Creating domestically made electric car batteries that allow for quick charging and long-range performance is essential to boosting the competitiveness of the US transportation sector. However, charging speeds and battery life may suffer as a result of the energy density required to increase driving distance.
Researchers at the Department of Energy’s Oak Ridge National Laboratory have shown how to produce a battery with exceptional energy density and a long-lasting capacity to withstand extremely rapid charging by including a novel kind of current collector, a crucial battery component. This makes it possible to recover at least 80% of the battery’s energy in ten minutes. Additionally, the technique eases pressure on U.S. supply chains by utilising less metal, especially copper, which is in high demand.
Because far less copper and aluminium are required, this results in huge savings on near-critical materials, according to principal researcher Georgios Polyzos. “This will also significantly increase the energy density that can be achieved with a 10-minute charge.”
Electricity is transferred from the battery’s active component to an external circuit via a current collector. Metal foil is typically used to create current collectors, one for each electrode pole: one for the cathode and one for the anode. The metals make the battery heavier, which raises the car’s total weight and the energy needed to propel it.
The industrial partner Soteria Battery Innovation Group created the innovative current collector, which consists of a polymer encased in extremely thin copper or aluminium layers. Even under extremely high charging temperatures that can cause battery materials to deteriorate more quickly over time, ORNL researchers discovered that this innovative component can save current collector costs by 85%, pack in 27% more energy for longer trips, and maintain a considerable energy density after a thousand cycles. With around a fourth of the weight, the new current collector performs as well as its traditional version, allowing an EV to go farther on a single charge.
At ORNL’s open-access Battery Manufacturing Facility, researchers used industry-standard procedures to create coin and pouch cell batteries, ensuring the technology could be scaled up for commercialisation.
Even though the thinner material is more likely to wrinkle, Polyzos said the team was able to identify the right parameters for successfully integrating it into the roll-to-roll production process. Standard roll-to-roll techniques are incompatible with the costly and intricate manufacturing processes needed for other experimental current collectors.
The metal-polymer current collector has the potential to “revolutionise the roll-to-roll battery manufacturing process and significantly advance the performance metrics of lithium-ion batteries in electric vehicle applications,” according to ORNL’s study results, which were published in Energy & Environmental Materials.
Despite the plastic film’s higher physical resistance, Brian Morin, CEO of Soteria, a firm based in South Carolina, said ORNL has helped the company understand how to achieve rapid battery charging using the technology.
“We remove 80% of the metal, which makes it more difficult to complete tasks quickly,” Morin stated. However, they have demonstrated that rapid charging and discharging are still possible. According to Soteria’s testing, the polymer also increases battery safety. The plastic film is eaten by an internal short circuit that creates a momentary energy surge, which causes the metal to come loose. About 90% of lithium-ion battery fires brought on by short circuits are prevented by our current collector, which functions inside the battery like a circuit breaker.
DOE’s Advanced Materials and Manufacturing Technologies Office, or AMMTO, provided funding for the study of metallised polymer current collectors. Jaswinder Sharma, Wheatley Steenman, Sabine Neumayer, and Sergiy Kalnaus are among the other ORNL researchers working on the project.
For the Department of Energy’s Office of Science, the biggest funder of fundamental physical science research in the US, UT-Battelle oversees ORNL. Some of the most important issues of our day are being tackled by the Office of Science.