In the world of commerce, the three most important considerations are the price, the price, and the price. The world is becoming aware of how grid storage can let renewable energy meet the needs of the utility industry not only during windy or sunny conditions, but also during all hours of the day as well. Yet the price of such large installations is still a barrier to mass adoption of the technology.
Most of the batteries available today use lithium ion cells. The technology and manufacturing process is well understood. They have amazingly good response time. But they have a few drawbacks. First, they cost a lot of money. Second, their performance begins to degrade after a certain number of charge/discharge cycles. Third, they require a cooling system, which adds complexity and cost to each installation.
Rsearchers at Stanford University say they may have an answer to all three of those concerns — a new type of battery that uses manganese, hydrogen, and water to store electricity. Now, bear in mind, this discovery has only been shown to work in the laboratory. It won’t be available in the energy storage section of your local Home Depot any time soon. But it offers the promise of cheaper energy storage that will withstand more charge/discharge cycles than lithium ion batteries. And that means a door has opened that could lead to greater use of renewable energy in the future — something the environment desperately needs.
The research was published in the journal Nature Energy on April 30. Yi Cui, a professor of materials science at Stanford and senior author on the paper, says modestly, “What we’ve done is thrown a special salt into water, dropped in an electrode, and created a reversible chemical reaction that stores electrons in the form of hydrogen gas.” The basic component of the water battery is manganese sulfate, a cheap, abundant industrial salt used to make dry cell batteries, fertilizers, paper and other products, according to Stanford.
Based on the expected lifespan of the new battery, Cui estimatest it would cost a penny to store enough electricity to power a 100 watt lightbulb for twelve hours. “We believe this prototype technology will be able to meet Department of Energy goals for utility scale electrical storage practicality,” he says.
The Department of Energy standard for grid-scale storage is the ability to store and discharge at least 20 kilowatts of power over a period of an hour over the course of at least 5,000 charge/discharge cycles and have a useful lifespan of 10 years or more. The target cost the DOE is looking for is $100 per kWh.
Steven Chu, DOE secretary during the Obama administration and a Nobel laureate says, “While the precise materials and design still need development, this prototype demonstrates the type of science and engineering that suggest new ways to achieve low cost, long lasting, utility scale batteries.” Chu is now a professor at Stanford but was not involved in this research program. Other rechargeable battery technologies being considered by researchers today “are easily more than five times of that cost over their life time,” Cui adds.
The Stanford water battery is not quite ready for prime time just yet. The researchers are using platinum as a catalyst, which is expensive, but Cui explains, “We have identified catalysts that could bring us below the $100 per kilowatt-hour DOE target.”
A lot of research and development remains to be done before the Stanford water battery is ready for commercial use. Only a small percentage of breakthroughs in the lab ever make it to actual production.The $100 per kWh price threshold is something every battery researcher is focused on. Even lithium ion batteries may crack that barrier one day. But if the water battery can withstand more charge/discharge cycles, its total overall cost will be lower.
Will the new technology from Yi Cui and his team be one of the ones that makes it out of the lab and into production? “We’ll see,” said the Zen master.