Enhanced high rate and low-temperature performances of mesoporous LiFePO4/Ketjen Black nanocomposite cathode material

•Synthesizing LiFePO4 within particles size about 10 nm embedded in the mesoporous Ketjen Black by liquid deposition method.•LiFePO4 deposition in Ketjen Black exhibits an excellent electrochemical performance both at room temperature and low temperature.•The conductive “bridge” built by KB link the LiFePO4 particles with each other and facilitates the transportation of lithium ions and electrons.

The well-crystallized LiFePO4 cathode material was synthesized by liquid deposition method using mesoporous Ketjen Black (KB) as template. The LiFePO4/KB nanocomposite was characterized by X-ray diffraction (XRD), TG, SEM, HR-TEM, nitrogen sorption, galvanostatic charge/discharge test and EIS. The results indicate that the LiFePO4 particles about 10 nm were embedded in the mesoporous of Ketjen Black. The composite has an uniform particle size and 3D network structure, which delivers a discharge capacity of 120.2 mAh/g, 100.1 mAh/g, 85.5 mAh/g and 64.5 mAh/g at 1C, 5C, 10C and 20C under −20 °C respectively. Moreover, the composite also exhibit relatively high cycling performance and the capacity maintains 93.6% at 5C and 91.2% at 10C under −20 °C after 200 cycles. The stable high rate performance possibly fulfills the requirements of rechargeable lithium batteries for high power applications especially at low temperature.