We study the mechanical behavior of rechargeable batteries in the context of optimization as either solid-state actuators or as long- life electrochemical energy storage devices.

Electrically operated actuators can have applications from robotics to morphing structures. Compared to state of the art actuators such as piezoelectrics, dielectric elastomers, shape memory materials, and ionomer polymer metal composites, electrochemical actuators possess a unique combination of low voltage actuation, “set and forget” capability, large strain (capable of > 100%), and large stress (capable of > 1 GPa). We have previously shown the feasibility of using a battery as an actuator. Initial work with graphite intercalation compounds generated actuators with energy densities on the order of 1 MJ/m3 that rival those of NiTi shape memory alloys. We then extended this concept to electroplating of metals as an actuation mechanism. Our current interest is to greatly expand the chemistry and device architecture choices of electrochemical actuation to achieve unprecedented energy density that can enable a broad range of applications.

A solid-state lithium battery can act as a high-energy density actuator.
 
Reference: Solid-state actuation based on reversible Li electroplating, William Barvosa-Carter, Cameron G. Massey, Geoffrey McKnight, Ping Liu, Smart Structures and Materials 2005: Active Materials: Behavior and Mechanics, edited by William D. Armstrong, Proceedings of SPIE Vol. 5761, p. 90