Ultrasound-assisted synthesis of Li-rich mesoporous LiMn2O 4 nanospheres for enhancing the electrochemical performance in Li-ion secondary batteries

The hierarchically structured mesoporous LiMn₂O₄ (LMO) nanospheres were synthesized using a template-free self-assembly process that was coupled with ultrasound (U). The ultrasound technique suggested here is very powerful for controlling an ordered nanostructure and improving crystallinity with large single-crystalline domains. Owing to the hierarchical mesoporous structure and high crystallinity, U-LMO provides an excellent rate capability and cycle stability with a capacity retention of more than 98% up to 50 cycles at a 0.2 C rate. Here, we demonstrate that mesoporous U-LMO nanospheres were fabricated to enhance the electrochemical performance and protect it from structurally significant collapsing because of high crystallinity. © 2011 Elsevier B.V. All rights reserved.