Effect of Precursor Concentration on the Electrical Properties of LiFePO_4 Prepared by Solvothermal Method

摘要

Lithium iron phosphate (LiFePO_4) is frequently used for Li-ion battery cathode. LiFePO_4 has the high specific capacity at 170 mAhg~(-1), stable voltage at 3.45 V, stable structure, cheap, and low toxicity. The objective of this research is investigating the effect of precursor concentration on the electrical properties of LiFePO_4 prepared by solvothermal method. LiOH, FeSO_4, H_3PO_4, and citric acid were used as the precursors. The LiOH concentration was varied from 0.3 M to 1.8 M. The Fourier Transform Infrared Spectroscopy (FTIR) measurement identified the Fe-O, O-P-O, and P-O bonds which corresponding to LiFePO_4. The result of 4-point probe measurement shows that, among the prepared samples, the sample from the precursor concentration of 1.8 M has the highest electrical conductivity.