In situ monitoring of TiO₂(B)/anatase nanoparticle formation and application in Li-ion and Na-ion batteries

Abstract

Bronze phase, TiO2(B), and anatase nanoparticles in various weight fractions and with different sizes have been synthesized by a very facile method and their electrochemical performances have been evaluated in Li-and Na-ion cells. The transition from a layered hydrogen-titanate precursor to TiO2(B)/anatase mixtures was monitored by in situ powder X-ray diffraction from room temperature to 800°C. Simple NaOH treatment of the precursor inhibited the transformation of precursor and TiO2(B) to anatase at elevated temperatures and allowed for preparation of larger TiO2(B) crystallites with extra high thermal stability.

Architectural design and phase engineering of N/B-codoped TiO2(B)/anatase nanotube assemblies for high-rate and long-life lithium storage

“…Impressively, a capacity of 160 mA h g À1 with a high initial columbic efficiency of 94.8% (retaining 67.5% of the capacity at 0.5 A g À1 ) can still be gained at a superhigh charging-discharging rate of 12 A g À1 , representing the superior rate performances ever achieved for TiO 2based materials. [11][12][13][14][15][17][18][19][20][21][22][26][27][28][29][30][31][32][49][50][51][52] The capacities towards the current densities of the assembled TiO 2 nanotubes and previously reported TiO 2 electrodes plotted in the Ragone diagram (Fig. 4d) directly demonstrate the superior rate capability of the assembled TiO 2 nanotubes in this work.…”

“…Theoretically, TiO 2 can store one Li + ion per formula unit with a similar potential range and a higher specic capacity of 335 mA h g À1 (nearly a twofold increase over the capacity of Li 4 Ti 5 O 12 ). [11][12][13][14][15][16][17][18][19][20][21][22] Among the TiO 2 polymorphs, the monoclinic TiO 2 (B) is an exception because it can deliver enhanced power capability and bulk capacity. 23,24 Intriguingly, the crystal structure of TiO 2 (B) features channels that are parallel to the b-and caxes.…”

Recent advances in hierarchical anode designs of TiO2‐B nanostructures for lithium‐ion batteries

“…From the morphological and structural perspectives, TiO 2 exists in nature under four polymorphs, in which anatase and rutile are applied more in solar cells and photocatalysis areas, 9,10 whereas TiO 2 -B is a better choice for LIB applications at ultra-high current rates, as reported in the literature. [11][12][13] However, some issues arising from the insufficient reaction kinetic such as poor electrical/ionic conductivity, low Li + diffusion coefficient, and wide-bandgaps, have hampered the practical applications of TiO 2 -B. [14][15][16] Furthermore, as a typical metal oxide, TiO 2 -B directly joins the redox process of active materials following the formation and decomposition of Li 2 O, which may result in unsafety and failure conditions in LIBs.…”

Na-ion Hybrid Energy Storage Devices Based on Nanoengineered Electrodes

“…Subsequent charge compensation and strain during Na-ion intercalation cause reversible Ti 4+ reduction. 124,156,164,165,177,178 Complete sodiation of the dual-phase TiO2 nanosheets, in this case, results in an only minor change of lattice parameters compared to previous reports, where the storage mechanism involves diffusion-dependent insertion/conversion reactions. Hence, Na-ion storage involves the pseudocapacitive intercalation reaction rather than surface storage on TiO2 nanosheets.…”

“…This often resulted in the inadequate energy densities of SHCs based on TiO2 anodes. 53,119,155,156 Although charge-transfer and intercalation type pseudocapacitive Li-ion storage of These additional signals originate from oxygen/moisture adsorbed at oxygen vacancies and carbonate groups (resulting from Ti-glycolate decomposition), respectively. 159,160 The presence of oxygen vacancies and moisture is common for low-temperature-treated highsurface TiO2, especially for the (110) plane of the bronze polymorph.…”