Synthesis of 3D “micro-nano-structure” LiFePO4/C with high-rate capability and high tap density via a water bath process

The 3D “micro-nano-structure” LiFePO4/C have been synthesized successfully from FePO4·2H2O precursor via a simple, inexpensive and continuously water bath process at 100 °C for 24 h by using Fe3+ as the iron source, followed by a rheological phase method. Both the properties of the FePO4·2H2O and the LiFePO4/C were investigated by XRD and SEM. The results indicated that the 3D “micro-nano-structure” materials composited of nanoplates which are about 100 nm long and 50 nm thick, and had a hole in the center. Moreover, the FePO4·2H2O had a high yield above 85 %. Furthermore, the 3D “micro-nano-structure” LiFePO4/C as cathode materials for Li-ion batteries were also evaluated. The materials showed excellent high-rate capability, with discharge capacities reaching 103 and 80 mAh g−1 at high rates of 10 and 20 C, even could reach 40 mAh g−1 when the current increased to 30 C. Moreover, the LiFePO4/C had a high tap density about 1.5 g cm−3. As a result, the 3D “micro-nano-structure” LiFePO4/C can be the cathode material for large-scale applications and industrialization.