A composite electrode of graphene/Bi2Te3 for the fabrication of flexible supercapacitors/thermoelectric devices with high output voltage
Por:
Ojeda L., Velazquez-Galvan Y., Gonzalez-Contreras G., Encinas A., Oliva J.
Publicada:
1 ene 2024
Ahead of Print:
1 abr 2024
Resumen:
In this research, supercapacitors (SCs) were made by using a novel H-type architecture and recycled plastics (used as mechanical support for the fabrication of the SC electrodes). The electrochemical tests indicated that SCs made with pure graphene electrodes produced capacitance/energy-density of 222.8 F g-1/31.1 Wh kg-1. After this, one of the graphene electrodes was substituted by a Bi2Te3 (BiTe) electrode, and the capacitance/energy-density increased up to 410.5 F g-1/67.3 Wh kg-1. Thus, the capacitance was enhanced by 84 %. XPS and Raman spectroscopies demonstrated the presence of oxygen vacancies defects as well as Bi0/Bi3+/Bi5+ and Te0/Te2+ species on the SC electrodes, which were responsible for the charge storage by redox reactions. Subsequently, the cellulose separator in the SC made with BiTe was substituted by a copper sheet to form a thermoelectric device. This one produced a maximum output voltage of 116.4 mV and total power of 6.81 µW/cm2 when a temperature gradient of T = 100 K is applied between its electrodes. Such output voltage is one of the highest reported so far for a single device (normally that voltage is obtained with 5–6 devices connected in series). Additionally, the figure of merit (ZT) was calculated for the BiTe electrode and obtained values 2.84–2.92, which are among the highest reported so far for a thermoelectric material. This work demonstrated that flexible SCs/thermoelectric devices can be fabricated on recycled plastics, which reduces their cost. This is important to push their commercialization for wearable applications. © 2024 Elsevier B.V.
Filiaciones:
Ojeda L.:
División de Materiales Avanzados, Instituto Potosino de Investigación Científica y Tecnológica A. C., SLP, San Luis Potosí, 78216, Mexico
Velazquez-Galvan Y.:
Instituto Tecnológico y de Estudios Superiores de Occidente, Periférico Sur Manuel Gómez Morín 8585, Jalisco, Tlaquepaque, 45604, Mexico
Gonzalez-Contreras G.:
CONAHCYT-Coordinación para la Innovación y la Aplicación de la Ciencia y la Tecnología, Universidad Autónoma de San Luis Potosí, San Luis Potosí, 78000, Mexico
Encinas A.:
División de Materiales Avanzados, Instituto Potosino de Investigación Científica y Tecnológica A. C., SLP, San Luis Potosí, 78216, Mexico
Oliva J.:
Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Boulevard Juriquilla 3001, Querétaro, 76230, Mexico
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