Bidirectional Correlation between Mechanics and Electrochemistry of Poly(vinyl alcohol)-Based Gel Polymer Electrolytes.

ABSTRACT

The electrochemical-mechanical coupling property of solid electrolyte membranes is critical to improving the performance of solid-state energy storage devices. A new phenomenon was observed in which the electrochemical charge-discharge process induced aligned wrinkles on the edge of poly(vinyl alcohol)-H2SO4 gel polymer electrolytes (GPEs), which is attributed to the deformation of polymer chains under electrochemical stimulation according to multiscale simulations. In the reverse direction, by means of modeling and testing, it was proved that the ionic conductivity of GPEs can be tuned by mediating the mechanical properties of GPEs via tailoring the polymer at the nanoscale. This bidirectional correlation reveals the coupling mechanisms between mechanical and electrochemical properties of GPEs and provides an insightful understanding of the origin and regulation of the ionic conductivity of GPEs, which is fundamental to improving the performance of GPEs.