Probing Mechanical Properties: Tools for Investigating Solid Polymer Electrolytes

Lithium-ion batteries (LIBs) have become an essential energy storage technology for a variety of applications, such as energy storage systems, electric vehicles, and flexible electronics. However, due to safety concerns regarding the flammability of the liquid electrolytes used in conventional LIBs, their use has been restricted; thus, there is considerable interest in the use of solid polymer electrolytes (SPEs) and other solid electrolytes. These SPEs inhibit the growth of lithium dendrites and prevent thermal runaway, which is responsible for the instability of liquid electrolytes. Despite this, SPEs have inferior mechanical properties, resulting in a reduced battery cycle life. Thus, SPEs have been modified by incorporating particles, particularly nanoparticles, into their polymer matrix in order to improve their mechanical properties. Due to their inherent properties, including a large surface area and mechanical rigidity, these nanoparticles improve the interfacial contact and electrochemical stability of these modified SPEs. Consequently, it is essential to investigate the mechanical properties of these SPEs using appropriate techniques. Even though numerous reports have investigated the mechanical properties of some of these SPEs, there is insufficient literature on the tools/techniques for analyzing these mechanical properties. In this review, the experimental techniques used to explore the mechanical properties of SPEs are described.