The need for a change in the current energy model towards a future in which sustainability is advocated as an indispensable pillar of progress has led to a change in the energy paradigm. The hitherto used power sources based on the harmful burning of fossil fuels must be eradicated as quickly as possible. In this context, lithium-ion batteries emerge as a viable and environmentally friendly solution. Lithium-ion batteries, given their high energy density, can be used in the transport sector as substitutes for fossil fuels. However, the electrication of the automotive system does not entail a substantial improvement if the power generation continues to come from conventional systems based on the burning of fossil fuels or nuclear energy. The main alternative is to replace these sources with renewable sources. However, a system based solely on uncontrollable renewable resources would be nothing more than a utopia without a storage system to accompany them, such as lithium-ion batteries. This thesis analyses in detail this technology, and in particular, its application in renewable generation environments. The main lines of work are: Analysis of the current state of lithium-ion battery technology; Study of the main non-invasive characterisation techniques as a tool to quantify and identify the degradation mechanisms on lithium-ion batteries; Electrical modelling of lithium-ion batteries and validation in real systems; Study and identication of key aspects of lithium-ion batteries for the integration of renewable energies into the power grid.