title: Effects of self-assembled materials prepared from V2O5 for lithium ion electroinsertion.
abstract: Self-assembled materials consisting of V(2)O(5), polyallylamine (PAH) and silver nanoparticles (AgNPs) were obtained by the layer-by-layer (LbL) method, aiming at their application as electrodes for lithium-ion batteries and electrochromic devices. The method employed herein allowed for linear growth of visually homogeneous films composed of V(2)O(5), V(2)O(5)/PAH, and V(2)O(5)/PAH/AgNP with 15 bilayers. According to the Fourier transform infrared spectra, interaction between the oxygen atom of the vanadyl group and the amino group should be responsible for the growth of these films. This interaction also enabled establishment of an electrostatic shield between the lithium ions and the sites with higher negative charge, thereby raising the ionic mobility and consequently increasing the energy storage capacity and reducing the response time. According to the site-saturation model and the electrochemical and spectroelectrochemical results, the presence of PAH in the self-assembled host matrix decreased the number of V(2)O(5) electroactive sites. Thus, AgNPs were stabilized in PAH and inserted into the nanoarchitecture, so as to enhance the specific capacity. This should provide new conducting pathways and connect isolated V(2)O(5) particles in the host matrix. Therefore, new nanoarchitectures for specific interactions were formed spontaneously and chosen as examples in this work, aiming to demonstrate the potentiality of the adopted self-assembled method for enhancing the charge transport rate into the host matrices. The obtained materials displayed suitable properties for use as electrodes in lithium batteries and electrochromic devices.
authors.affiliation: Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-901 Ribeirão Preto (SP), Brazil.
authors.forename: Nelson A
authors.initials: NA
authors.lastname: Galiote
authors.forename: Maiuí N L
authors.initials: MN
authors.lastname: Camargo
authors.forename: Rodrigo M
authors.initials: RM
authors.lastname: Iost
authors.forename: Frank
authors.initials: F
authors.lastname: Crespilho
authors.forename: Fritz
authors.initials: F
authors.lastname: Huguenin
mesh_terms: D011211:Electric Power Supplies; D055664:Electrochemical Techniques; D004566:Electrodes; D007477:Ions / Q000737:chemistry; D008094:Lithium / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry; D010316:Particle Size; D011073:Polyamines / Q000737:chemistry; D012834:Silver / Q000737:chemistry; D013499:Surface Properties; D017968:Vanadium Compounds
chemical_list: D007477:Ions; D011073:Polyamines; D017968:Vanadium Compounds; C063994:polyallylamine; D012834:Silver; D008094:Lithium; C066075:vanadium pentoxide