Electrolytes are a fundamental component of many electrochemical devices, such as batteries and electrolyzers, which have promising applications in sustainable energy and decarbonization. In these devices, the electrolyte plays a crucial role in transporting ionic species across the cell while resisting degradation under harsh electrochemical conditions. Conventional Li-ion batteries use liquid organic electrolytes, which can offer fast ion transport but present safety hazards as they are flammable, volatile, and toxic. Polymer-based electrolytes are a promising alternative that provide high safety and electrochemical stability, but cell performance is limited by slow diffusion through these materials. Tuning the structure and composition of polymer electrolytes is required to optimize their ionic conductivity. A promising approach to achieving improved ionic conductivity is adding a liquid solvent to a solid polymer matrix, to form a gel polymer electrolyte. This work has used molecular dynamics (MD) simulations to study a series of gel polymer electrolytes for Magnesium Ion Batteries. The simulation results revealed how varying the composition by changing the anion or solvent affects the molecular structure of the material. Non-equilibrium molecular dynamics (NEMD) simulations have also been used to evaluate electrolyte transport properties, such as ionic conductivity. These computational methods were found to be broadly effective for studying structure and transport relationships in materials for electrochemical devices.1