NANOSTRUCTURED THIN FILM POLYMER ELECTROLYTES FOR FLEXIBLE BATTERY APPLICATIONS

dc.contributor.advisorKofinas, Peteren_US
dc.contributor.authorGhosh, Ayanen_US
dc.contributor.departmentChemical Engineeringen_US
dc.contributor.publisherDigital Repository at the University of Marylanden_US
dc.contributor.publisherUniversity of Maryland (College Park, Md.)en_US
dc.date.accessioned2010-07-02T05:32:54Z
dc.date.available2010-07-02T05:32:54Z
dc.date.issued2009en_US
dc.description.abstractIn recent years, the interest in polymeric batteries has increased dramatically. With the advent of lithium ion batteries being used in cell phones and laptop computers, the search for an all solid state battery has continued. Current configurations have a liquid or gel electrolyte along with a separator between the anode and cathode. This leads to problems with electrolyte loss and decreased performance over time. The highly reactive nature of these electrolytes necessitates the use of protective enclosures which add to the size and bulk of the battery. Polymer electrolytes are more compliant than conventional inorganic glass or ceramic electrolytes. The goal of this work was to design and investigate novel nanoscale polymer electrolyte flexible thin films based on the self-assembly of block copolymers. Block copolymers were synthesized, consisting of a larger PEO block and a smaller block consisting of random copolymer of methyl methacrylate (MMA) and the lithium salt of methacrylic acid (MAALi). The diblock copolymer [PEO-b-(PMMA-ran-PMAALi)] with added lithium bis(oxalato)borate, LiBC<sub>4</sub>O<sub>8</sub> (LiBOB) salt (in the molar ratio ethylene oxide:LiBOB = 3:1) was used to form flexible translucent films which exhibited nearly two orders of magnitude greater conductivity than that shown by traditional high molecular weight PEO homopolymer electrolytes, in the absence of ceramic fillers and similar additives. The presence of the smaller second block and the plasticizing effect of the bulky lithium salt were shown to effectively reduce the crystallinity of the solid electrolyte, resulting in improved ion transporting behavior. The tailored solid self-assembled diblock copolymer electrolyte matrix also exhibits an exceptionally high lithium-ion transference number of 0.9, compared to a value between 0.2 and 0.5, shown by typical polymer-lithium salt materials. The electrolyte material also has a wide electrochemical stability window and excellent interfacial behavior with lithium metal electrode. The combination of these properties make electrolyte membranes composed of the diblock copolymer PEO-b-(PMMA-ran-PMAALi) and LiBOB salt, viable electrolyte candidates for flexible lithium ion based energy conversion/storage devices.en_US
dc.identifier.urihttp://hdl.handle.net/1903/10224
dc.subject.pqcontrolledEngineering, Chemicalen_US
dc.subject.pqcontrolledEngineering, Materials Scienceen_US
dc.subject.pqcontrolledEnergyen_US
dc.subject.pquncontrolledBlock Copolymersen_US
dc.subject.pquncontrolledLithium-ion batteriesen_US
dc.subject.pquncontrolledPolymer Electrolyteen_US
dc.titleNANOSTRUCTURED THIN FILM POLYMER ELECTROLYTES FOR FLEXIBLE BATTERY APPLICATIONSen_US
dc.typeDissertationen_US

Files

Original bundle
Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
Ghosh_umd_0117E_11036.pdf
Size:
52.61 MB
Format:
Adobe Portable Document Format