Using a magnetic material can help monitor the remaining life of a rechargeable battery to determine when it needs to be recharged, a new study shows. The study was led by Shenqiang Ren, a researcher at the University at Buffalo.

The researchers explain how the system works: When a lithium-ion battery is charged and discharged, lithium ions flow from one side of the battery to the other. With this in mind, the team constructed a lithium-ion battery that uses a special material at one end. The magnetic properties of the compound change when lithium ions enter or leave. Therefore, by tracking the magnetic changes of the material, the charge of the battery can be measured.

"The main goal of this project is to study magneto-ionics, which uses ions to control the magnetic properties of a material," Ren said. "As lithium ions move in and out of a material, the magnetization of the material changes. By monitoring the magnetic field, lithium ions can be monitored indirectly. The researchers believe that with this method, the state of charge can be sensed precisely, quickly, and sensitively." Ren is a professor of mechanical and aerospace engineering and a professor of chemistry at the University at Buffalo and the RENEW Institute at the University at Buffalo. core faculty.

This magnetic ionic material is made of vanadium, chromium and cyanide with water ligands. The properties of this compound make it an ideal material for rechargeable batteries. With related technologies, changes in the magnetic properties of materials in rechargeable lithium-ion batteries can be measured.