing the new battery to market.
The Stanford team’s research and findings were published in journal Proceedings of the National Academy of Sciences in January.