Amorphous Ultrathin TiO₂Atomic Layer Deposition Films on Carbon Nanotubes as Anodes for Lithium Ion Batteries

Abstract

Amorphous TiO 2 (a-TiO 2 ) thin films were conformally coated onto the surface of hydroxyl functionalized multi-walled carbon nanotubes (CNTs) using atomic layer deposition (ALD). The electrochemical characteristics of the a-TiO 2 /CNT nanocomposites were then determined using cyclic voltammetry and galvanostatic charge/discharge curves. The ultrathin TiO 2 ALD films displayed high specific capacity and high rate capability. The specific capacities of the a-TiO 2 /CNT nanocomposites after 50 and 100 TiO 2 ALD cycles at 100 mA/g were 220 mAh/g and 240 mAh/g, respectively. For CNTs coated with 100 TiO 2 ALD cycles, 88% of the capacity at 100 mA/g could be maintained at 1 A/g. When the voltage window for the a-TiO 2 /CNT nanocomposites was extended down to 0.5 V versus Li/Li + , the CNTs coated with 50 and 100 TiO 2 ALD cycles exhibited specific capacities at 100 mA/g of 275 mAh/g and 312 mAh/g, respectively. These high capacities are higher than the bulk theoretical values and are attributed to additional interfacial charge storage resulting from the high surface area of the a-TiO 2 /CNT nanocomposites. Free-standing TiO 2 -CNT electrodes were also fabricated and displayed excellent capacity and rate capability. These results demonstrate that TiO 2 ALD on high surface area CNT substrates can provide high power and high capacity anodes for lithium ion batteries.

Fullerene as a Photoelectron Transfer Promoter Enabling Stable TiO2‐Protected Sb2Se3 Photocathodes for Photo‐Electrochemical Water Splitting

“…Figure 4a,b shows the spectra of the Ti 2p region of PTS and PC 60 TS, respectively, as a function of operation time. [32,33] As PEC operation duration increased, the binding energy gradually shifted to a lower level (see the dotted lines), revealing an additional satellite peak at ≈457 eV (see Figure S8a and Table S1, Supporting Information, for detailed fitting curves). [32,33] As PEC operation duration increased, the binding energy gradually shifted to a lower level (see the dotted lines), revealing an additional satellite peak at ≈457 eV (see Figure S8a and Table S1, Supporting Information, for detailed fitting curves).…”

Current Advances in TiO2-Based Nanostructure Electrodes for High Performance Lithium Ion Batteries

“…These characteristics are strongly desired to manufacture LIBs in large quantities suitable for mobile and stationary storage applications. Nevertheless, the poor electrical conductivity, low ionic diffusivity, and low theoretical capacity of TiO 2 (335 mAh g −1 ) are the main obstacles hindering the production of high-performance LIBs with titania anodes [24,26]. The reported reversible capacity of bulk TiO 2 is only 180 mAh g −1 , i.e., half of its theoretical capacity [27,28].…”

Titanium Dioxide/Lithium Phosphate Nanocomposite Derived from Atomic Layer Deposition as a High‐Performance Anode for Lithium Ion Batteries

“…The Li + ion diffusion coefficient in anatase TiO 2 is ≈10 −13 –10 −17 cm 2 s −1 . The electronic conductivity of anatase is also low at ≈10 −12 S cm −1 . The problems can be addressed from two perspectives.…”

“…The application of ALD TiO 2 involves the deposition on different substrates like Ni, Au, and Si to fabricate 3D batteries . Also, amorphous TiO 2 by ALD has been deposited on nanocarbon materials (CNTs and graphene) as an anode in LIBs …”