Nowadays, modern smart grids require the implementation of Energy Storage Systems (ESS) in order to optimize the production, the consumption and the distribution of electrical energy. In particular, ESS adds a degree of freedom to the system which allows to cover the mismatch between production and demand while providing other grid support services. Lithium Ion Batteries have proven to be mature to serve in several applications involving different stakeholders. In fact, their characteristics in terms of aging, specific power and response times overcome other energy storage technologies. In the first chapters of the thesis typical energy storage applications as well as lithium ion batteries are clustered and discussed.