UC Riverside

Lithium iron phosphate (LiFePO4) is an interesting candidate for Li-ion cathode applications because of its high theoretical specific capacity, good cycle stability, and environmentally friendly nature. However, its performance is limited due to its low electrical conductivity and low ionic diffusivity. Therefore, synthesis methods need to be developed to improve its electrochemical performance. One effective approach is to learn from since inorganic-organic hybrid materials are formed through the mineralization process where of inorganic materials are nucleated and grown in the presence of an organic matrix that controls the crystal morphology, size, and orientation. Here, this work focuses on the investigation of biologically-inspired synthesis of LiFePO4 using a modified solvothermal method. Specifically, we study the crystal growth kinetics of LiFePO4 in order to establish a platform for understanding crystallization behavior at higher temperatures, where these cathodes are annealed to during carbon deposition. Secondly, we examine growth of LiFePO4 under solvothermal conditions modified with a ligating polymer that controls the solution environment and subsequently nucleation of LiFePO4 crystals. Finally, we utilize a structural polymer that acts as a scaffold to regulate porosity in order to fabricate nanoporous cathodes with enhanced Li-ion intercalation kinetics and thus, an improvement on the electrochemical performance. Crystallization is interrogated using X-ray diffraction, SEM and TEM while porosimetry is used to measure surface area and FTIR and TGA are performed to confirm the presence of organic in the samples. Cyclic voltammetry is used to measure electrochemical performance