Electrochemical energy cells (EECs) are devices that work through a redox (reduction-oxidation) reaction. Between them we have energy storage devices, like Lithium-Ion Batteries (LIBs) cells, and energy conversion devices, like Proton Exchange Membrane Fuel Cells (PEMFCs). Both applications play a crucial role towards the green transition needed to mitigate climate change. Given the intermittent production of renewable energy sources and an on-demand consumption requirement, EECs can help to better integrate these energy sources into the energy matrix. On one side, LIBs present a high energy density, extended lifespan, and low self-discharge that has significantly impacted various industries, including electronics and telecommunications, and served as key components in portable devices. LIBs are also contributing to the electrification of the transportation industry by being used in electric vehicles (EVs). On the other side, PEMFCs presents high efficiency, low operating temperature and zero carbon emissions and can act as an alternative application where EVs face limitations, such as heavy-duty trucks.