Titanium oxide (TiO2) has attracted great interest as a promising anode material for lithium (Li) ion batteries (LIBs) and sodium (Na) ion batteries (SIBs). However, the key factors that dictate the Li-ion and Na-ion storage and transportation in TiO2 remain unclear. Herein, we report a facile hydrolysis route to crafting a variety of high tap-density TiO2 spheres with controllable size and hierarchical pores. The Li-ion and Na-ion storage properties based on these TiO2 spheres were systematically investigated. The pore distribution and the size of TiO2 spheres were found to exert profound influence on the Li-ion and Na-ion storage and transportation. The Li-ion storage and transportation in dense TiO2 spheres was dependent mainly upon the micropore distribution and volume and independent of the size of spheres. In contrast, the excellent Na-ion storage and transportation in TiO2 spheres was enabled by the loose structure with a large macroscopic pore volume and shortened Na-ion diffusion length. High tap-density TiO2 spheres (1.06 g cm-3) with superior Li-ion and Na-ion storage properties were produced, exhibiting a Li-ion storage specific capacity of 189 mA h g-1 at 1C and a high capacity retention of 88.1% after 100 cycles, and a Na-ion storage specific capacity of 184 mA h g-1 at 1C and capacity retention of 90.5% after 200 cycles. The ability to understand the critical factors controlling the Li-ion and Na-ion storage in high tap-density TiO2 spheres enables their implementation for practical applications in Li-ion and Na-ion batteries.
Bibliographical noteFunding Information:
This work was supported by the National Key Basic Research Program of China (2014CB932400), the National Natural Science Foundation of China (51232005), Shenzhen Basic Research Project (No. ZDSYS20140509172959981 and JCYJ20140417115840246), Youth research funds of the Graduate School at Shenzhen, Tsinghua University (QN20150002), Peng Cheng Scholar program (Z. L.) and Production-study-research cooperation project of Guangdong province (No. 2014B090901021) and Dongguan City (2015509119213).
© The Royal Society of Chemistry.