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Conducting and redox-based copolymeric materials for energy storage

dc.contributor.authorBettencourt, Katherine Valentina da Silva
dc.contributor.institutionFaculty of Sciences
dc.contributor.institutionDepartment of Chemistry and Biochemistry
dc.contributor.supervisorSemedo, Ana Pimenta da Gama da Silveira Viana
dc.contributor.supervisorCorreia, Jorge Manuel Palma
dc.date.accessioned2026-01-07T16:50:01Z
dc.date.available2026-01-07T16:50:01Z
dc.date.issued2025
dc.descriptionTese de Mestrado, Química, 2025, Universidade de Lisboa, Faculdade de Ciências
dc.description.abstractLithium-ion batteries are every day at the palm of our hands in smartphones, laptops, and watches. However, with their growing demand, environmental repercussions have come to light, creating an urgent need for alternative battery chemistries. Sodium-ion batteries are a promising alternative due to their natural abundance and chemical similarity to lithium. Despite this, Li-ion technology cannot be directly applied to Na-ion systems since the larger sodium ions destabilize crystalline matrices during battery cycles, making it necessary to rethink electrode materials. Organic cathode materials have gained attention for sodium-ion batteries, being flexible, sustainable, and cost-effective. Among them, carbonyl compounds and conducting polymers stand out. Yet, their low energy densities limit their use. To address this, the present work intends to combine both materials to give place to a hybrid coating with improved stability that can be further modified to increase the specific capacity of the material. In this work, dopamine (DA) and 3,4-ethylenedioxythiophene (EDOT) were electropolymerized to combine their distinct functionalities into a copolymer with enhanced properties. PDA offers strong surface adhesion and easy chemical modification, while PEDOT is known for its good conductivity and chemical stability. During this study, the electrosynthesis of a PDA/PEDOT copolymer was explored, testing various applied potentials, electrolytes, and monomer proportions to optimize it as a cathode. The extensive physicochemical characterization of the copolymer supported the successful combination of these materials, with the electroactivity of the film showing the typical pseudocapacity of PEDOT and the quinone/catechol redox of PDA. Techniques such as FTIR, Raman, AFM, ellipsometry, and in-situ UV-vis, alongside electrochemical methods, allowed detailed analysis of the film’s composition, morphology, thickness, and optoelectronic properties. When tested as cathode, the copolymer showed greater stability and specific capacities than PEDOT, retaining 96 % capacity after 1500 cycles, highlighting its potential as a platform for next-generation hybrid organic cathodes.en
dc.formatapplication/pdf
dc.identifier.tid204174163
dc.identifier.urihttp://hdl.handle.net/10400.5/116516
dc.language.isoeng
dc.subjectPolydopamine
dc.subjectPEDOT
dc.subjectConducting Polymers
dc.subjectElectrocopolymerization
dc.subjectSodium-Ion Batteries
dc.titleConducting and redox-based copolymeric materials for energy storageen
dc.typemaster thesis
dspace.entity.typePublication
rcaap.rightsopenAccess

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