UROP Proceedings 2020-21

School of Engineering Department of Mechanical and Aerospace Engineering 170 Polymer Composite Batteries Supervisor: CIUCCI Francesco / MAE Student: YU Tsz Tat / MAE Course: UROP4100, Fall Reducing the thickness of lab-made solid-state polymer electrolyte remains an engineering challenge because of the low mechanical strength of the common polymer materials. Thus, a novel polymer electrolyte was fabricated using thin, porous, and lightweight polytetrafluoroethylene (PTFE) as a mechanical backbone, with infiltration of a dual salt polymer electrolyte using lithium bis(trifluoromethane- sulfonyl)imide (LiTFSI), lithium bis(oxalate)borate (LiBOB), poly(vinylidene fluorideco- hexafluoropropylene) (PVDF-HFP), fluoroethylene carbonate (FEC) and adiponitrile (ADN). The resultant membrane delivered low resistance (2.2 Ω) and a wide electrochemical window (5.0V). The electrolyte was coupled with lithium metal anode and nickel-manganese-cobalt cathode, and the batteries operated at 2 C for over 500 cycles with high capacity (112 mAh/g), high capacity retention (89%), and high coulombic efficiency (99.776%). Polymer Composite Batteries Supervisor: CIUCCI Francesco / MAE Student: YU Tsz Tat / MAE Course: UROP4100, Spring Lithium-ion batteries, especially solid-state batteries, hold great promise in sustainable energy. However, the narrow operational temperature window (-20 ℃ to +55 ℃) is a major problem yet to be resolved, limiting the practical applications of lithium-ion batteries. In this work, an in-situ polymerized gel polymer electrolyte using 1,3-dioxolane (DOL) and LiPF6, with methyl propionate (MP), fluoroethylene carbonate (FEC), and LiTFSI was developed. The resultant gel polymer electrolyte delivered exceptional ionic conductivity of 3.43 mS/cm2 at 20 ℃ and 1.53 mS/cm2 at -30 ℃. The Li|LiFePO4 cell displayed a high specific capacity of 146.7 mAh/g and coulombic efficiency of 99.93%. Moreover, the cell delivered outstanding thermal stability and was capable of operating with long-term stability at -20 °C. Extended Ortho-K Lens for Myopics Supervisor: LAM David Chuen Chun / MAE Student: SEO Minji / AE Course: UROP1100, Spring UROP1000, Summer Over the past decades, the high prevalence of myopia has been recognized especially in Asian countries and this has encouraged ophthalmologists to investigate a feasible solution to reduce the myopia progression. This report proposes a possible means to apply a temporary change in corneal shape while it discusses the overall progress in the project. By specifying the limitations on the initial experimental setup, tools and controlled variables, this report shows the improvement made on the aforementioned factors and their significances. In the coming summer, it is planned to start the data collection for porcine eyes and the animal handling practice for rabbit eyes.

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