Development of solid-state composite cathode material for solid-state lithium-ion batteries based on lithium ferrophosphate LiFePO4

In the past few decades all-solid-state lithium-ion batteries have become a promising frontier due to their increased safety, higher energy density and unique mechanical properties. One of the main issues in this field is establishing  steady transport of lithium ions across the electrode–electrolyte interface, which requires modifications of the electrode structure. In this research we investigated mechanical properties, capacity and cycling performance of a composite cathode based on solid polymer electrolyte as a binder, lithium ferrophosphate as active material and carbon black as electron conductor. Composite cathode was prepared with the help of ball-milling to reduce the particle  size and increase the homogeneity of the material, which resulted in mechanically stable flexible crack-free electrodes after coating, drying and calendaring. Achieved specific capacity of the electrodes corresponds to  theoretical values, electrodes show long-term sustainability in systems with liquid electrolyte and are applicable to solid-state systems.