A breakthrough study featured in ACS Energy Letters sheds light on the challenges faced by lithium-ion batteries (LiBs) powering drones during high-stress events like takeoff. The research team, led by Ilias Belharouak and Marm Dixit, developed a cutting-edge electrolyte to enhance LiB stability, presenting a potential solution for the longevity issues associated with these power cells.
Lithium-ion batteries, renowned for their compact size and high energy density, have become a staple in various applications, including powering drones. However, the strain placed on LiBs during rapid power draw, such as vertical takeoff, can significantly impact their performance and lifespan. To delve into this issue, the researchers subjected a set of LiB cells to extreme stress by draining 15 times their optimal capacity for 45 seconds, simulating the demands of a vertical takeoff.
The results revealed that under high-stress conditions, none of the tested cells lasted more than 100 cycles, with performance decline evident around 85 cycles. Following this “stress test,” the researchers explored the potential for retired LiBs in less strenuous applications. When subjected to a more normal, lower rate power draw, the cells partially retained their capacities, suggesting a second life for these stressed batteries in applications with typical power demands, such as battery backups for power supplies and energy-grid storage.
Despite the promising findings, the researchers focused attention on the need for further development in alternative battery technologies suited for high-stress applications like vertical takeoff.
This groundbreaking research, conducted at Oak Ridge National Laboratory with funding from the U.S. Army Combat Capabilities Development Command (DEVCOM) Army Research Laboratory, opens new perspectives for enhancing the efficiency of lithium-ion batteries in aerial electric vehicles.
