A practical and effective strategy for the thin and uniform carbon layer onto LiCoPO4 cathode surface in terms of the rate capability and cycle stability

• Structural, morphological and electrochemical properties of LiCoPO4/C electrodes are investigated.
• Cheap and simple microwave & solvothermal approach is used.
• After 80th cycle, capacity retention is almost 91% for LiCoPO4/C electrode.
• Tannic acid was used as carbon source and its unique effects were revealed.

Nanoscale pure LiCoPO4 and LiCoPO4/C materials were successfully synthesized as excellent quality cathode materials for high-voltage and high energy density lithium-ion applications. These materials are simply produced by combined magnetron power and the solvothermal method followed by heat treatment. Analyses show that distribution of a surface coated with carbon, 5–7 nm thickness by tannic acid and nanostructured LiCoPO4/C cathode exhibits a higher and stable reversible capacity (155.2 mAh g−1) with the long voltage plateau nearly 4.8 V. Furthermore, this cathode exhibits capacity retention as 91% after 80 cycles and this value makes it one of the highest of those reported to date. The LiCoPO4/C electrode is produced simultaneously under high pressure and using microwave energy and this has an influence on excellent cycling behavior. The obtained results prove that a production dynamics in nano-synthesis and coating process with proper carbon source reveal parameters to synthesis favorable cathode materials.

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