Facile solvothermal synthesis of ultrathin LiFexMn1−xPO4 nanoplates as advanced cathodes with long cycle life and superior rate capability†
Abstract
Fe doping is widely used to improve the electrochemical performance of LiMnPO4 by “implanting” the merits of high rate capability and long cycle life of LiFePO4 into LiMnPO4. Nevertheless, great challenges still remain to obtain high-performance LiFexMn1−xPO4 at a low x value. In this work, we synthesized ultrathin LiFexMn1−xPO4 (x ≤ 0.15) nanoplates by a facile, controllable method. The plate-like LiFexMn1−xPO4 with a small lateral size (40–100 nm) and thickness (10–20 nm) exhibits high electrochemical activity, excellent rate capability and superior cycling stability after carbon coating. At a rate as high as 50C (8.5 A g−1), the LiFe0.15Mn0.85PO4/C composite can still yield a high discharge capacity of 96.2 mA h g−1 where the discharge process can be completed in only 40 s. LiFe0.15Mn0.85PO4/C can sustain a long-term cycling up to 1000 cycles at 10C with a capacity retention close to 70%. The fast and stable cycling ability of LiFexMn1−xPO4 makes it promising for applications in electric vehicles and hybrid electric vehicles.