Soft ionic materials combine charged mobile species and tailored polymer structures in a manner that enables a wide array of functional devices. Ionic devices hold the promise of using the wide range of chemical and molecular properties of mobile ions and polymer functional groups to enable flexible conductors, deformable digital or analog signal processors, which have emerged as promising candidates for various applications in energy storage, electronic sensing, and biomedical devices. Central to their functionality is the intricate ion transport mechanism that governs the movement of charged species within their structures. This thesis delves into the fundamental understanding of ion transport mechanisms in ionic devices, unraveling the intricacies from a molecular level. Molecular dynamics simulations are employed to investigate the behavior of ions within two ionic devices, metal-ligand coordinated polymeric conductors and polyelectrolyte diodes, shedding light on the factors influencing their mobility and diffusion such as clustering, hopping or water content. By bridging the gap between theoretical insights and experimental observations, this work provides a molecular level understanding on the underlying ion transport mechanism and the relationship between the device performance. Keywords: ion transport, ionic devices, molecular dynamics, ionic clustering, ionic conductivity, rectification effect