Mechanical Engineering MS Thesis Defense by Mr. YuChe Chang
When: Thursday,
July 13, 2023
11:00 AM
-
1:00 PM
Where: > See description for location
Description: Mechanical Engineering MS Thesis Defense by Mr. YuChe Chang
DATE:
July 13, 2023
TIME:
11:00 a.m. - 1:00 p.m.
LOCATION:
SENG-110 (Materials Science Lab)
TOPIC:
Tough Polymer Electrolyte-based Composites for Structural Supercapacitors
ABSTRACT:
This master's thesis explores the development of multifunctional composites that combine energy storage and structural support capabilities, enabling the integration of additional energy storage into existing structures. Previous studies use a two-component electrolyte consisting of epoxy resin and liquid electrolyte, which presents challenges in balancing mechanical performance and energy storage, along with poor electrochemical interfaces. To address these issues, this thesis investigates a single-phase polymer electrolyte where lithium salt is dissolved into a base polymer to enhance multi-functionality.
Poly(lactic) acid is selected as the base polymer, and lithium bis(trifluoromethanesulfonyl)imide is chosen as the salt. The polymer electrolyte is prepared through solution casting, forming a single-phase solid solution confirmed by X-ray diffraction and differential scanning calorimetry. Fourier transform infrared spectroscopy (FTIR) reveals residual solvent (dimethylformamide, DMF) in the as-cast polymer electrolyte samples, which can be removed through further drying. Upon exposure to controlled humidity, the dried samples absorb controlled amounts of water. Electrochemical and mechanical tests are conducted at different stages, demonstrating the hydrated sample's optimized multi-functionality, with notable ionic conductivity of 3.11 μS/cm and excellent toughness of 15.4 MJ/m^3, surpassing the base polymer's performance. This research is the first to demonstrate the possibility of introducing an additional function into the polymer matrix while improving its mechanical properties.
To showcase the potential use of the single-phase tough polymer electrolyte in structural energy storage devices, it is combined with carbon materials to create a thermally processable composite electrode. A structural super capacitor device, consisting of two layers of composite electrodes sandwiching a layer of polymer electrolyte, exhibits an areal capacitance of approximately 10 mF/cm^2.
The outcomes of this research pave the way for a more sustainable and energy-efficient future by harnessing the potential of polymer composites to optimize energy storage while providing vital structural support.
ADVISOR:
Dr. Caiwei Shen, Assistant Professor of Mechanical Engineering, College of Engineering, UMassD
COMMITTEE MEMBERS:
-Dr. Vijaya Chalivendra, Professor of Mechanical Engineering, College of Engineering Director of Graduate Studies, Engineering and Applied Sciences Co-GPD, College of Engineering, UMassD
-Dr. Chen-Lu Yang, Affiliate Professor, College of Engineering, UMassD
Open to the public. All MNE students are encouraged to attend.
For more information, please contact Dr. Caiwei Shen (cshen2@umassd.edu) or Sue Cunha (scunha@umassd.edu).
DATE:
July 13, 2023
TIME:
11:00 a.m. - 1:00 p.m.
LOCATION:
SENG-110 (Materials Science Lab)
TOPIC:
Tough Polymer Electrolyte-based Composites for Structural Supercapacitors
ABSTRACT:
This master's thesis explores the development of multifunctional composites that combine energy storage and structural support capabilities, enabling the integration of additional energy storage into existing structures. Previous studies use a two-component electrolyte consisting of epoxy resin and liquid electrolyte, which presents challenges in balancing mechanical performance and energy storage, along with poor electrochemical interfaces. To address these issues, this thesis investigates a single-phase polymer electrolyte where lithium salt is dissolved into a base polymer to enhance multi-functionality.
Poly(lactic) acid is selected as the base polymer, and lithium bis(trifluoromethanesulfonyl)imide is chosen as the salt. The polymer electrolyte is prepared through solution casting, forming a single-phase solid solution confirmed by X-ray diffraction and differential scanning calorimetry. Fourier transform infrared spectroscopy (FTIR) reveals residual solvent (dimethylformamide, DMF) in the as-cast polymer electrolyte samples, which can be removed through further drying. Upon exposure to controlled humidity, the dried samples absorb controlled amounts of water. Electrochemical and mechanical tests are conducted at different stages, demonstrating the hydrated sample's optimized multi-functionality, with notable ionic conductivity of 3.11 μS/cm and excellent toughness of 15.4 MJ/m^3, surpassing the base polymer's performance. This research is the first to demonstrate the possibility of introducing an additional function into the polymer matrix while improving its mechanical properties.
To showcase the potential use of the single-phase tough polymer electrolyte in structural energy storage devices, it is combined with carbon materials to create a thermally processable composite electrode. A structural super capacitor device, consisting of two layers of composite electrodes sandwiching a layer of polymer electrolyte, exhibits an areal capacitance of approximately 10 mF/cm^2.
The outcomes of this research pave the way for a more sustainable and energy-efficient future by harnessing the potential of polymer composites to optimize energy storage while providing vital structural support.
ADVISOR:
Dr. Caiwei Shen, Assistant Professor of Mechanical Engineering, College of Engineering, UMassD
COMMITTEE MEMBERS:
-Dr. Vijaya Chalivendra, Professor of Mechanical Engineering, College of Engineering Director of Graduate Studies, Engineering and Applied Sciences Co-GPD, College of Engineering, UMassD
-Dr. Chen-Lu Yang, Affiliate Professor, College of Engineering, UMassD
Open to the public. All MNE students are encouraged to attend.
For more information, please contact Dr. Caiwei Shen (cshen2@umassd.edu) or Sue Cunha (scunha@umassd.edu).
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