Tuning the Defects of Two-Dimensional Layered Carbon/TiO2 Superlattice Composite for a Fast Lithium-Ion Storage

Abstract

Defect engineering is one of the effective ways to improve the electrochemical property of electrode materials for lithium-ion batteries (LIB). Herein, an organic functional molecule of p-phenylenediamine is embedded into two-dimensional (2D) layered TiO2 as the electrode for LIB. Then, the 2D carbon/TiO2 composites with the tuning defects are prepared by precise control of the polymerization and carbothermal atmospheres. Low valence titanium in metal oxide and nitrogen-doped carbon nanosheets can be obtained in the carbon/TiO2 composite under a carbonization treatment atmosphere of N2/H2 gas, which can not only increase the electronic conductivity of the material but also provide sufficient electrochemical active sites, thus producing an excellent rate capability and long-term cycle stability. The prepared composite can provide a high capacity of 396.0 mAh g−1 at a current density of 0.1 A g−1 with a high capacitive capacity ratio. Moreover, a high specific capacity of 80.0 mAh g−1 with retention rate of 85% remains after 10,000 cycles at 3.0 A g−1 as well as the Coulomb efficiency close to 100%. The good rate-capability and cycle-sustainability of the layered materials are ascribed to the increase of conductivity, the lithium-ion transport channel, and interfacial capacitance due to the multi-defect sites in the layered composite.

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

“…This can promote the vertical diffusion of K ions and provide sufficient electrochemical active sites, leading to a high specific capacity. [ 39 ] However, the increased surface disorder of the MOF‐NOC@L‐TiO 2 inevitably leads to a decline in conductivity. Hence, the highest capacity can be achieved with just a moderate number of defects.…”

Designing High‐mass Loading 2D Ni‐TiO2/graphene Pellet Electrodes for Lithium Metal Batteries

“…However, the electronic conductivity of the pellet did not rise in tandem with the further increased pPDA ratio, indicating that the conductivity of NTO/Gr is higher than that of carbonized pPDA at 500 °C. [52] Meanwhile, we assembled coin cells for electrochemical performance comparison. Figure S7c depicts the rate curves of NTO/Gr + PA%, and we can determine that NTO/Gr-1PA has the best rate performance and the highest specific capacity.…”

Two-dimensional layered lithium lanthanum titanium oxide/graphene-like composites as electrodes for lithium-ion batteries

“…It can be shown that LLTO@C-500/600 contain a high content of graphene nanosheets after the carbonization reaction. Besides, the electronic conductivity test of the layered LLTO@C composites was carried out according to our previous work by using a two-electrode blocked cell within a voltage range from −0.2 to 0.2 V, 34 which can explain the improved electrical conductivity of the 2D nanosheets which is highly beneficial for the rapid electronic transportation and power delivery. According to the conductivity formula: σ (S m −1 ) = L / RS , where S (m 2 ) is the cross-sectional area, R (Ω) is the resistance value and L (m) is the length.…”