Low‐temperature Synthesis of Peony‐like Spinel Li₄Ti₅O₁₂ as a High‐performance Anode Material for Lithium Ion Batteries

Abstract

Peony-like spinel Li 4 Ti 5 O 12 was synthesized via calcination of precursor at the temperature of 400 ℃, and the precursor was prepared through a hydrothermal process in which the reaction of hydrous titanium oxide with lithium hydroxide was conducted at 180 ℃. The as-prepared product was investigated by SEM, TEM and XRD, respectively. As anode material for lithium ion battery, the Li 4 Ti 5 O 12 obtained was also characterized by galvanostatic tests and cyclic voltammetry measurements. It is found that the peony-like Li 4 Ti 5 O 12 exhibited high rate capability of 119.7 mAh•g -1 at 10 C and good capacity retention of 113.8 mAh•g -1 after 100 cycles at 5 C, and these results indicate the peony-like Li 4 Ti 5 O 12 has promising applications for lithium ion batteries with high performance.

Aqueous Synthesized Nanostructured Li4Ti5O12for High-Performance Lithium Ion Battery Anodes

“…These values compare favorably with other hydrothermally prepared LTO materials. [23][24][25][26]38 For example, according to Liu et al, the 1 C discharge capacity of nanoflower-like and nanoparticle LTO prepared by microwave-assisted hydrothermal synthesis and annealed at 550 • C for 6 hours exhibited initial discharge capacities of 176.7 and 109.8 mAh g −1 respectively 26 vs. 153.5 (nanosheets) and 155.2 (nanoparticles) mAh • g −1 of the present work. At the same time hydrothermally prepared LTO annealed at 600 • C, as reported by Shen et al, delivered 150 mAh • g −1 at 1 C but only 81.2 mAh • g −1 at 10 C, the latter improving to 140 mAh • g −1 after the same LTO was tested as graphene nanocomposite.…”

“…12,17,19 Furthermore, the voltage profile can be tailored via controlling the shape and morphology of nanostrucutred LTO. 17 In this context, nanostruutred LTO with different morphologies, such as nanotubes 14 and nanowires, 21 nanosheets [22][23][24][25][26] and nanoparticles [27][28][29][30] have been synthesized and tested.…”

“…To the best of our knowledge, LTH has been only prepared successfully previously by hydrothermal reaction using amorphous hydrous TiO 2 pre-prepared by hydrolyzing organic titanium precursors such as TTIP and tetrabutyl titanate (TBT). [23][24][25][26]30,37,38,44 According to the previous studies, 23,26,30 the electrochemical performance of the final nanostructured LTO product is highly dependent on the purity and crystallinity of LTH hence its annealing is very important.…”

Enhanced Performance of “Flower‐like” Li4Ti5O12 Motifs as Anode Materials for High‐Rate Lithium‐Ion Batteries

“…We should state at the outset that our synthesis protocol is simpler and less time consuming than the strategies used for other previously reported structures.I n terms of ad irect comparison of the electrochemical results, after approximately 50 cycles of testing, herein we observed ad ischarge capacity of approximately 140 mAh g À1 under 10 C discharge, whereas ap reviously reported "flower-like" Li 4 Ti 5 O 12 structure gave rise to approximately 150 mAh g À1 under 8C, [17] and ad ifferent" peony-like"L i 4 Ti 5 O 12 materialy ielded merely approximately 100 mAh g À1 under 10 Cd ischarge. [20] As another example, after approximately 65 cycles of testing, we noted ad ischarge capacity of 123 mAh g À1 observed at 50 C. By contrast, as imilar porous hierarchical Li 4 Ti 5 O 12 architecture previ- ously reported only delivered 121 mAh g À1 at a3 0C discharge rate, [21] and similarly,a na nalogous urchin-like Li 4 Ti 5 O 12 motif yielded ad ischarge capacity of 120.8 mAh g À1 at a2 0Crate. [27a] Notably,o ur as-prepared structures were tested under highrate discharge conditions, and it is notable that our as-prepared "flower-like" Li 4 Ti 5 O 12 maintained ac apacity of !…”

“…For instance, after 100 cycles, our capacity was 147 mAh g À1 under 0.2 C( i.e.,9 7% relative to cycle 10 and % 99 %f rom cycles 21-100)a nd 117mAh g À1 after 300 cycles under ar elatively high discharge rate of 20 C, which demonstrates not only comparable performance, relative to aprevious "flower-like" Li 4 Ti 5 O 12 motif, [17] but also, importantly,s ignificant capacityr etention improvement relative to prior dandelionlike [2a] and peony-like Li 4 Ti 5 O 12 materials. [20] Conclusions Nanostructured "flower-like" Li 4 Ti 5 O 12 structures were successfully synthesized by as imple and rapid hydrothermal method involving short reactiont imes, relatively low reactiont emperatures, in addition to reusablea nd recyclable Ti precursors. By taking advantage of the etching capability of the H 2 O 2 solution under hydrothermalc onditions, the resulting "flower-like" precursor to Li 4 Ti 5 O 12 possesses high surface area as well as au niform 3D layered morphology.U pon calcination at ar elatively low temperature of 500 8C, aw ell-crystallized final product was generated.…”