Characterization and Model of Piezoelectrochemical Energy Harvesting Using Lithium ion Batteries

Abstract

Although lithium ion battery research often focuseson electrochemical properties, lithium ion intercalation mate-rials are also mechanically active. Essentially, these materialsexhibit a mechanical-electrochemical coupling such that whena stress is applied, the voltage of the battery increases. In thiswork, we develop a model to study and predict the effective-ness of intercalation materials as mechanical energy har-vesters. Specifically, we show that a lithium ion battery har-vester can be modelled as a simple circuit and that we canmake both qualitative and quantitative predictions about theeffectiveness of a battery material given its intrinsic mechan-ical and electrochemical properties. The measured efficiencyof our system, calculated from the energy output and totalwork input, is 0.012 ± 0.004%, and our model predicts thatthe maximum theoretical efficiency of the system is2.9 ± 0.5%. In the future, this model will help us developand study other intercalation materials that will bring the mea-sured efficiency closer to our proposed theoretical maximum.