Lithium-ion battery cathode and anode potential observer based on reduced-order electrochemical single particle model

•Reduce order and linearise the electrochemical model of Li-ion cells.•Design an anode potential observer based on linearised reduced order SPMe model.•Predict cathode and anode potential of Li-ion cell during charging and discharging.•The model and observer are verified with data from a three-electrode experiment.•The designed observer has less computational load and acceptable accuracy.