Effect of Electrolyte\nComposition on Biphasic Structural\nElectrolytes for Laminated Structural Batteries

Bicontinuous solid–liquid electrolytes can combine\nhigh\nionic conduction with high mechanical performance and provide an opportunity\nto realize laminated structural batteries. Polymerization-induced\nphase separation is a facile one pot reaction to make these electrolytes.\nIt is a versatile method but requires control over the complex interaction\nof various parameters to tune the morphologies and properties of biphasic\nelectrolytes as it is highly system dependent. This study examines\nthe effects of thiol–ene chemistry and parameters such as porogen\ntype and content, thiol content, and salt concentration in the liquid\nelectrolyte, linking these factors to their curing behavior, morphology,\nand multifunctional properties. We present a toolbox showing how different\nmorphologies and properties can be reached by changing these parameters.\nThe porogen type and a 10% increase in the porogen content affected\nionic conductivity by an order of magnitude. Thiol–ene chemistry\naccelerates the curing process but reduces mechanical properties while\nslightly increasing the ionic conductivities for small amounts of\nthiol. The best negative structural electrode, containing carbon fibers\nas negative electrode, showed increased rate capability compared to\nprevious work and a discharge capacity of 219 mA h g<sup>–1</sup> at a current density of 18 mA g<sup>–1</sup> (∼0.08C).\nThe results also indicate the potential of applying the concept of\nhighly concentrated electrolytes in structural electrodes to improve\nsafety and capacity retention while maintaining high specific capacities\nand good rate capability. Interestingly, the increased ionic conductivity\nof the electrolyte does not always imply an improved electrochemical\nperformance of the structural electrode.