Synthesis of micro-nano hierarchical structured LiFePO4/C composite with both superior high-rate performance and high tap density

Efforts were made to synthesize LiFePO4/C composites showing both high rate capability and high tap density. First, monoclinic phase FePO4 center dot 2H(2)O with micro-nano hierarchical structures are synthesized using a hydrothermal method, which are then lithiated to LiFePO4/C also with hierarchical structures by a simple rheological phase method. The primary structures of FePO(4 center dot)2H(2)O are nanoplates with similar to 30 nm thickness, and the secondary structures of the materials are intertwisted micro-scale rings. The LiFePO4/C materials lithiated from these specially structured precursors also have hierarchical structures, showing discharge capacities of more than 120, 110, and 90 mAh g(-1) at rates of 5 C, 10 C and 20 C, respectively, and high tap density of 1.4 g cm(-3) as cathode materials for lithium ion batteries. Since tap density is an important factor that needs to be considered in fabricating real batteries in industry, these hierarchical structured LiFePO4/C moves closer to real and large-scale applications.