Mecanismos reacionais dos sistemas Pb/H2SO4 e Pb/PbO2/H2SO4

Abstract

The thesis will address a modern view of electrochemistry for the discharge and charge reactions of Lead Acid Batteries study. Even though these batteries have existed for more than 200 years, electrochemical mechanisms are still not fully understood. Recently, there is a discussion in Brazil about the need to improve energy accumulation processes that have not kept pace with the development of technologies such as electric car engines, telephony devices, computers. The production of lead-acid batteries is the only Brazilian energy accumulator. These Batteries continue to grow worldwide, increasing their forms of use, leaving the current car starter batteries and stationary stabilizers for hybrid cars (micro and medium hybrid), electric motorcycles, electric trains, mobile phone towers, oil platforms, among others. In this thesis, we started a critical review of the published data bibliography and its meanings. Most of the published work proposes that the mechanisms of unloading and loading the plates are by dissolving precipitation and would be similar. However, studies with negative and positive flat electrodes show almost no dissolution during these electrochemical reactions. Thus, the precipitation dissolution mechanism would not be justified. In the last decades, several studies already indicate that these mechanisms can be understood as solid-state mechanisms by adding the partial disruption phenomenon, which we will explore in this thesis. The literature data shows differences between the negative and positive plates mechanisms that need modern treatments because their discharge products are different films and from nanometer order. Finally, electrochemical and analytical studies will be carried out, with positive and negative flat electrodes. Experimental methods for negative flat electrodes are treated in detail, while positive flat electrodes still have a lot to be developed.