Sensorless Temperature Estimation of Lithium-Ion Battery Based on Broadband Impedance Measurements

Temperature monitoring is of paramount importance for guaranteeing the safety and proper operation of lithium-ion batteries. Traditional temperature sensors suffer from heat transfer delay, where internal battery temperature cannot be measured directly. Motivated by this, this letter proposes a novel sensorless temperature estimation method based on broadband impedance spectroscopy. In this letter, pseudorandom sequence (PRS) with finite signal levels is utilized for impedance measurements. The measured impedance information is merged into an impedance-temperature model, which cooperates with a specially designed least-square method for temperature estimation. The proposed framework is robust against interference, whereas simple enough for online implementation. Experimental results suggest excellent estimation accuracy of the proposed method under different circumstances.