Preparation of Brookite‐Type TiO<sub>2</sub>/Carbon Nanocomposite Electrodes for Application to Li Ion Batteries

Lee, Du-Hee; Park, Jae–Gwan; Choi, Kyoung Jin; Choi, Heon‐Jin; Kim, Dong-Wan

doi:10.1002/ejic.200700943

Cited by 78 publications

(32 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Further studies revealed that the reversibility of Li insertion decreased with an increase in crystallite size of brookite [126]. Hybrid multi-walled carbon nanotube/brookite electrodes improved the specific capacity and capacity retention on cycling [127,128]. Dambournet et al [63] prepared micrometer-size mesoporous brookite electrodes with a high specific area that provided higher volumetric energy density in a lithium ion battery than anatase or rutile electrodes.…”

Section: Pure Brookitementioning

confidence: 99%

Brookite, the Least Known TiO2 Photocatalyst

2013

View full text Add to dashboard Cite

Abstract:Brookite is the least studied TiO 2 photocatalyst due to the difficulties usually encountered in order to obtain it as a pure phase. In this review, a comprehensive survey of the different methods available for preparing brookite powders and films is reported. Attention has been paid both to the most traditional methods, such as hydrothermal processes at high temperatures and pressures, and to environmentally benign syntheses using water soluble compounds and water as the solvent. Papers reporting the photocatalytic activity of pure and brookite-based samples have been reviewed.

show abstract

Section: Pure Brookitementioning

confidence: 99%

Brookite, the Least Known TiO2 Photocatalyst

2013

View full text Add to dashboard Cite

show abstract

“…[37]. Another pair of broad peaks (at 1.45 and 1.75 V) associated with differing site occupations might be attributed to the formation of the discrete phase or imperfection of the TiO 2 lattice, which facilitate the transport of Li through surface defects and in bulk materials [16]. The content of TiO 2 is low and carbon shell is the dominant phase in sample #1.…”

Section: Resultsmentioning

confidence: 99%

“…To address the negative issues, TiO 2 in various nanocrystalline forms are widely used to reduce the diffusion path length for lithium-ions and increase high contact area between electrolyte and electrode, thereby improving both storage capacity and rate capability [11][12][13]. Another common strategy involves incorporation of TiO 2 with carbonaceous materials, which can enhance the electronic conductivity and suppress the aggregation of TiO 2 nanocrystals, thus increasing the anode stability during cycling [14][15][16]. Consequently, TiO 2 @carbon nanocomposite is considered as a promising high-performance anode material in LIBs, and several synthesis methods have been developed.…”

Section: Introductionmentioning

confidence: 99%

Low-temperature one-step solid-phase synthesis of carbon-encapsulated TiO2 nanocrystals as anode materials for lithium-ion batteries

Liu

Shao

Xiang

et al. 2017

Ionics

View full text Add to dashboard Cite

A simple and highly efficient method is developed for in situ one-step preparation of carbon co-encapsulated anatase and rutile TiO 2 nanocrystals (TiO 2 @C) with core-shell structure for lithium-ion battery anode. The synthesis is depending on the solid-phase reaction of titanocene dichloride with ammonium persulfate in an autoclave at 200°C for 30 min. The other three titanocene complexes including bis(cyclopentadienyl)dicarbonyl titanium, cyclopentadienyltitanium trichloride, and cyclopentadienyl(cycloheptatrienyl)titanium are used instead to comprehensively investigate the formation mechanism and to improve the microstructure of the product. The huge heat generated during the explosive reaction cleaves the cyclopentadiene ligands into small carbon fragments, which form carbon shell after oxidative dehydrogenation coating on the TiO 2 nanocrystals, resulting in the formation of core-shell structure. The TiO 2 nanocrystals prepared by titanocene dichloride have an equiaxed morphology with a small diameter of 10-55 nm and the median size is 30.3 nm. Hundreds of TiO 2 nanocrystals are encapsulated together by the worm-like carbon shell, which is amorphous and about 20-30 nm in thickness. The content of TiO 2 nanocrystals in the nanocomposite is about 31.1 wt.%. This TiO 2 @C anode shows stable cyclability and retains a good reversible capacity of 400 mAh g −1 after 100 cycles at a current density of about 100 mA g −1, owing to the enhanced conductivity and protection of carbon shell.

show abstract

“…This technique was based on that of Pottier, et al [84] which yielded similar particle size and morphology. In a separate study, Lee, et al [85] dissolved urea in an aqueous solution containing titanium trichloride (TiCl 3 ), and refluxed the solution at 100°C for 7 hours. This process produced large aggregates of nanospherical, 10-20 nm crystallites.…”

