Publicação
Sustainable fiber-based structures for application in electronic and electrochemical systems
| Resumo: | The main goal of this PhD project was to develop fiber-based energy storage devices, commonly also known as textile-based electrochemical energy storage devices (TEESDs), namely supercapacitors (SCs). By incorporating sustainable processes and materials, two main architectures of fiber-based 1D and 2D, were explored and integrated into textiles. The developed 1D fiber-shaped supercapacitors (FSCs) combine stretch-broken carbon fiber yarns (SBCFYs) as both current collector and active material, paired with an in-situ regenerated cellu-lose-based ionic hydrogel (RCIHs) as electrolyte. The SBCFYs and cellulose can be recovered for reuse, allowing the fabrication of new 1D FSCs without significant loss in electrochemical performance, even after 2 years and 5 months, owing to the hydrophilic nature of cellulose and stability of the SBCFYs. The hybridization of SBCFYs was further explored with V2O5, MnO2 and MoS2 as active mate-rials with a particular focus on MoS2. Hydrothermal synthesis using conventional- and microwave-as-sisted heating (CAH, MAH) was conducted. MAH hybridized SBCFYs demonstrate 95.7 % capacitance retention after 3000 cyclic voltammetry (CV) cycles. Moreover, both hybridized SBCFYs displayed capacitive behavior even after 60 days of being synthesized through both approaches. The 2D architecture was explored by utilizing screen-printing with commercially available inks, including silver, carbon, and PEDOT:PSS, as current collectors and active materials. An impregnated cotton fabric with cornstarch-based electrolyte (CotCSBE) was applied, providing an adhesive and ro-bust interface between the symmetric parts of the device. The influence of the number of PEDOT:PSS printed layers on devices performance was investigated, achieving capacitances of 5.51±0.44 mF·cm-2 at 5 mV·s-1, with 81.93 % retention after 10,000 galvanostatic charge-discharge (GCD) cycles for four layers. The potential of using reduced graphene oxide (rGO) and laser induced graphene (LIG) as both current collectors and active materials in the 2D architecture was also considered. The fabricated 1D and 2D SCs exhibited versatility on different prototypes. Six woven FSCs connected in series light up three red LEDs. Additionally, five FSCs, hybridized via MAH, connected in series and hand-stitched onto a cotton fabric, demonstrated their ability to power a humidity and temperature sensor for up to 6 minutes. Six printed and textile-based 2D SCs, also connected in series, continually powered a watch for 1 hour. |
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| Autores principais: | Carvalho, José Tiago Macedo de |
| Assunto: | supercapacitors cellulose cornstarch carbon fibers MoS2 PEDOT:PSS |
| Ano: | 2023 |
| País: | Portugal |
| Tipo de documento: | tese de doutoramento |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade Nova de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório Institucional da UNL |
| Resumo: | The main goal of this PhD project was to develop fiber-based energy storage devices, commonly also known as textile-based electrochemical energy storage devices (TEESDs), namely supercapacitors (SCs). By incorporating sustainable processes and materials, two main architectures of fiber-based 1D and 2D, were explored and integrated into textiles. The developed 1D fiber-shaped supercapacitors (FSCs) combine stretch-broken carbon fiber yarns (SBCFYs) as both current collector and active material, paired with an in-situ regenerated cellu-lose-based ionic hydrogel (RCIHs) as electrolyte. The SBCFYs and cellulose can be recovered for reuse, allowing the fabrication of new 1D FSCs without significant loss in electrochemical performance, even after 2 years and 5 months, owing to the hydrophilic nature of cellulose and stability of the SBCFYs. The hybridization of SBCFYs was further explored with V2O5, MnO2 and MoS2 as active mate-rials with a particular focus on MoS2. Hydrothermal synthesis using conventional- and microwave-as-sisted heating (CAH, MAH) was conducted. MAH hybridized SBCFYs demonstrate 95.7 % capacitance retention after 3000 cyclic voltammetry (CV) cycles. Moreover, both hybridized SBCFYs displayed capacitive behavior even after 60 days of being synthesized through both approaches. The 2D architecture was explored by utilizing screen-printing with commercially available inks, including silver, carbon, and PEDOT:PSS, as current collectors and active materials. An impregnated cotton fabric with cornstarch-based electrolyte (CotCSBE) was applied, providing an adhesive and ro-bust interface between the symmetric parts of the device. The influence of the number of PEDOT:PSS printed layers on devices performance was investigated, achieving capacitances of 5.51±0.44 mF·cm-2 at 5 mV·s-1, with 81.93 % retention after 10,000 galvanostatic charge-discharge (GCD) cycles for four layers. The potential of using reduced graphene oxide (rGO) and laser induced graphene (LIG) as both current collectors and active materials in the 2D architecture was also considered. The fabricated 1D and 2D SCs exhibited versatility on different prototypes. Six woven FSCs connected in series light up three red LEDs. Additionally, five FSCs, hybridized via MAH, connected in series and hand-stitched onto a cotton fabric, demonstrated their ability to power a humidity and temperature sensor for up to 6 minutes. Six printed and textile-based 2D SCs, also connected in series, continually powered a watch for 1 hour. |
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