Effect of argon sputtering pressure on the electrochemical performance of LiFePO₄ cathode

The development of a novel small-scale electrical power source technology is essential in the design of microelectronic devices. In this sense, this study presents the optimization of the sputtering deposition parameters to grow a LiFePO₄ cathode, a candidate material for the development of solid-state lithium batteries. Specifically, it was evaluated the effect of argon deposition pressure on the electrochemical properties of LiFePO₄ cathode. By combining X-ray photoelectron spectroscopy with electrochemical characterization methods, it was revealed that argon deposition pressure modulated the degree of the re-sputtering effects. In addition, it was found that high argon deposition pressure leads to the growth of LiFePO₄ films with oxygen and phosphor deficiency. The absence of these atoms caused the decrease in the LiFePO₄ electrochemical activity. Conversely, deposition parameters based on low argon sputtering pressure significantly reduced the degree of the re-sputtering effects, which in turn favored the growth of stoichiometric LiFePO₄ films with an enhanced electrochemical activity.