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dc.contributor.advisorYu, Guihua (Assistant professor)
dc.creatorShi, Ye, Ph. D.
dc.date.accessioned2017-07-11T22:27:28Z
dc.date.available2017-07-11T22:27:28Z
dc.date.issued2017-05
dc.date.submittedMay 2017
dc.identifierdoi:10.15781/T2KK94T01
dc.identifier.urihttp://hdl.handle.net/2152/60387
dc.description.abstractThis work presents the rational design and synthesis of conductive polymer gels (CPGs) using doping molecules as crosslinkers. Molecules with multiple functional groups are used to crosslink the conductive polymer chains, leading to CPGs with 3D networked structures. These dopant molecules crosslinked CPGs exhibit both high electrical and ionic conductivities since they construct heavily doped and interconnected polymer network for electron transport and hierarchically porous structure for ion diffusion. The chemical and physical properties of dopant molecules crosslinked CPGs can be facilely tuned by controlling the dopants and synthetic conditions. With improved electrochemical properties, CPGs have been applied as an electrode material in supercapacitors and as a binder material in lithium ion batteries. CPGs establish a continuous network to promote the transport of electrons, provide short ion diffusion path and large surface area for redox reactions, and construct a porous architecture with intrinsic elasticity to accommodate the volume change, thus showing high capacitance and rate capability as supercapacitor electrode materials. High elasticity derived by the structure of CPGs further enables highly flexible supercapacitor. CPGs were also adopted as bifunctional binder materials for lithium ion battery electrodes, acting as both polymeric binder and a conductive additive. The gel framework based electrode exhibits greatly improved rate and cyclic performance owing to improved electronic and ionic transport. In addition, both inorganic and organic components are uniformly distributed within the electrode due to the polymer coating. The robust framework further provides mechanical strength to support active electrode materials and improves the long-term electrochemical stability. Combined with other functional gels, CPGs have been also adopted for smart electrochemical devices. Based on CPGs and a thermoresponsive electrolyte system, electrochemical energy storage devices with thermal self-protection behavior are developed. The smart electrolyte system is achieved by employing a commercially available thermoplastic elastomer, Pluronic, which shows a fast sol-gel transition process upon heating. The gelation of Pluronic solution based electrolytes significantly inhibits the migration of ions, leading to a nearly 100% decrease in specific capacitance. The responsive behavior is highly reversible and tunable. Various electrode materials and conductive ions are compatible with this system. Finally, multifunctional hybrid gel materials based on CPGs are developed by introducing a second responsive polymeric network, forming an interpenetrating double network structure. A highly thermoresponsive and conductive hybrid gel is synthesized by in situ polymerization of CPGs within PNIPAM matrix and a room-temperature self-healing hybrid gel is prepared by introducing a supramolecular gel into PPy gel framework.
dc.format.mimetypeapplication/pdf
dc.language.isoen
dc.subjectConductive polymer gel
dc.subjectResponsive electronics
dc.subjectElectrochemical energy storage
dc.titleRational design of 3D nanostructured conductive polymer gels for electrochemical energy storage and responsive electronic devices
dc.typeThesis
dc.date.updated2017-07-11T22:27:29Z
dc.contributor.committeeMemberEllison, Christopher J.
dc.contributor.committeeMemberLu, Nanshu
dc.contributor.committeeMemberLi, Wei
dc.description.departmentMaterials Science and Engineering
thesis.degree.departmentMaterials Science and Engineering
thesis.degree.disciplineMaterials Science & Engineering
thesis.degree.grantorThe University of Texas at Austin
thesis.degree.levelDoctoral
thesis.degree.nameDoctor of Philosophy
dc.type.materialtext


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