Analytical Modeling of a Generalized Multi-Cell Lithium-Ion Battery Multimorph Actuator

Abstract Actuators are fundamental components of modern technology. With the proper inclusion of silicon in a composite anode, a lithium-ion battery can be adapted for use as a self-powered actuator. Lithium-ion battery actuators have the potential to yield quieter and self-powered actuation, which can lead to the development and possible revolutionization of modern actuators. This paper further generalizes the analytical modeling of a lithium-ion battery actuator composed of any number of cathode-anode pairs (CAP) or complete lithium-ion battery cells. Relevant applications include actuator cases which require precise, constant, or silent actuation. Some suggested use cases include underwater soft robotics, and rehabilitative equipment such as active compression sleeves or exoskeleton-based robotics. Two distinct cases in the literature, 13- and 33-layers, have predicted the actuator metrics of a lithium-ion battery actuator, such as free deflection and blocked force [1–3]. However, these models were not sufficiently generalized to show these metrics for a battery actuator beyond a 2-CAP or 6-CAP case without explicitly providing parameters for a particular case. This research generalizes the pattern required to generate the parameters of the 13-layer and 33-layer case studies and creates a generalized code to predict the actuator metrics of a lithium-ion battery actuator composed of (NCAP) number of cathode-anode pairs. The improved simulations account for such characteristics and properly visualize the requested battery actuator’s properties. The modeling of multiple case studies will enable further study for maximizing metrics such as free deflection, blocked force (or zero tip deflection), and actuator energy (or the ability to do useful work). MATLAB is used to create an algorithm that can provide the actuator metrics and order for any size matrix of N-CAPs, and subsequently determine the metrics associated with a change in the State of Charge (SOC) of the battery actuator. The developed N-CAP functions in this paper can be used to predict and validate the performance of a lithium-ion battery actuator through modeling of useful actuator metrics.