Enhancement of the electrochemical performance of LiCoPO4 by Fe doping

LiCoPO4 is an attractive cathode material, but it undergoes poor electronic conductivity and electrochemical performance. This performance is enhanced by substituting iron antisite Cobalt to reduce the direct interaction between the cathode and the electrolyte. Thus, LiCoPO4 doped with Fe was synthesized by the microwave assisted solvothermal route at 220 degrees C. According to X-ray diffraction analysis, a single orthorhombic Pn21a phase (a = 10.02 angstrom, b = 6.71 angstrom and c = 4.96 angstrom) was obtained, which transited to Pnma phase (a = 10.21 angstrom b = 5.92 angstrom and c = 4.76 angstrom) after annealing at 700 degrees C in air. The morphology and particle size of the sample changed after annealing, as shown by TEM. The electrochemical cycling of an annealed sample showed the initial discharge capacity of 125mAh g(-1) compared to 12 mAh g(-1) for the non-annealed sample, which can be regarded as a partial coating by FePO4 as obtained from X-ray absorption spectroscopy analysis.

Automated summary

LiCoPO4 doped with Fe was synthesized using a microwave assisted solvothermal route and showed improved electrochemical performance after annealing, with changes in crystal structure, morphology, and particle size. The electrochemical testing demonstrated a significant increase in initial discharge capacity for the iron-doped sample, indicating partial coating by FePO4.