Ascorbic acid-assisted solvothermal synthesis of LiMn<sub>1-x</sub>Fe<sub>x</sub>PO<sub>4</sub>/C nanoparticles for high-performance Li-ion cathode materials
Jing Li, Chaowei Guo, Yuanbin Qin, Xiaohui Ning
Abstract
LiFePO4 is a promising cathode material for lithium-ion batteries due to its excellent rate capability and superior safety. However, its relatively low energy density makes the research efforts towards another olivine structure material LiMnPO4, which exhibits higher energy density and operating voltage. Nevertheless, LiMnPO4 does not show the remarkable electrochemical performance attributing from the low electronic/ionic conductivity. To solve the problems, a facile solvothermal method is used to successfully synthetise the LiMn1-xFexPO4/C with different Fe/Mn ratio (LMFP/C) nanoparticle in this paper. The length of the obtained LiMn1-xFexPO4/C is less than 200 nm. Owing to the doping of iron and the nano-structure, the LiMn0.5Fe0.5PO4/C nanoparticle exhibits high discharge capacities of 153.6, 143.2 and 134.5 mAh g−1 at rates 0.1 C, 1 C and 5 C, respectively. Furthermore, the effects of pH on the morphology evolution and electrochemical performance have been also investigated in detail.