Resumo em português Esta revisão visa ser uma introdução à aplicação de materiais cerâmicos em dispositivos de armazenamento de energia, em especial baterias secundárias de íons lítio, dispositivos nos quais os materiais cerâmicos, especialmente óxidos, são muito importantes em todas as partes do dispositivo. A revisão está focada nos materiais cerâmicos para catodos e anodos, partes chaves destes dispositivos. Ela tem por principal finalidade ser uma fonte de informação pa (mais) ra aqueles que desejem trabalhar com o desenvolvimento de materiais cerâmicos para tais tipos de dispositivos. Aspectos relacionados à nanotecnologia e materiais óxidos nanoestruturados para esta área são discutidos ao final do artigo. Resumo em inglês This paper aims to be an introductory text on the applications of ceramic materials to energy storage devices, mainly lithium ion secondary batteries, i.e. devices in which the ceramic materials, e.g. oxides, are very important in all parts of the device. This review is focused in ceramic materials for cathodes and anodes, which are key parts of the battery device. The main purpose is, therefore, to offer to the reader, who is interested in the development of ceramic mate (mais) rials for storage devices, enough information concerning the main oxide materials used nowadays and promising technology regarding nanoestructured oxides and electrode geometry based on the nanoscale.
Resumo em inglês In this work, composites formed from a mixture of V2O5 and polyaniline (PANI) were investigated, for applications as cathode materials for secondary lithium batteries. Electrochemical quartz crystal microbalance (EQCM) data show that charge compensation in the [PANI]0.3V2O5 nanocomposite is achieved predominantly by Li+ migration. However, the charge compensation in the [PANI]V2O5 microcomposite occurs by Li+ and ClO4- transport. Electrochemical Impedance Spectroscopy (EI (mais) S) measurements reveal several benefits of nanohybrid formation, including the achievement of shorter ionic diffusion pathways, the higher diffusion rate of the lithium ion and also the higher electronic conductivity, which are responsible for a synergetic effect of the energy storage properties.
Resumo em inglês This paper presents the alkaline battery (MnO2/Zn) as a useful device in the teaching of chemistry. The preparation of the battery, the materials used in the preparation of the MnO2 electrode, the mechanism of energy storage and the parameters often used in the understanding of general batteries are discussed in detail. In addition, a schedule and a questionnaire that can be applied in an experimental class have been developed, which allow the assembly of an alkaline batt (mais) ery, its discharge using a galvanostatic or a load-resistance procedure, and the elaboration of a report based on the main text. This experimental class has been offered in the chemistry course of FFCLRP.
Resumo em inglês Nickel metal hydride (Ni-MH) batteries have emerged as an alternative for replacement of nickel-cadmium batteries, because of their more environmental compatibility and high energy capacity. In this article, we described the properties and applications for Ni-MH batteries, giving some emphasis on the metal-hydride electrode, including the description of composition, the charge storage capacity and the discharge profile. The key component of the nickel-metal hydride electr (mais) ode is a hydrogen storage alloy whose composition is formulated to obtain a high stable material over a large number of charge-discharge cycles.