LAUSR

Abstract In this work, a three-dimensional ordered hierarchically porous (3DOHP) Li 4 Ti 5 O 12 that possesses inner-particle mesopores resulting from a soft template method and a three-dimensional ordered macroporous (3DOM) Li 4 Ti 5 O 12 using polystyrene spheres as a hard template have been synthesized. Both 3DOM Li 4 Ti 5 O 12 and 3DOHP Li 4 Ti 5 O 12 have ordered macropores and interconnected skeletons with a regular periodicity revealed by SEM and TEM observations. The specific surface area of 3DOHP Li 4 Ti 5 O 12 is up to 135 m 2  g −1 which is much higher compared with that of 3DOM Li 4 Ti 5 O 12 because of the existence of inner-particle mesopores. Attributed to the higher surface area and smaller crystal grain size, more excellent cycle performance and rate capability are obtained for 3DOHP Li 4 Ti 5 O 12 compared to 3DOM Li 4 Ti 5 O 12 . In addition, the hierarchically porous structure of 3DOHP Li 4 Ti 5 O 12 can meet rapid insertion and deinsertion of lithium ion even at extremely high rate. It is apparent that 3DOHP Li 4 Ti 5 O 12 has a lower total resistance and faster Li + diffusion coefficient compared to 3DOM Li 4 Ti 5 O 12 according to electrochemical impendence spectroscopy analysis.