Lithium ion batteries are receiving considerable attention in applications, ranging from portable electronics to electric vehicles, due to their superior energy density over other rechargeable battery technologies. However, the societal demands for lighter, thinner, and higher capacity lithium ion batteries necessitate ongoing research for novel materials with improved properties over that of stateof-the-art. Such an effort requires a concerted development of both electrodes and electrolyte to improve battery capacity, cycle life, and charge-discharge rates while maintaining the highest degree of safety available. Carbon nanotubes (CNTs) are a candidate material for use in lithium ion batteries due to their unique set of electrochemical and mechanical properties. The incorporation of CNTs as a conductive additive at a lower weight loading than conventional carbons, like carbon black and graphite, presents a more effective strategy to establish an electrical percolation network. In addition, CNTs have the capability to be assembled into free-standing electrodes (absent of any binder or current collector) as an active lithium ion storage material or as a physical support for ultra high capacity anode materials like silicon or germanium. The measured reversible lithium ion capacities for CNT-based anodes can exceed 1000 mAh g À1 depending on experimental factors, which is a 3Â improvement over conventional graphite anodes. The major advantage from utilizing free-standing CNT anodes is the removal of the copper current collectors which can translate into an increase in specific energy density by more than 50% for the overall battery design. However, a developmental effort needs to overcome current research challenges including the first cycle charge loss and paper crystallinity for free-standing CNT electrodes. Efforts to utilize pre-lithiation methods and modification of the single wall carbon nanotube bundling are expected to increase the energy density of future CNT batteries. Other progress may be achieved using open-ended structures and enriched chiral fractions of semiconducting or metallic chiralities that are potentially able to improve capacity and electrical transport in CNT-based lithium ion batteries. Lithium ion batteriesThe need to have better energy storage for technological applications like consumer electronics, hybrid-electric-vehicles, and remote sensing applications is propelling electrochemical devices to the forefront of research goals. 1,2 In particular, battery

A method of purity assessment for multi-walled carbon nanotubes (MWNTs) using Raman spectroscopy has been developed. Reference sample sets were constructed using MWNTs, synthesized by injection chemical vapor deposition (CVD), and carbon impurities (i.e. carbon soot and nanostructured carbon). Raman spectroscopy was performed and ratios of the characteristic peaks were measured (i.e. I D /I G , I G' /I G , and I G' /I D). Different vibrational modes in the various carbon species give rise to these peaks and result in characteristic Raman spectra for MWNTs and carbon impurities. Calibration curves were constructed from the reference sample sets. These calibration curves were used to evaluate MWNTs synthesized under varying experimental conditions (i.e. temperature of 650-950 o C, gas flow rate of 0.5-1.75 L/min, precursor injection rate of 1.5-4 .5 mL/hr, and precursor concentration of 0.04-0.1 M) to determine their 'purity'. The limits associated with this method are discussed in relation to other qualitative and potentially quantitative methods of determining MWNT purity.

Stable dispersions of both as-produced (raw soot) and purified laser-generated single-wall carbon nanotubes (SWNTs) have been demonstrated with several alkyl amide solvents. Optical absorption analysis over a range of concentrations has been utilized to estimate the dispersion limits for as-produced SWNTs in N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMA), N,N-diethylacetamide (DEA), and N,N-dimethylpropanamide (DMP). In addition, extinction coefficients have been calculated using Beer's law for each solvent at energies of 1.27 and 1.77 eV, corresponding to the electronic transitions of semiconducting and metallic SWNTs, respectively. The results imply that high polarizability and optimal geometries (appropriate bond lengths and bond angles) may account for the favorable interaction between SWNTs and the alkyl amide solvents. The successful dispersion of purified SWNTs in DMA has enabled extinction coefficients of 43.4 and 39.0 mL·mg-1·cm-1 to be calculated at the selected energies, respectively. The magnitude of the dispersion limit and extinction coefficient values has been shown to be strongly dependent on the SWNT sample purity. These findings offer the potential for solution-phase analysis of SWNTs directed at purity assessment and electrophoretic separations in a simple organic solvent.

Stabilized lithium metal powder (SLMP) has been applied during battery assembly to effectively prelithiate high capacity (1500-2500 mAh/g) silicon-carbon nanotube (Si-CNT) anodes, eliminating the 20-40% first cycle irreversible capacity loss. Pressure-activation of SLMP is shown to enhance prelithiation and enable capacity matching between Si-CNT anodes and lithium nickel cobalt aluminum oxide (NCA) cathodes in full batteries with minimal added mass. The prelithiation approach enables high energy density NCA/Si-CNT batteries achieving >1000 cycles at 20% depth-of-discharge.

Acknowledgement vi 3. 1 Purification and Characterization of Single Wall Carbon Nanotubes 41 3.2 SWNT-Polymer Composites 3.3 Characterization of Single Wall Carbon Nanotube-Polymer Composites 3 .4 Evaluation of Single Wall Carbon Nanotube-Polymer Composite Actuators 4.0 Conclusion 5 .0 Appendix 5.1 Preparation of SWNT-Polymer Composite Fibers 6.0 References I wish to thank my advisor, Tom Gennert, for all the support and direction during this thesis project. His guidance and tolerability were much appreciated, causing any future success and recognition I may receive in my scientific pursuits to be based on the solid foundation, which he fortified. I would also like to thank my pseudoadvisor/committee member, Ryne Raffaelle, who has begun the process of teaching me how to critically evaluate scientific data. Lastly, I wish to thank my other committee members, Dr. Andreas Langner and Dr. Michael Kotlarchyk, who were tremendous resources during the research process. Above all, I wish to thank my parents and other family members who consistently support every endeavor I undertake. Also, I appreciate the friends and classmates who challenge me and allow for the development of long-lasting memories. Cheers! vi