Interpenetrated Networks between Graphitic Carbon Infilling and Ultrafine TiO₂ Nanocrystals with Patterned Macroporous Structure for High-Performance Lithium Ion Batteries

Abstract

Interpenetrated networks between graphitic carbon infilling and ultrafine TiO nanocrystals with patterned macropores (100-200 nm) were successfully synthesized. Polypyrrole layer was conformably coated on the primary TiO nanoparticles (∼8 nm) by a photosensitive reaction and was then transformed into carbon infilling in the interparticle mesopores of the TiO nanoparticles. Compared to the carbon/graphene supported TiO nanoparticles or carbon coated TiO nanostructures, the carbon infilling would provide a conductive medium and buffer layer for volume expansion of the encapsulated TiO nanoparticles, thus enhancing conductivity and cycle stability of the C-TiO anode materials for lithium ion batteries (LIBs). In addition, the macropores with diameters of 100-200 nm in the C-TiO anode and the mesopores in carbon infilling could improve electrolyte transportation in the electrodes and shorten the lithium ion diffusion length. The C-TiO electrode can provide a large capacity of 192.8 mA h g after 100 cycles at 200 mA g, which is higher than those of the pure macroporous TiO electrode (144.8 mA h g), C-TiO composite electrode without macroporous structure (128 mA h g), and most of the TiO based electrodes in the literature. Importantly, the C-TiO electrode exhibits a high rate performance and still delivers a high capacity of ∼140 mA h g after 1000 cycles at 1000 mA g (∼5.88 C), suggesting good lithium storage properties of the macroporous C-TiO composites with high capacity, cycle stability, and rate capability. This work would be instructive for designing hierarchical porous TiO based anodes for high-performance LIBs.

Carbon‐Nanoplated CoS@TiO2 Nanofibrous Membrane: An Interface‐Engineered Heterojunction for High‐Efficiency Electrocatalytic Nitrogen Reduction

“…The broad peak in the range of 20–30° is assigned to the (002) plane of amorphous carbon . Figure S5 shows the Raman spectrum of the C@CoS@TiO 2 nanofibrous membrane, in which the peaks at 147, 199, and 630 cm −1 are characteristic of the E g mode, the peak at 385 cm −1 is characteristic of the B 1g mode, and the peak at 511 cm −1 is characteristic of the A 1g mode of TiO 2 . On the other hand, the peak at 675 cm −1 is typical for the A 1g mode of CoS .…”

A Facile One‐Pot Synthesis of Hierarchically Organized Carbon/TiO2 Monoliths with Ordered Mesopores

“…[18][19][20][21][22][23][24][25] Hence, many synthesis strategies have been developed to obtain C/TiO 2 . [13,[26][27][28][29][30][31][32][33][34][35] A common approach towards materials with periodically arranged mesopores is the use of a phenolic resin as carbon source and TiCl 4 or tetraethyl orthotitanate as titanium source in a solution (ethanol/water mixture) with a non-ionic structure directing agent (SDA) (mostly Pluronic F127, but also block copolymers consisting of polyoxyethylene and/or polyoxypropylene units). [13,36] After evaporating the solvent mixture, the resin/titania product is carbonized at various reaction temperatures and for different reaction times.…”

“…However, the formation of C/TiO 2 nanocomposites with ordered mesoporous characteristics remains challenging. [7,33,35,36] In one case, meso-porous TiO 2 was synthesized and infiltrated with a carbon source followed by carbonization. In other cases an in-situ reaction of a phenolic based resin, to which TiCl 4 or Ti(O n Bu) 4 were added as titanium source, was performed in an ethanol/water mixture.…”

A stable TiO2–graphene nanocomposite anode with high rate capability for lithium-ion batteries

“…This was achieved by developing TiO 2 nanotubes, nanowires, and altering the crystal structures of material through high temperature calcination. [9][10][11][12][13][14][15][16][17][18] However, as discussed above the low electrical conductivity of TiO 2 still limits its electrochemical performance for battery application. 19 TiO 2 composites with carbon and metal oxides have demonstrated improvements in electronic conductivity, but more work is required to achieve a material which can be of technical relevance.…”