A compliant and low-expansion 2-phase micro-architectured material, with potential application to solid-state Li-ion batteries

Abstract

A two-phase 2D lattice material is identified that possesses both a high macroscopic compliance and a low macroscopic coefficient of thermal expansion. The macroscopic effective properties of the lattice are analysed and the features that give high macroscopic compliance and low macroscopic actuation strain are identified. A detailed case study is presented to explore the potential of the lattice for use as a composite cathode in a solid-state Li-ion battery, taking into account the swelling of the active cathode material upon lithiation. A design map is developed to reveal the competition between battery capacity and degradation due to fracture of the composite cathode. The intent is to identify promising battery topologies and compositions by overcoming the usual problems associated with cathode swell during charge and discharge.