Persistent luminescence nanomaterials with up-/down-conversion modes for power battery temperature measurement

With the development of new energy vehicles, the safety concern of power batteries has become urgent, making the exploitation of new temperature sensors for the batteries important. In this paper, persistent luminescence nanoparticles (PLNPs) of Bi 1.91 Ga 4 O 9 : 0.04 Er 3 + , 0.05 Eu 3+ with up- and down-conversion luminescence were prepared by a simple and low-cost co-precipitation method. Single rare earth element doping of Er 3+ achieves up-conversion luminescence at 526 nm/550 nm under 980 nm excitation. After co-doping with rare earth element Eu 3+ , it can realize the down-conversion luminescence at 590 nm/614 nm under 254 nm excitation. They showed obvious temperature dependence at 293–503 K and 423–573 K, respectively. The corresponding maximum relative sensitivities are 0.98 % K −1 and 0.55 % K −1 . Interestingly, all temperature ranges cover the spontaneous ignition point of the power battery at 473 K. Thus, the PLNPs-based sensor was successfully validated for monitoring overheating and spontaneous combustion of power battery with the dual-channel temperature measurement modes. The two kinds of temperatures were verified with each other for the improved sensitivity and accuracy, so they were used to accurately measure the temperature of the power battery in real time for early warning and the improved safety. Thus, we provided a new application scenarios of PLNPs in the field of temperature sensing for monitoring the temperature of battery.