Improved high-rate performance and cycling stability of 1D LiFePO₄ nanorods by a facile annealing process

Abstract

To alleviate the main limitations of lithium ion diffusion rate and poor electronic conductivity for LiFePO₄ cathode material, it is desirable to synthesize nano-size LiFePO₄ material due to its enhanced electronic and lithium ion transport rates and thus an improved high-rate performance. However, our previous synthesized LiFePO₄ nanorods only exhibited low high-rate and slightly unstable cycle performance. Possible reasons are the poor crystallization and Fe²⁺ oxidation of LiFePO₄ nanorods prepared by hydrothermal method. In this paper, LiFePO₄ nanorods were simply dealt with at 700 °C for 4 h under the protection of Ar and H₂ mixture gas. The electrochemical properties of LiFePO₄/Li cells were investigated by galvanostatic test and cyclic voltammetry (CV). The experimental results indicated that the annealed LiFePO₄ nanorods delivered an excellent cycling stability and obviously improved capacity of 150 mA·h·g⁻¹ at 1C, and even 122 mA·h·g⁻¹ at 5C.

Keywords

LiFePO₄ / nanorod / annealing / cycle performance / high-rate / cathode material

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