Lithium Storage in Nanodimensional TiO₂/Carbon Nanosheet Composites: Implications for Battery Applications

Abstract

Two-dimensional (2D) TiO 2 /carbon nanosheet (NS) composites have been demonstrated to exhibit higher Li + intercalation specific capacity as the electrode materials for Li-ion batteries compared to the theoretical capacity of TiO 2 according to our previous work. In order to demonstrate the Li + storage mechanism, TiO 2 nanoparticles (NPs), NSs, and nanotubes (NTs) with a highly regular arrangement into layered carbon NSs are constructed in the current work. Benefiting from the high interfacial charge storage of the TiO 2 NS/carbon NS superlattice structure, carbon/TiO 2 NSs exhibit a better Li + intercalation ability compared to NPs and NTs. The highest capacity of 575 mA h g −1 is obtained at 0.1 A g −1 for the carbon/TiO 2 NS composite. In addition, a high capacity of 79 mA h g −1 still remains even at a discharge current of 12.8 A g −1 . The effect of the 2D layered superlattice structure can promote rapid electron transport between carbon NSs and TiO 2 NSs. However, slow kinetics of ion intercalation occurs inside the TiO 2 NPs as well as on the surface of the TiO 2 NTs. The results reveal the importance of the interfacial charge storage in layered materials, which can deliver additional Li + storage capacity and provide theoretical and practical guidance for the construction of next-generation electrode materials with higher capacity, excellent rate performance, and outstanding structural stability.

Sand‐Fixation Model for Interface Engineering of Layered Titania and N/O‐Doped Carbon Composites to Enhance Potassium/Sodium Storage

“…Moreover, the rectangular shape suggests that the satisfactory specific capacity and cyclability are dominated by fast pseudocapacitive and double‐layer capacitive charge storage mechanism (Figure S15, Supporting Information). [ 14,40 ]…”

“…Moreover, the rectangular shape suggests that the satisfactory specific capacity and cyclability are dominated by fast pseudocapacitive and double-layer capacitive charge storage mechanism (Figure S15, Supporting Information). [14,40] To address it more clearly, the relationship between measured current (i) and scan rate (v) is shown in Equation ( 3). The bvalue is given by the slope of the log (v)-log (i).…”

“…[4][5][6][7][8] The barrier for widespread use is the large ionic radii of Na ion (1.02 Å) and K ion (1.38 Å), consequently making it challengeable to develop high-performance electrode materials. [9,10] Layered titania (L-TiO 2 ) is a typical layered metal oxide with high specific capacity (compared to their bulk counterparts), [11][12][13][14] moderate working voltage (≈0.6 V), and low cost. [15] The aforementioned advantages make it a promising anode for energy storage.…”

“…Layered titania (L‐TiO 2 ) is a typical layered metal oxide with high specific capacity (compared to their bulk counterparts), [ 11–14 ] moderate working voltage (≈0.6 V), and low cost. [ 15 ] The aforementioned advantages make it a promising anode for energy storage.…”