Lithium Ion Battery Anode of Mesocrystalline CoTiO₃/TiO₂ Nanocomposite with Extremely Enhanced Capacity

Abstract

Mesocrystalline materials consisting of nanocrystal subunit alignment with the same crystallographic orientation have a potential application as active materials for lithium ion battery (LIB) electrodes. In this study, a topochemical process was developed to synthesize mesocrystalline CoTiO3/TiO2 nanocomposites using a layered titanic acid H1.07Ti1.73O4 (HTO) precursor. The H2O2 treatment of HTO caused more Co2+ intercalation into the interlayer by the H+/Co2+ exchange reaction and the formation of a sandwich layered structure by stacking an HTO layer and a Co­(OH)2–x x+ layer. This sandwich layered structure was topotactically transformed into a mesocrystalline CoTiO3/TiO2 nanocomposite by heat treatment at >600 °C. The selected area electron diffraction result suggests that the CoTiO3/TiO2 nanocomposite is constructed from [010]-oriented CoTiO3 nanocrystals and [110]-oriented rutile TiO2 nanocrystals. The electrochemical results indicate that the mesocrystalline CoTiO3/TiO2 nanocomposite exhibits an extremely enhanced anode capacity of about 400 mAh/g for LIB, which is 2 times higher than that of polycrystalline CoTiO3. The excellent anode performance can be ascribed to the high mobility of Li+ in the mesocrystalline nanocomposite and the synergistic effect of TiO2 nanocrystals in the nanocomposite by enhancing the cycling stability and electron conductivity.

Topochemical synthesis of Mn2O3/TiO2 and MnTiO3/TiO2 nanocomposites as lithium-ion battery anodes with fast Li+ migration and giant pseudocapacitance via the mesocrystalline effect

“…The mesocrystalline materials consist of oriented nanocrystals, in which the Li + migration is relatively fast. 28,29 As shown in Fig. 8(e), when Li + migrates from a Mn 2 O 3 or MnTiO 3 nanocrystal to the next Mn 2 O 3 or MnTiO 3 nanocrystal with the same orientation in the mesocrystalline material, the migration distance in the interface passage will be shorter compared with that of a Mn 2 O 3 or MnTiO 3 nanocrystal with random orientation in the polycrystalline material.…”

“…[24][25][26][27] Furthermore, we have synthesized mesocrystalline MTiO 3 /TiO 2 (M = Co, Ni) nanocomposites from M 2+ ionexchanged layered titanates and demonstrated that the mesocrystalline MTiO 3 /TiO 2 nanocomposites can provide a short distance for charge transport and efficient Li + immigrating passage for Li + insertion/extraction reactions, which results in an enhanced specific charge-discharge capacity. 28,29 However, to the best of our knowledge, the study on the Li + insertion/ extraction reaction of mesocrystalline Mn 2 O 3 in LIBs has not been reported.…”

Structure, Properties, Preparation, and Application of Layered Titanates

“…Copyright 2018 Elsevier B.V. (c) Schematic diagram of Li + migration passage in CoTiO 3 mesocrystalline material. Reproduced from ref . Copyright 2021 American Chemical Society.…”

Mesocrystalline effect in a NiTiO3/TiO2 nanocomposite for enhanced capacity of lithium-ion battery anodes

“…The mesocrystalline CoTiO 3 /TiO 2 nanocomposite exhibits a much larger reversible capacity than that of polycrystalline CoTiO 3 . 37…”

“…The mesocrystalline CoTiO 3 / TiO 2 nanocomposite exhibits a much larger reversible capacity than that of polycrystalline CoTiO 3 . 37 In this paper, firstly we studied the exfoliation reaction of H 2 O 2 -HTO and found that it can be exfoliated into H 2 O 2 -HTO nanosheets for the first time and the reaction is much quicker than that of the original HTO. The exfoliated H 2 O 2 -HTO nanosheets can be used to synthesize a polycrystalline NiTiO 3 / TiO 2 nanocomposite with high NiTiO 3 content.…”