Synthesis and electrochemical performance of nanostructured LiMnPO4/C composites as lithium-ion battery cathode by a precipitation technique

• Well crystallized 100–300 nm MnPO4·H2O is achieved by a novel fast precipitation method.
• A in situ carbon coated LiMnPO4 is synthesized by mechanochemical activation assisted carbothermal reduction route.
• LiMnPO4/C sample with reduced carbon amount displays excellent discharge plateau and good rate capability.

A fast precipitation method is adopted for synthesis of nano-MnPO4·H2O, with MnSO4·H2O, H3PO4, NH4NO3 and NaOH as raw materials. MnPO4·H2O precipitate is characterized by XRD (X-ray diffraction) and SEM (scanning electron microscope). Fine-sized, well-crystallized, carbon-coated LiMnPO4/C nano-composites are obtained by using mechanochemical activation assisted carbothermal reduction route from as-prepared MnPO4·H2O, Li2CO3 and PVA (polyvinyl alcohol). The effect of calcination temperature on the structure and properties of obtained materials is investigated by XRD, SEM, TEM (transmission electron microscopy) and electrochemical measurements. The in situ 6.8 wt% carbon coated LiMnPO4/C displays discharge specific capacity of 124 mAh g−1 at 0.05 C rate and 108 mAh g−1 at 1 C rate. The capacity retention is nearly 100% after 20 cycles at 1 C rate. This mechanochemical activation assisted precipitation technique is a facile approach for the fabrication of LiMnPO4 cathode materials.

Fine-sized, well-crystallized, in situ carbon-coated LiMnPO4 powders with reduced carbon amount were obtained by a fast precipitation method, displaying good rate capability and cyclic stability with an excellent discharge plateau around 4.0 V vs. Li/Li+.Figure optionsDownload as PowerPoint slide