Partic. vol. 24 pp. 142-150 (February 2016)
doi: 10.1016/j.partic.2015.05.001

Controllable synthesis of Li₃PO₄ hollow nanospheres for the preparation of high performance LiFePO₄ cathode material

Jiaying Bi^a,b, Tongbao Zhang^a, Kai Wang^a, Benhe Zhong^b, Guangsheng Luo^a,*

gsluo@tsinghua.edu.cn

Abstract

Lithium phosphate hollow nanospheres were prepared in a membrane dispersion microreactor using aqueous phosphoric acid and lithium hydroxide solutions as reactants. The influences of reactant flow rate ratio and temperature on the purity and morphology of the prepared nanospheres were investigated using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The results showed that nanospheres prepared in the continuous flow condition had a hollow interior structure with high crystallinity. A possible mechanism for the formation of this hollow structured Li₃PO₄ was also proposed. Using Li₃PO₄ hollow nanospheres as the precursor, LiFePO₄ hollow nanospheres were successfully synthesized via a solvothermal route in ethylene glycol. After coating with carbon, the LiFePO₄/C hollow nanospheres exhibited excellent electrochemical performance, especially at high rates, and could discharge124 mAh/g at 10 C, and even 98 mAh/g at 40 C.

Graphical abstract

Keywords

Lithium phosphate; Hollow sphere; Microreactor; Lithium iron phosphate