White Graphene Enables Lithium-Ion Batteries Withstand High Temperatures
Composite made with white graphene can enable lithium-ion batteries to withstand high temperatures, a new study has found.
Batteries made with the said composite were found to survive and function efficiently even in temperatures as high as 150 degrees Celsius. These batteries can do so even after more than a month of use, without really sacrificing efficiency.
"We tested our composite against benchmark electrodes and found that the batteries were stable for more than 600 cycles of charge and discharge at high temperatures," says study lead author Marco-Túlio Rodrigues.
The quest for efficient and clean energy source is on the rise. As a result, more novel types of batteries are being invented. One example is Energizer's rechargeable batteries made from recyclable cells — a first in the world. With a commitment to stay eco-friendly, the company was able to prove that it is possible for alkaline batteries to be made up of used materials.
White graphene or hexagonal boron nitride (h-BN) is a vital component of a non-flammable composite. The atom-thin compound is the combined electrolyte and separator for rechargeable batteries that provide energy at functional voltages and at increased temperatures.
h-Bn is not a conductor, much more an ionic conductor. With this, Rodrigues says his team did not expect it to have any form of benefit to batteries. However, materials that are chemically and mechanically resistant, even in the midst of extreme hot temperatures, may somehow provide stability to the electrolyte at some point.
Boron nitride is relatively inert or inactive; therefore, it neither reacts with chemicals nor contract or expand significantly. Add these properties to the ultimate ability to withstand high temperatures and scientists get a perfect product.
The material does not need the help of separators or covering to keep the electrodes of batteries safe from short circuit.
Scientists More Than Pleased With The Results
In 2015, scientists from the Rice and Wayne State University presented an electrolyte than can function at 120 degrees Celsius. The team this year was able to surpass that.
In fact, the results of the testings were much better than expected, the scientists say.
Study co-author Hemtej Gullapalli says it took nearly two years to prove that a compound as simple as boron nitride can provide benefits to battery performance.
Batteries with the electrolyte are driving its way toward industrial and aerospace applications, and not merely on small gadgets such as mobile phones.
The batteries may also help the oil and gas industry by providing strong performance to power sensors on wellheads.
No Issues On Safety
Gullapalli says the electrolyte does not carry any issues when it comes to safety. If there are any failures encountered, it sure would not involve fire.
At present, there are no batteries that can withstand 80 degrees Celsius, commercially available in the market. The authors would like to eventually change that and produce stable batteries that can work at twice this temperature or even more.
The study was published in Advanced Energy Materials on April 9.