The research on the electrochemical performance of Li₂FeSiO₄/mg_x and Li₂FeSiO₄/cu_x

Abstract

Two lithium ions can be reversibly embedded/detached from the structure of Li₂FeSiO₄, thus having a high theoretical discharge specific capacity. However, it has the defects of low conductivity and slow lithium ion diffusion rate, which makes it difficult to realize the deintercalation of more than one lithium ion, and its actual discharge specific capacity is lower than the theoretical capacity. This greatly restricts its development into commercial battery cathode materials. In this paper, Li₂FeSiO₄/Mg_x and Li₂FeSiO₄/Cu_x (x = 0.01, 0.02, 0.03, 0.05) are synthesized by solid-state method. The electrochemical performance of Li₂FeSiO₄/Mg_0.03 and Li₂FeSiO₄/Cu_0.02 is the most stable. The initial discharge capacity of Li₂FeSiO₄/Mg_0.03 is 147 mAh/g, the capacity retention is 84.2% after 10 cycles under 0.1 C. The initial discharge capacity of Li₂FeSiO₄/Cu_0.02 is 140.9 mAh/g. There is only slight agglomeration in Li₂FeSiO₄/Mg_0.03 and Li₂FeSiO₄/Cu_0.02 from the SEM. The crystal cell volume of Li₂FeSiO₄/Cu_0.02 increases slightly, which is conducive to improving the electrochemical performance.

Keywords:

• Li₂FeSiO₄
• solid-state method
• Li-ion battery
• electrochemical performance

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

Sponsored by Natural Science Foundation of Henan, Foundation No. 202300410009.