Lithium ion electrochemical insertion in vanadium pentoxide/cucurbit[6]uril intercalates

Abstract

Cucurbit [6]uril (CB[6]) and its complex with VO 2+ (CB[6]VO) were intercalated into lamellar vanadium pentoxide in several proportions, generating a series of hybrid pillarised intercalates in the form of xerogel films. These different guests dramatically affect Li + insertion/expulsion from the composites during redox processes. Our results show that CB[6] has little effect or may even impair charge compensation by Li + , while CB[6]VO exerts the opposite effect, enhancing this process when compared to pure vanadium pentoxide. This is clear evidence that CB[6] binds these ions retaining them in the bulk structure, and when the oculi are blocked by VO 2+ ions, the macrocycle acts as a non-coordinating pillar in the structure favoring ion traffic, and charge compensation processes become easier. Specific charge capacities for pure vanadium pentoxide, CB[6] and CB[6]VO intercalates correspond to 158, 168 and 230 mA h g −1 respectively. † Electronic supplementary information (ESI) available: FTIR and TGA analyses, AFM and SEM images, electrochemical data for the 5, 7 and 10% intercalates.

Dynamic supramolecular polymers built from cucurbit[n]urils and viologens

“…CB[ n ]s are also not toxic, cheap and resistant to microorganisms, which makes them excellent candidates to replace cyclodextrins for most applications. Our own contribution to this field includes the stabilization of reactive species and drug carriers, and the use of CB[ n ] as structural elements in hybrid composites, as templates for nanoparticle synthesis, or to develop special catalysts and coatings, sensors and specialty polymers . Their ability to host a wide range of substrates is mainly due to the hydrophobicity of the inner cavity lacking hydrogen bond donor/acceptor moieties.…”

V2O5@ZIF-8 with a Stable Structure and a Fast Ion Diffusion Channel as a Promising Cathode Material for Lithium-Ion Batteries

“…due to the layered structure of V 2 O 5 held together by van der Waals forces. − It can serve as a good host for reversible Li + insertion/extraction; multiple electrons could be captured by V 2 O 5 , and the process could be expressed according to the equation V 2 O 5 + x Li + + x e – ⇔ Li x V 2 O 5. , Unfortunately, the bulk V 2 O 5 in LIBs suffers from poor ion diffusivity (10 –12 cm 2 s –1 ) and low electronic conductivity (10 –4 to 10 –7 S cm –1 ) now, which leads to low discharge capacity density at high discharge current and poor structural stability during long periods of charge and discharge. − …”

Estudo das propriedades eletrônicas e espectroscópicas de uma série de diimidas naftálicas com substituintes aromáticos com potencial aplicação em dispositivos de armazenamento e conversão de energia

“…Estes dados sinalizam uma possível intercalação das diimidas entre as lamelas do óxido 175. Os especros de FTIR (guras 3.46, 3.47 e 3.48) destas amostras demonstram a estrutura do V 2 O 5 com bandas referentes ao estiramento simétrico do fragmento V-O-V em 509 cm −1 , o estiramento assimétrico do fragmento V-O em 762 cm −1 e o modo vibracional da ligação estreita V=O em 1010 cm −1 do tetraedro formado pelo V 2 O 5 112,116,126,130,174,175. Em todos os espectros não há variações nas bandas do óxido demonstrando que a estrutura não foi rompida.…”