Electrochemical properties of yolk–shell and hollow CoMn2O4 powders directly prepared by continuous spray pyrolysis as negative electrode materials for lithium ion batteries

Abstract

Yolk–shell and hollow CoMn2O4 powders are prepared directly by spray pyrolysis from aqueous spray solutions with different concentrations of sucrose. Phase pure tetragonal CoMn2O4 powders without impurity phases are prepared even without post-treatment. The powders prepared from a spray solution with a low sucrose concentration of 0.1 M have a hollow structure. The single and double-shelled yolk–shell powders prepared from spray solutions with 0.4 and 0.7 M sucrose, respectively, have high discharge capacities of 519 and 573 mAh g−1 in the voltage range of 0.01–3 V, respectively, after 40 cycles at a high discharge rate of 800 mA g−1. However, the thick- and thin-shelled hollow powders prepared from spray solutions without and with 0.1 M sucrose have low discharge capacities of 418 and 276 mAh g−1 after 40 cycles, respectively. The discharge capacities of the yolk–shell powders are as high as 579, 530, and 443 mAh g−1 at discharge rates of 1600, 2400, and 3200 mA g−1 after 40 cycles, respectively.