Section: Brookitementioning

confidence: 99%

“…They made electrodes by mixing brookite active material with acetylene black and PVDF in a weight ratio of 70:20:10, and were able to achieve a reversible capacity of 170 mA h g −1 over 40 cycles at a 35 mA g −1 (corresponding to a rate of C/10; 1 Li in 10 hours). Lee, et al [85] compared pristine brookite (mixed with super P and PVDF in a ration of 68:20:12) and composites of brookite with multi walled carbon nanotubes (MWCNT) using the same binder ratio, but replacing super P with composite active material. At C/5 rate (in this case corresponding to 0.5 Li in 5 hours), reversible capacity of 160 mA h g −1 was achieved over 50 cycles.…”

Section: Brookitementioning

confidence: 99%

Novel Mesoporous Nanotitania/Carbon Composite Electrodes for Electrochemical Energy Storage

et al. 2013

View full text Add to dashboard Cite

The development of novel scalable nanoscale materials and fabrication techniques for high performance TiO 2 Li-ion electrodes is investigated in this thesis. The development and study of the novel fabrication methods is approached from the stand point of a binder-free electrode, and its comparison to standard binder-based electrodes, making use of commercial P25 TiO 2 product as active material. The characterization of novel titania synthesized by manipulating the parameters of an aqueous process, is performed for two phases of TiO 2 , namely anatase and brookite, based on comprehensive nanocrystal morphological and electrochemical property assessment. Finally all is brought together by investigating the application of the novel fabrication protocol to the aqueous synthesized anatase to engineer binderfree 3-dimensional electrodes, and studying their Li-ion intercalation performance.The fabrication of binder-free P25 nanotitania/carbon composite electrodes is pursued via formulating pastes and controlled sintering yielding enhanced electrochemical performance in comparison to standard binder-based methods using the same active and conductive components. The new paste formulation and sintering sequence provides a significant increase in dispersion of carbon due to smaller agglomerate size resulting in enhanced inter-particle (active-conduction) mixing and packing density than standard binder-based electrodes. Cyclic voltammetry and galvanostatic charge/discharge proved that the binder-free electrodes possess improved conductivity, specific capacity, and reversibility, as compared to binderbased electrodes. Most significantly, the capacity retention of the binder-free electrode was much higher than that of the binder-based electrode at 94 and 53%, respectively.iii Using an aqueous solution based synthesis process, 2-dimensional brookite nanoplatelets and 6 nm anatase nanoparticles are obtained and examined for their physical and electrochemical properties as Li-ion host materials. Brookite, itself is particularly interesting, as it is the least understood of the nanoscale TiO 2 phases, especially in the form of 2-D crystal structures that are deemed advantageous for Liion diffusion. This study provides insight into the lithiation mechanism of brookite, concluding that a solid-solution is formed upon lithiation corresponding to Li 0.5 TiO 2 that is isostructural with brookite. Further, the brookite nanoplatelets are discovered to undergo unique crystal structure enhancement upon cycling that allows them to quickly relax upon delithiation in an extremely efficient (>99.7% Coulombic efficiency) reversible manner translating to excellent Li-ion intercalation stability.Anatase nanoparticle are described in terms of crystallinity and surface area. Asprepared anatase has low crystallinity (∼70%), but high surface area (∼222 m 2 g −1 ), and when annealed at 300°C, the crystallinity increases to ∼90% but the surface area drops to 120 m 2 g −1 . Electrochemically, this allows the annealed sample with higher crystall...

show abstract

Preparation of Brookite‐Type TiO₂/Carbon Nanocomposite Electrodes for Application to Li Ion Batteries

Cited by 78 publications

References 31 publications

Brookite, the Least Known TiO2 Photocatalyst

Brookite, the Least Known TiO2 Photocatalyst

Low-temperature one-step solid-phase synthesis of carbon-encapsulated TiO2 nanocrystals as anode materials for lithium-ion batteries

Novel Mesoporous Nanotitania/Carbon Composite Electrodes for Electrochemical Energy Storage

Contact Info

Product

Resources

About

Preparation of Brookite‐Type TiO2/Carbon Nanocomposite Electrodes for Application to Li Ion Batteries

Cited by 78 publications

References 31 publications

Brookite, the Least Known TiO2 Photocatalyst

Brookite, the Least Known TiO2 Photocatalyst

Low-temperature one-step solid-phase synthesis of carbon-encapsulated TiO2 nanocrystals as anode materials for lithium-ion batteries

Novel Mesoporous Nanotitania/Carbon Composite Electrodes for Electrochemical Energy Storage

Contact Info

Product

Resources

About

Preparation of Brookite‐Type TiO₂/Carbon Nanocomposite Electrodes for Application to Li Ion Batteries