Electrochemical performance of organic electroactive materials for application in rechargeable batteries

摘要

Rechargeable batteries consisting of organic base electrodes are increasingly being studied as an alternative to conventional inorganic electrodes. The approach adopted in this work involves the development of new cathode organic materials based on polyimide derivatives with significant redox potential or capacity in order to increase stability and improve the energy density of current lithium ion cells. Preparation of organic polymeric polyimides was carried out, followed by their integration in an electrode structure that uses carbon nanofibers, as a support and as a means to increase conductivity. An electrochemical study based on cyclic voltammetry was conducted in order to evaluate the performance and redox capacity of the electrodes. The implemented strategy is based on the fact that the aromatic imide group may be electrochemically reduced and oxidized in a reversible manner, with each molecule of polyimide being able to transfer four electrons in two steps, accounting for a high specific capacity of the electrodes. Some of the composite electrodes studied in this work demonstrated good redox capacity, stability under potential cycling and higher current densities, 10-20X, than those reported in the literatures for similar compounds.