Synthesis of hybrid polymer/liquid electrolytes for lithium-ion batteries

In recent years, due to the increased sensitivity towards the theme of sustainability, lithium-ion batteries have grown interest as well-established potential solutions for replacing fossil fuels. For this reason, different ways to optimize battery technologies have been covered. One idea is based on the concept of massless energy storage and is represented in practice by structural lithium-ion batteries, multifunctional systems that provide satisfying electrochemical and thermomechanical properties at the same time. The basic components of batteries have been redesigned. Electrodes made of carbon fibres are now at an advanced stage of research, while the electrolyte has not been optimized yet. Bicontinuous electrolytes have been obtained through polymerization-induced phase separation to ensure appreciable ionic conductivity and stiffness, thanks to the cooperative work of the polymer network and the liquid percolating phase. Reaction kinetics, thermodynamic of mixing and physical properties have been related to each other to define whether it is possible to predict the morphology of the electrolyte, which is responsible for providing the required properties. Even though the mechanisms are complex, and the intervening variables are interconnected, relevant conclusions can be presented. Particularly, it is underlined the synergetic effect of the constituting monomers in copolymers in enhancing ionic conductivity. Moreover, a gradual transition between percolating structures and gels was experienced, suggesting that mixed bicontinuous-gel structures could be explored as potential solutions for certain applications. The present research aims to provide understanding for further studies in the field.