In
this article, nanostructured amorphous FePO4 (a-FePO4)–carbon nanotube (CNT) composites, with high purity
of FePO4 and a controllable FePO4/C ratio, were
directly synthesized by a fast nanoprecipitation process in a microreactor,
using Fe(NO3)3 and (NH4)3PO4 as precursors. Oxidized CNTs are well dispersed via
strong electrostatic repulsion in a high pH solution system. Subsequently,
a-FePO4 nanoparticles are adhered onto CNTs just following
the fast nanoprecipitation process; then, the precipitated composites
are compacted by ball-milling, forming a compact conductive network
with well dispersed and highly loaded active materials. As cathode
materials for lithium-ion batteries, the composites exhibit a capacity
of 175.8 mAh g–1 at 0.1 C, close to the theoretical
capacity (178 mAh g–1), and a good cycle performance
with a reversible capacity of 137.0 mAh g–1 after
500 cycles at 5 C. Importantly, the enhanced micromixing enables fast
nanoprecipitation in suspension and opens a shortcut for constructing
nanostructured composites that have potential in functionalization
and are easy to handle.