Pvdf Based Gel Polymer Electrolyte for Applications in Flexible Devices

In the last years growing interest is being focused on the production of flexible devices including electronics, organic solar cells and displays. Considering specific applications where electrochemical processes take place, e.g. Die Sensitized Solar Cells (DSSC), an electrolyte is needed between the electrodes to allow ion diffusion and redox reactions.  In this case, relevant issues are related to the fluid, namely liquid, nature of traditional electrolytes. Considering this characteristic, the limitation is twofold: on one hand, considering large area devices, for example DSSC integrated in the façade of buildings, electrolyte flow from the top to the bottom of the system can occur. On the other hand electrolyte leakage may occur in the presence of defects or damage, with significant environmental safety concerns. Finally, considering flexible devices, issues are relative to electrolyte flow during bending, due to pressure gradients inside the device. It’s therefore clear that most of these limitations could be overcome using electrolytes with good ion transport properties but also higher resistance to flow with respect to traditional systems, i.e. electrolytes behaving as much as solids when subjected to external loads/strains. For this reason a process is proposed that allows producing a PVdF network by sol-gel method, this is soaked with electrolyte and allows maintaining good ion conductivity and excellent transparency while highly reducing issues related to leakage and electrolyte flow inside between the electrodes of the device.