Magnetism Versus LiFePO4 Battery’s State of Charge: A Feasibility Study for Magnetic-Based Charge Monitoring.

In recent years, lithium ion batteries have become wide-spread energy sources for various battery-powered applications. In particular, LiFePO4 batteries are increasingly used for high-power automotive and storage applications. Unfortunately, the state of charge (SOC) is not uniquely determined by measuring just the LiFePO4 battery’s open-circuit voltage. However, an alternative approach for SOC determination is introduced by investigating the battery’s magnetic susceptibility. This is motivated by the iron atom’s magnetic state in the LiFePO4 cathode material, which changes during charging and discharging. The magnetic susceptibility of differently charged battery samples will be investigated to correlate the magnetic moment with the SOC in view of a new sensor concept. [ABSTRACT FROM PUBLISHER]