Effect of ultrasonic pretreatment on electrochemical performance of LiFe0.5Mn0.5PO4/V/C composite in lithium-ion battery cathode

It is a great challenge to produce a battery with electrochemical properties. Efforts have been conducted by researchers to produce batteries with good capacity and long-life cycle. In this work, a series of batteries consisted of LiFe0.5Mn0.5PO4/V/C composite cathode have been successfully synthesized via hydrothermal method with and without ultrasonic pretreatment. Lithium hydroxide, ammonium phosphate, manganese sulfate monohydrate, and iron phosphate heptahydrate were used as starting materials. Citric acid was added as both carbon source and reducing agent, and vanadium salts was added as dopant to improve the retention time for longer life cycle. Characterization was performed by scanning electron microscope equipped with energy dispersive X-ray spectroscopy for morphology and elemental composition, X-ray diffraction for crystal structure, and cyclic voltammetry for electrochemical properties. The results showed agglomerated structure for sample without ultrasonic pretreatment and fine octahedral structure for sample with ultrasonic pretreatment, a distinctive x-ray diffraction pattern and high voltage up to 4.4 V for the potential difference. More works are yet to be further done for the improvement of the capacity.