Biosourced Polymers and Lignocellulosic Materials for Eco-Friendly Electrochemical Energy Conversion and Storage Devices

In the last 10 years, applied research on electrochemical energy conversion and storage devices market has rapidly grown. In order to lower the cost and reduce the environmental impact of these systems, efforts must be devoted to reduce the amount of inactive components in the cell, to substitute synthetic polymer binders/separators and organic solvents with low-cost and biosourced materials and to develop new eco-friendly processes for the manufacture of cell components (both electrodes and electrolyte). Here we review the use of paper-making technique and selection of biosourced polymers for manufacturing: - Bio-inspired all-paper Li-ion polymer cells, constituted by nanoscale-microfibrillated cellulose (NMFC)-binded paper-electrodes, and NMFC-reinforced polymer electrolytes. The use of NMFC as filler/binder leads to produce high performing, safe and extremely flexible electrolytes for LiBs. No organic solvents or synthetic polymer binders are used during the entire electrode/electrolyte/cell preparation process. - Cellulosic membranes as separators/electrolytes for post-lithium technologies, such as Na-ion and Li-S , thus demonstrating the possibility of obtaining “truly green” energy storage devices in the near future. - Paper-based flexible electrodes and electrolytes for third generation solar cells, useful to lower oil-derived components and typical temperatures used to electrodes processing. - Aqueous solar cells, where biosourced polymeric matrices are used for the preparation of hydrogel electrolytes. This materials platform is promising not only for the sustainable manufacture of energy devices components, but also for their processability at the end of life.