Researchers at the Rensselaer Polytechnic Institute developed a novel type of nanomaterial that can make power packs for future electric vehicles sturdier and more durable than today’s lithium-ion batteries.
Called nanoscoop, the new material is designed to endure extremely high rates of charge and discharge that would otherwise weaken and damage current lithium-ion batteries.
A nanoscoop electrode can be recharged and discharged at a rate 40 times to 60 times faster than current battery anode technologies, while maintaining the same energy density, explained Nikhil Koratkar, lead researcher of the project.
The conventional anode structure of a lithium-ion battery expands when the battery charges and contracts when it discharges, as lithium-ions flow into or escape from the anode, respectively, during charging periods.
These alterations in volume build up stress in the anode, and this might result in premature battery failure if stress builds up too quickly during fast charging periods. Thus, current batteries for cell phones and laptops are designed to charge very slowly.
However, the nanoscoop is engineered to withstand this buildup of stress. The material is composed of a carbon nanorod base, which is crowned with a thin coating of nanoscale aluminum and a scoop of nanoscale silicon.
The structures are flexible and able to quickly accept and discharge lithium-ions at extremely rapid paces without sustaining significant damage. The multilayer design minimizes the stress caused by quick charging, allowing the electrode to maintain its original structure.
“Due to their nanoscale size, our nanoscoops can soak and release lithium-ions at high rates far more effectively than the macroscale anodes used in today’s lithium ion batteries,” said Mr. Koratkar.
“This means our nanoscoop may be the solution to a critical problem facing auto companies and other battery manufacturers – how can you increase the power density of a battery while still keeping the energy density high?,” he added.
Currently, all-electric vehicles are equipped with two different battery technologies – supercapacitors and conventional lithium-ion batteries. Supercapacitors are used for power-intensive tasks such as vehicle startup and rapid acceleration, while conventional batteries are used for cruise driving and other operations.
According to Mr. Koratkar, nanoscoop technology can combine these two separate systems into a single, more efficient battery unit.
