The research is expected to pave the way for cheaper and safer battery technologies compared to lithium-ion batteries while still theoretically providing equivalent energy output.
A team of scientists from Fudan University, China, has recently successfully developed a calcium-based battery that can be charged and discharged around 700 times at room temperature. This is seen as a cheaper and safer alternative to lithium-ion batteries (or Li-ion), which have been around for more than three decades.
“With a calcium supply that is 2,500 times greater than lithium, the new battery offers a viable option with potentially equivalent energy density,” the research team stated in the journal Nature. “The battery can transform chemical calcium into a sustainable and promising energy storage technology.”
Calcium batteries can be manufactured into flexible fibers for use in advanced wearable device systems. (Photo: Fudan University).
The research is anticipated to open the door for battery technologies that are cheaper and safer than lithium-ion batteries while still providing theoretically equivalent energy output.
Lithium-ion batteries are known for their high energy density – or the ability to store more energy relative to their weight or size. They are also the most widely used batteries globally.
However, ensuring a supply of lithium is crucial for expanding sustainable industries such as renewable energy storage and electric vehicles.
The International Energy Agency (IEA) has forecasted a lithium shortage by 2024 due to rising demand for electric vehicles, alongside the fact that global reserves are being pushed towards depletion. Additionally, lithium extraction is an expensive process.
The research team from Fudan University indicated that among the different types of calcium-based batteries, the calcium-oxygen system of this new technology has the highest theoretical energy density. This is because the battery’s fuel comes from oxygen in the air rather than from materials stored inside the battery.
The new battery technology also addresses one of the inherent drawbacks of previous calcium-oxygen batteries, which is their inability to operate stably at room temperature.
The research team noted that finding an electrolyte – the component in a battery that allows for charging and discharging – that does not cause calcium reactions limiting battery capacity was a significant challenge for researchers.
To overcome this issue, the team at Fudan University developed a liquid electrolyte that can contain both the calcium and oxygen components of the battery. As a result, the rechargeable batteries they produced could offer a cheaper alternative to lithium-based batteries with the potential for wide-ranging applications.
Moreover, after placing the battery components onto fibers, the researchers found that their fiber batteries could operate stably even when bent from 0 to 180 degrees.
“Calcium-oxygen batteries are proposed to operate stably in air and can be manufactured into flexible fibers to create woven batteries for advanced wearable device systems,” the research team stated.
Although the performance and capacity of calcium-oxygen batteries are still limited, the team indicated that future techniques could enhance the operation of the batteries, and their research also opens up more avenues for producing calcium batteries using other materials.
