Facile Construction of High-Performance Amorphous FePO/Carbon Nanomaterials as Cathodes of Lithium-Ion Batteries.

A facile strategy to construct composites of amorphous FePO (a-FePO) nanoparticles and carbon additives with high dispersion and tap density was developed in this work, in which the a-FePO·2HO nanoparticles were handled without drying until being mixed with carbon nanomaterials in water to assure high dispersion of a-FePO·2HO nanoparticles and carbon nanomaterials; the controlled sedimentation was exploited by rapid adjustment of the pH value via a micromixer to obtain the composites that are easy to manipulate; the composites were endowed with high tap density after simple ball-milling. Using this strategy, hybrid carbon additives were uniformly introduced into the a-FePO cathode to form a hierarchical 3D conductive network. Through proper distribution of these components to provide both long- and short-range electron pathways, the reversible discharge capacity could reach 175.6 mA h g at 0.1 C and 139.1 mA h g at 5 C. The composites of a-FePO, carbon black, and carbon nanotubes (CNT) exhibited the distinct advantages of low cost and excellent rate capacity over the composites of a-FePO and CNT, indicating the importance of optimizing the hierarchical structure of cathode composites. The high effectiveness of this construction strategy to build a hierarchical conductive network is also promisingly used for the development of other functional nanocomposites.