Ultrathin Li₄Ti₅O₁₂ Nanosheets as Anode Materials for Lithium and Sodium Storage

Abstract

Ultrathin Li4Ti5O12 (LTO) nanosheets with ordered microstructures were prepared via a polyether-assisted hydrothermal process. Pluronic P123, a polyether, can impede the growth of Li2TiO3 in the precursor and also act as a structure-directing agent to facilitate the (Li1.81H0.19)Ti2O5·2H2O precursor to form the LTO nanosheets with the ordered microstructure. Moreover, the addition of P123 can suppress the stacking of LTO nanosheets during calcining of the precursor, and the thickness of the nanosheets can be controlled to be about 4 nm. The microstructure of the as-prepared ultrathin and ordered nanosheets is helpful for Li(+) or Na(+) diffusion and charge transfer through the particles. Therefore, the ultrathin P123-assisted LTO (P-LTO) nanosheets show a rate capability much higher than that of the LTO sample without P123 in a Li battery with over 130 mAh g(-1) of capacity remaining at the 64C rate. For intercalation of larger size Na(+) ions, the P-LTO still exhibits a capacity of 115 mAh g(-1) at a current rate of 10 C and a capacity retention of 96% after 400 cycles.

Two‐Dimensional Metal Oxide Nanomaterials for Next‐Generation Rechargeable Batteries

“…Porous NiCo 2 O 4 nanosheets synthesized via a microwave method followed by annealing in air have been studied as anode materials for LIBs, and they exhibited a high reversible capacity of 891 mA h g −1 at a current density of 100 mA g −1 , good rate capability, and stable cycling performance (with an average Coulombic efficiency of 97% from the second cycle). [323] For LIBs, the LTO nanosheets delivered a higher capacity of over 130 mA h g −1 compared to that of LTO without P123 (<120 mA h g −1 ) at the high rate of 64 C. Furthermore, the retained capacity was 144 mA h g −1 after 400 cycles at 8 C, corresponding to a 0.015 mA h g −1 loss per cycle. [323] For LIBs, the LTO nanosheets delivered a higher capacity of over 130 mA h g −1 compared to that of LTO without P123 (<120 mA h g −1 ) at the high rate of 64 C. Furthermore, the retained capacity was 144 mA h g −1 after 400 cycles at 8 C, corresponding to a 0.015 mA h g −1 loss per cycle.…”

“…Ternary or multielement metal oxide nanosheets have also been extensively studied for energy-storage devices, such as NiCo 2 O 4 , [315][316][317][318][319] ZnCo 2 O 4 , [320] Li 4 Ti 5 O 12 , [321][322][323][324][325][326][327][328][329] Co 2 GeO 4 , [330] Zn 2 (OH) 3 VO 3 , [331] LiCoO 2 , [332,333] LiNiO 2 , [334,335] LiMn 2 O 4 , [336] NaTiO 2 , [337] NaCoO 2 , [338,339] NaMnO 2 , [340] Na 0.66 [Li 0.22 Ti 0.78 ] O 2 , [341] and 2D/2D hybrid or heterogeneous metal oxide nanosheets. [342][343][344] For example, NiCo 2 O 4 , with a spinelrelated structure, where Ni occupies the octahedral sites and Co is allocated octa-and tetrahedral sites, delivers high electrical conductivity and a theoretical lithium storage capacity of about 890 mA h g −1 .…”

Li4Ti5O12 Anode: Structural Design from Material to Electrode and the Construction of Energy Storage Devices

“…For the purpose of pure‐nanosheets synthesis, Feng et al . reported an ordered ultrathin Li 4 Ti 5 O 12 nanosheets (P‐LTOs) synthesized by a P123‐assisted hydrothermal route . It has been proved that P123 could serve as the structure‐directing agent.…”

Wet‐chemistry synthesis of Li4Ti5O12as anode materials rendering high‐rate Li‐ion storage

“…They achieved remarkable results for enhancing the electrochemical properties of LTO. For example, Feng et al hydrothermally synthesized ultrathin LTO nanosheet with an initial discharge capacity of 193 mAh g −1 at the current rate of 0.2 C (~175 mA g −1 ) . Chou et al synthesized LTO microspheres by combining microwave‐assisted hydrothermal method with microwave‐based postannealing process.…”