The report deals with energy conservation, mainly in the field of portable energy, which is asubject that today raises questions around the world. This report describes the design and theimplementation of a Battery Management System on the platform NI ELVIS II+ managed bythe software Labview. The first aim has been on finding information about the design of theBattery Management System that corresponds to the choice of the battery itself. The systemwas designed completely independent with different charging methods, simulations ofdischarge, and its own cell balancing, as a 3 cells battery pack was used. The battery chosenwas the lithium-ion technology that has the most promising battery chemistry and is the fastestgrowing. Several experimentations and simulations have been done, with and without cellbalancing that permited to highlight that the cell balancing is mandatory in a Batterymanagement System. Furthermore, a simulation of use of the battery in an Electrical Vehiclewas made, which can lead to conclude that the Lithium-Ion battery must be manageddifferently to be used in the application of an Electrical Vehicle.

We will introduce our approach to prepare and investigate thin film materials for application in all solid state batteries by using integrated UHV preparation facilities.

Nanofibrous separators use in lithium-ion batteries brings many advantages. In contrast to contemporary used commercial separators, nanofibrous ones exhibit higher temperature resistance,ionic conductivity and higher electrolyte uptake. Better ionic conductivity is ensured by porous structure and large specific surface. Fibers creates channels for the ionic species motion. Amorphous texture of nanofibers allows quick lithium ionic species motion within the polymeric matrix of separator. Furthermore, these separators exhibit higher volume of uptaken electrolyte. Further advantage of electrospinned nanofibrous separators are both high porosity and chemical stability.

This thesis deals with the development and current issues of Li-ion and Li-S accumulators, especially the separators. In the theoretical part is described history of Li-ion batteries, their properties and materials for the positive electrode. Li-S batteries and their problems are also described in this diploma thesis. In the practical part, electrochemical methods were described, and several separator samples with various modifications were created. These samples were then photographed using an SEM electron microscope and evaluated using electrochemical methods.