The research discussed is divided into two parts. The first part discusses the background work involved in preparation of the Li-ion cell testing stage. This includes the preparation of anodes using the doctor blade and a calendar mill, electrolyte preparation, test cell assembly, the Li-ion test cell design, and experiments performed to troubleshoot the cell. The second part deals with the cell testing experiments. Li-ion batteries are amongst the most promising rechargeable battery technology because of their high capacity and low weight. Current research aims at improving the anode quality to increase the capacity. The experiments discussed evaluate the traditional anode materials like SFG44 graphite and conducting grade graphite against the novel ones– and tin oxide (SnO2) based and carbon encapsulated tin based anodes. The solid electrolyte interphase formed on each anode was analyzed to understand the initial capacity fade leading to conditioning of the cell thus stabilizing its performance.

L’industrie de l’aluminium vit des bouleversements économiques, d’où l’importance de réduire les coûts d’opération. Le présent projet se penche sur les pertes ohmiques du scellement anodique. Les essais ont été complétés entre les conditions ambiantes jusqu’à charge et température maximales permises par le banc d’essais. Les travaux furent complétés sur un banc d’essais novateur - permettant une stabilisation rapide de la température et une faible oxydation de la portion carbonée de l’échantillon - et des échantillons (acier-fonte-carbone) fabriqués pour reproduire la réalité. Ensuite, une régression non linéaire a été utilisée pour modéliser le comportement mesuré en laboratoire. L’analyse statistique démontre que le modèle représente adéquatement le comportement des interfaces à mesure que la charge appliquée et la température s’intensifient. La comparaison avec la littérature démontre une similitude, toutefois les résultats diffèrent de façon significative. Ceci s’explique par l’utilisation de matériaux différents et par le changement de méthode expérimentale. / The aluminum industry faces economical headwinds, thus needing to reduce its operating costs. The project studies specifically energy losses at anode sealing location. Experiments were conducted from room conditions up to the maximum capacity of the bench test. Laboratory work was completed using tri-material samples (made in such a way to replicate accurately reality) and an innovative bench test using magnetic induction as a source of heat that enables minimal heat-up time and sample oxidation during experiments. Non-linear regression was then used to retrieve a model from laboratory results. Analysis showed that a power model represents accurately the interfaces behavior from room to operation conditions. Comparison with literature showed that the order of magnitude is the same but results are not similar. This observation can be explained by the use of slightly different materials and also due to the use of a different experimental procedure.

Li-ion thin film battery technology has attracted much attention in recent years due to its highest need in portable electronic devices. Development of new materials for lithium ion battery (LIB) is very crucial for enhancement of the performance. LIB can supply higher energy density because Lithium is the most electropositive (-3.04V vs. standard hydrogen electrode) and lightest metal (M=6.94 g/mole). LIBs show many advantages over other kind of batteries such as, high energy density, high power density, long cycle life, no memory effect etc. The major work presented in this thesis is on the development of nanostructured materials for anode of Li-ion battery. It involves the synthesis and analysis of grapheme nanosheet (GNS) and its performance as anode material in Li ion battery. We studied the synthesis of GNS over different substrates and performed the anode studies. The morphology of GNS has great impact on Li storage capacity. Tin and Tin oxide nanostructures have been embedded in the GNS matrix and their electrochemical performance has been studied. Chapter 1 gives the brief introduction about the Li ion batteries (LIBs), working and background. Also the relative advantages and characterization of different electrode materials used in LIBs are discussed. Chapter 2 discusses various experimental techniques that are used to synthesize the electrode materials and characterize them. Chapter3 presents the detailed synthesis of graphene nanosheet (GNS) through electron cyclotron resonance (ECR) microwave plasma enhanced chemical vapor deposition (ECR PECVD) method. Various substrates such as metallic (copper, Ni and Pt coated copper) and insulating (Si, amorphous SiC and Quartz) were used for deposition of GNS. Morphology, structure and chemical bonding were analyzed using SEM, TEM, Raman, XRD and XPS techniques. GNS is a unique allotrope of carbon, which forms highly porous and vertically aligned graphene sheets, which consist of many layers of graphene. The morphology of GNS varies with substrate. Chapter 4 deals with the electrochemical studies of GNS films. The anode studies of GNS over various substrates for Li thin film batteries provides better discharge capacity. Conventional Li-ion batteries that rely on a graphite anode have a limitation in the capacity (372 mAh/g). We could show that the morphology of GNS has great effect in the electrochemical performance and exceeds the capacity limitation of graphite. Among the electrodes PtGNS shown as high discharge capacity of ~730 mAh/g compare to CuGNS (590 mAh/g) and NiGNS (508 mAh/g) for the first cycle at a current density of 23 µA/cm2. Electrochemical impedance spectroscopy provides the various cell parameters of the electrodes. Chapter 5 gives the anodic studies of Tin (Sn) nanoparticles decorated over GNS matrix. Sn nanoparticles of 20 to 100nm in size uniformly distributed over the GNS matrix provides a discharge capacity of ~1500 mAh/g mAh/g for as deposited and ~950 mAh/g for annealed Sn@GNS composites, respectively. The cyclic voltammogram (CV) also shows the lithiation and delithiation process on GNS and Sn particles. Chapter 6 discusses the synthesis of Tinoxide@GNS composite and the details of characterization of the electrode. SnO and SnO2 phases of Tin oxide nanostructures differing in morphologies were embedded in the GNS matrix. The anode studies of the electrode shows a discharge capacity of ~1400 mAh/g for SnO phase (platelet morphology) and ~950 mAh/g for SnO2 phase (nanoparticle morphology). The SnO phase also exhibits a good coulumbic efficiency of ~95%. Chapter 7 describes the use of SnO2 nanowire attached to the side walls of the GNS matrix. A discharge capacity of ~1340 mAh/g was obtained. The one dimensional wire attached to the side walls of GNS film and increases the surface area of active material for Li diffusion. Discharge capacity obtained was about 1335 mAhg-1 and the columbic efficiency of ~86% after the 50th cycle. The research work carried out as part of this thesis, and the results have summarized in chapter 8.