Magnetism vs. LiFePO4 battery's state of charge: A route to a novel sensor concept

In recent years, LiFePO
4
has become a versatile cathode active material for rechargeable batteries. Unfortunately, the control of the battery's state of charge is not uniquely determined by measuring just the LiFePO
4
battery's open circuit voltage. For this reason, an alternative way of state of charge control is introduced by investigating the battery's magnetic susceptibility. This is motivated by the change of the iron atoms's magnetic state in the LiFePO
4
cathode material during charging and discharging. The magnetic susceptibility of differently oxidized LiFePO
4
samples will be investigated in order to correlate the magnetic sensitivity with the SOC in view of a new sensor concept.