We have prepared new cathode battery composite, based on graphene and poly(phenanthrene quinone) (rGO/PFQ). It was developed in attempt to increase voltage of Li battery: compared to it's predecesor poly(anthraquinone) we have achieved 400 mV higher voltage. Graphene was added to improve electronic paths and increase porosity of the material. This material exhibit very stable cycling performance with only 9% drop after 500 cycles.
COBISS.SI-ID: 6463770
Organic cathode materials can be used in various battery systems like lithium, sodium, magnesium batteries and can be prepared from low-cost and sustainable resources, which makes them one of the promising materials for future batteries. One of the pressing issues of contemporary research on the cathode materials was the lack of characterization techniques that would allow real-time monitoring of changes inside cathodes during electrochemical cycling. With the financing from the Honda R&D Europe and Slovenian Research agency and joint effort from two departments we developed a new method of probing changes inside the cathodes through IR spectroscopy. Method was developed for explanation of poly (anthraquinonyl) sulfide polymer in Li and Mg batteries. In both systems we observed reduction of carbonyl bond during discharge of the battery. The results of IR measurements were confirmed through calculation of theoretical spectra and synthesis of model compounds. New method presents a powerful tool for research of new organic cathode materials and study of degradation processes inside cathodes. Confirmation of the discharge mechanism in Mg battery system opens new possibilities in research of Mg?organic batteries, where we are successfully cooperating with Honda R&D Europe in the last five years.
COBISS.SI-ID: 6333978
Review article written about state of research on Mg, Ca and Al rechargeable batteries. In the review we also focused on the application of organic cathodes to these battery systems.
COBISS.SI-ID: 6689306
IR spectroscopy can be a non-destructive and straightforward probing tool in the battery research. However, its application has been limited due to the difficulties related to the handling and interpretation of ex situ samples along with the lack of widely applicable in situ and operando cells. Herein, we show a simple, operando ATR-IR two electrode pouch cell with an IR-transmissive silicon window and discuss its advantages and limitations. This setup is applied to the study of the polyanthraquinone (PAQ) reaction mechanism in Li- and Mg-organic batteries. During the reduction/oxidation process of the PAQ, not only the conversion of both C=O groups into C-O– species is observed, but also the formation of an intermediate semiquinone radical anion as an intermediate product. Furthermore, continuous measurement of IR spectra allows visualization of the gradual solid-electrolyte interphase (SEI) buildup on the cathode during cycling.
COBISS.SI-ID: 6689050
In this article redox mechanism of poly(phenanthrene quinone)/graphene cathode material in Li- and Mg- battery was investigated using operando IR spectroscopy. Obtained spectra were explained using IR spectra of chemically prepared model compounds, DFT calculations and they were in a good agreement. During charging and discharging we were able to detect stable anion radical with to distinct IR peaks.
COBISS.SI-ID: 6811674