An Innovative Low-Cost Battery Design Made of Cheap, Common Materials
Researchers have created a brand-new type of battery that could serve as low-cost backup storage for renewable energy sources like wind and solar. This battery is made entirely of accessible and affordable materials. An affordable, readily available battery comprised of aluminum and sulfur could offer backup storage for renewable energy sources.
The need for affordable, large-scale backup systems to provide electricity when the air is calm and the sun is down is increasing quickly as increasingly greater installations of wind and solar power systems are erected across the world. For the majority of these uses, lithium-ion batteries still cost too much today. Other options, such as pumped hydro, need a certain topography that isn’t always present.
Researchers from MIT and other institutions have created a brand-new type of battery that could help close that gap. It is constructed entirely from readily available and affordable components.
Today, on August 25, 2022, the magazine Nature published a description of the novel battery architecture, which uses molten salt electrolyte sandwiched between two electrode materials of aluminum and sulfur. Professor Donald Sadoway of MIT and 15 other authors from MIT, as well as China, Canada, Kentucky, and Tennessee, collaborated on the paper.
In addition to being
An Innovative Low-Cost Battery Design Made of Cheap, Common Materials , lithium-ion batteries have a flammable electrolyte, which makes them unsuitable for shipping. Sadoway therefore began exploring the periodic table for inexpensive, readily available metals that could possibly take the place of lithium. He claims that iron, the most popular metal in commerce, lacks the proper electrochemical characteristics for an effective battery. Aluminum, on the other hand, is the second-most plentiful metal on the market and the most abundant metal overall. “So, I decided that we should just use that as a bookend.
The next step was choosing the other electrode to go with the aluminum and the electrolyte that would go between them to transport ions back and forth during charging and discharging. The volatile, flammable organic chemicals that have occasionally resulted in dangerous fires in cars and other applications of lithium-ion batteries were not going to be used as the electrolyte, according to Sadoway. As opposed to many salts’ melting points, which can reach around 1,000 degrees Fahrenheit (538 degrees Celsius), many molten salts have comparatively low melting temperatures that are close to the boiling point of water.
In their tests
An Innovative Low-Cost Battery Design Made of Cheap, Common Materials , the scientists demonstrated that the battery cells could operate at extraordinarily high charging rates for hundreds of cycles with a predicted cost per cell that was roughly one-sixth that of comparable lithium-ion cells. They demonstrated how the working temperature had a significant impact on the charging rate, with 110 °C (230 °F) demonstrating 25 times faster charging rates than 25 °C (77 °F).
Unexpectedly, the team’s decision to employ molten salt as an electrolyte simply because of its low melting point ended up having an unexpected benefit. The growth of dendrites—narrow metal spikes that develop on one electrode and eventually spread across to make contact with the other electrode, short-circuiting the battery and impairing efficiency—is one of the main issues with battery reliability. However, it so happens that this specific salt is excellent at avoiding such an issue.
The salt they used, chloro-aluminate, “basically decommissioned these runaway dendrites while also allowing for very quick charging,” according to Sadoway. We conducted studies with very fast charging times—less than a minute—and we never had cell loss owing to dendritic shorting.
Additionally, the battery doesn’t need an outside heat source to stay at its operational temperature. “The charging and discharging of the battery naturally generates heat through electrochemistry. Then, when you discharge it, it also produces heat, according to Sadoway. For instance, in a typical load-leveling arrangement at a solar power plant, “you would store electricity when the sun is shining, and then you would draw electricity after dark, and you would do this every day. And that cycle of charge-idle-discharge-idle produces enough heat to maintain the object’s temperature.
Other technologies, such as the liquid metal batteries Sadoway and his students developed several years ago and which served as the foundation for a spinoff company called Ambri, which hopes to deliver its first products within the next year, may be more effective for larger installations, up to utility scale of tens to hundreds of megawatt hours. Sadoway recently received the 2018 European Inventor Award for that creation.
According to Sadoway, the aluminum-sulfur batteries’ lower size would also make them useful for applications like electric vehicle charging stations. In his words, “if you try to do that with batteries and you want rapid charging, the amps are just so high that we don’t have that amount of amperage in the line that feeds the facility.” As is the case today with gasoline fuel pumps, “the amperages are just so high that we don’t have that amount of amperage in the line that feeds the facility.” So it may not be necessary to create pricey new power lines to supply these chargers if a battery system like this can store energy and swiftly release it when needed.
Avanti has leased the patents to the system. According to Sadoway, “the first item of business for the company is to demonstrate that it works at scale” before putting it through a number of stress tests, such as doing hundreds of charging cycles.
Would a sulfur-based battery be susceptible to emitting the unpleasant smells connected to various kinds of sulfur? “No chance,” says Sadoway. “The gas, hydrogen sulfide, has a rotten-egg odor.