One-pot synthesis of uniform Fe₃O₄ nanospheres with carbon matrix support for improved lithium storage capabilities.

Poly(acrylic acid) (PAA)-entangled Fe(3)O(4) nanospheres are synthesized via a facile solvothermal method. In this system, ethylenediamine plays a very important role to control the uniformity of the nanospheres, and the PAA molecules serve as the carbon source that transforms into a carbon matrix after the heat treatment under an inert atmosphere. These uniform Fe(3)O(4) nanospheres with carbon matrix support manifest greatly enhanced lithium storage properties over prolonged cycling, with a reversible capacity of 712 mA h g(-1) retained after 60 charge/discharge cycles. However, the carbon-free counterpart can only deliver a much lower capacity of 328 mA h g(-1).