Engineering Titanium Dioxide Nanostructures for Enhanced Lithium-Ion Storage

Abstract

Various kinds of nanostructured materials have been extensively investigated as lithium ion battery electrode materials derived from their numerous advantageous features including enhanced energy and power density and cyclability. However, little is known about the microscopic origin of how nanostructures can enhance lithium storage performance. Herein, we identify the microscopic origin of enhanced lithium storage in anatase TiO 2 nanostructure and report a reversible and stable route to achieve enhanced lithium storage capacity in anatase TiO 2 . We designed hollow anatase TiO 2 nanostructures composed of interconnected ∼5 nm sized nanocrystals, which can individually reach the theoretical lithium storage limit and maintain a stable capacity during prolonged cycling (i.e., 330 mAh g −1 for the initial cycle and 228 mAh g −1 for the 100th cycle, at 0.1 A g −1 ). In situ characterization by X-ray diffraction and X-ray absorption spectroscopy shows that enhanced lithium storage into the anatase TiO 2 nanocrystal results from the insertion reaction, which expands the crystal lattice during the sequential phase transition (anatase TiO 2 → Li 0.55 TiO 2 → LiTiO 2 ). In addition to the pseudocapacitive charge storage of nanostructures, our approach extends the utilization of nanostructured TiO 2 for significantly stabilizing excess lithium storage in crystal structures for long-term cycling, which can be readily applied to other lithium storage materials.

Polyoxometalates: Tailoring metal oxides in molecular dimension toward energy applications

“…289 The detailed mechanisms of -NH 2 and -OH groups in PMo 12 -based polyoxomolybdate for battery application are evaluated theoretically, revealing the importance of π-π stacking between graphene and polyoxomolybdate. 290 Furthermore, The Dawson-type polyoxomolybdate P 2 Mo 18 O 62 6− is bonded to the graphene oxide with superior polyoxometalate attachment via ionic liquids for enhanced lithium storage, 291 while PMo 12 /polypyrrole/reduced graphene oxide composite is fabricated for lithium-ion battery, which exhibits uniform distribution of polyoxometalate on graphene oxide surface owing to the presence of polypyrrole. 292 Comparatively, polyaniline/PMo 12 O 40 ] 3− composite nanofibers are employed for lithium-ion batteries, with the one-dimensional structure accommodating the volume change.…”

“…(b) TiO 2 in lithium‐ion battery to store lithium ions. Reproduced with permission from Lee et al Copyright ACS (2018) . (c) ZnO and NiO in perovskite cells, with a schematic view of the device cross section and the energy level alignment.…”

Mesoscopic open-eye core–shell spheroid carved anode/cathode electrodes for fully reversible and dynamic lithium-ion battery models

“…Due to its naturally occurring advantages including high safety, economics, ecofriendly, and low surface energy polarization, the TiO 2 (TO)anatase anode exhibited unique electrochemical performances with high stability of its life cycling. [43][44][45][46][47] The high cycling stability and reversibility of the anode N electrode design can be attributed to the facile structural phase transition from TOtetragonal I4 1 /amd symmetry to lithium-rich phase symmetry with Imma-orthorhombic Li 0.5 TiO 2 structures. 48 Thus, if the fabricated TO-tetragonal I4 1 /amd materials can be hybridized with hierarchical building blocks, multifunctional interface surfaces, a variety of binding site interactions, and mobile phase surface topographies, then the TO-anodic electrodes would offer highly optimized LIB designs for a high specic energy density battery and outstanding rate capability of rechargeable batteries.…”

Dynamics of Lithium Insertion in Electrochromic Titanium Dioxide Nanocrystal Ensembles

“…Nanostructured anatase TiO2 is a candidate Li-ion anode with moderate specific capacity and excellent cycle stability at (dis)charging rates relevant to transportation applications. [6][7][8][9][10][11][12][13][14] The rate at which battery electrodes, including nanostructured anatase, can be reliably charged and discharged depends on the kinetics of charging processes, including surface capacitance, phase transformations due to Li-ion intercalation, and conversion reactions. [15][16][17] An assortment of in situ and in operando characterization tools have been developed to observe these processes, and inform developments in mesoscale architecture, electrode particle morphology, composition and surface chemistry of mature and frontier electrode materials.…”

“…Titania and lithium titanate polymorphs, including spinel Li4Ti5O12, [23][24][25][26][27][28] anatase, [6][7][8][9][10][11][12] TiO2-B bronze [29][30][31][32][33] and amorphous phases, [34][35][36][37] are prototypical Li-ion anodes that charge through lithium insertion and surface reactions in nanostructured electrodes. In particular, anatase TiO2 has charge storage densities competitive with conventional graphite electrodes and a small volume change during Li-ion insertion that allows for high cycle and calendar lifetimes at fast charging rates.…”