The search for alternatives to the existing energy model is focusing on the use of renewable energies. Due to the fluctuations in energy and the mismatch between the energy supply and its demand, the search for a technology that efficiently stores the energy that is generated in order to use it when necessary is of vital importance. Electrochemical energy storage and conversion seem to be the key solutions to respond to these problems. For instance, among electrochemical devices such as fuel cells and capacitors, rechargeable batteries transform electricity into chemical energy that can be charged and discharged several times to obtain energy when needed. Currently, the electrodes, separators, and membranes used in these devices are derived from fossil fuels. On the way to the sustainable energy transition, eco-friendlier bio-based materials have to be employed. This chapter analyses bio-based alternatives to fossil fuels-based materials and their applications in electrochemical devices.