Search results

(1 - 2 of 2)
Functionalized 2D Materials as Enablers of High Energy and High Power Energy Storage Devices
Title
Functionalized 2D Materials as Enablers of High Energy and High Power Energy Storage Devices
Creator
Radhakrishnan, Sivaviswa
Date
2023
Description
The present Thesis concerns with the synthesis of novel functionalized 2D materials for applications as cathodes in lithium-ion batteries. It...
Show moreThe present Thesis concerns with the synthesis of novel functionalized 2D materials for applications as cathodes in lithium-ion batteries. It further concerns with the role of porosity in these novel cathode materials to achieve simultaneously high energy and power density. Examples of the novel cathode materials synthesized here include several functionalized hexagonal boron nitride (hBN) and graphene (G) species. hBN was functionalized with Li₂C₂O₄, LiBF₄, -OBF₂ groups, NOBF₄, etc. The color of the functionalized hBN species ranges from white through brown to black indicating drastic changes in the band structure of hBN due to functionalization. Functionalized G species include Li₂C₂O₄ and -OBF₃ functionalized ones. Preliminary electrochemical tests were carried out for an initial assessment of the properties of these materials. Additionally, the role of the DOL solvent was also investigated in high power CFx batteries
Show less
High Energy High Power Primary Lithium Batteries with Graphite Fluoride and Functionalized Boron Nitride Cathodes
Title
High Energy High Power Primary Lithium Batteries with Graphite Fluoride and Functionalized Boron Nitride Cathodes
Creator
Huo, Haobin
Date
2022
Description
The present Thesis concerns with the creation of high energy and high power batteries through the utilization of functionalized 2D materials...
Show moreThe present Thesis concerns with the creation of high energy and high power batteries through the utilization of functionalized 2D materials such as graphite fluoride (CFx) and functionalized boron nitride (FBN). The recent literature of Li-CFx batteries brings forward several methods to fabricate high energy and high power batteries. These methods include nano-architecture and porosity design, boron doping, electrolyte additives etc. The resulting batteries are capable to achieve 800-1000 Wh/kg energy density at a power density of 60-70 kW/kg. Our method is capable to achieve the same performance in a much simpler way by the application of a binder that also functions as an effective inhibitor of the growth of LiF crystals. Since LiF is the discharge product of Li-CFx batteries, it typically clogs the pores of the cathode and avoids fast discharge. Methods that increase the power density of Li-CFx batteries typically focus on the amorphization/dissolution of LiF to allow for a fast Li ion diffusion. Our solution using the effective binder appears to be well suited for a scalable production of high energy and high power Li-CFx batteries through a very small modification of existing production lines. Such high energy and high power batteries are needed for the electrification of aircraft such as unmanned aerial vehicles (UAVs), vertical take-off and landing planes (VTOLs), passenger airplanes and pulsed power sources. While Li-CFx batteries are not rechargeable this is not a problem for the above mentioned applications as current rechargeable batteries cannot provide the required energy and power densities.Li-FBN batteries may provide a rechargeable alternative to Li-CFx when fully developed. In the present thesis, we have demonstrated Li-FBN batteries with similar discharge plateaus and approximately half the capacity of Li-CFx batteries. Our Li-FBN batteries are also rechargeable to a much greater extent than Li-CFx.
Show less