Nano and biosourced electrode/electrolyte components for next-gen energy storage and conversion devices

The life style of modern civilization is strongly dependent on the use of portable devices, which necessarily require safe and very efficient storage and conversion energy systems. Nowadays, lithium-ion batteries (LiBs) represent the most widely used storage technology. In order to lower their cost and environmental impact, efforts are devoted to reduce the amount of inactive components, to substitute synthetic polymer binders / separators and organic solvents with nano- and bio-sourced materials and to develop new eco-friendly production processes. Natural nanoscale-microfibrillated cellulose (NMFC) fibers are readily available; they show stiffness, impressive mechanical robustness, lightweight and their preparation process is easy and does not involve chemical reactions. Here we review the manufacturing of low cost, bio-inspired all-paper Li-ion polymer cells, constituted by 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 LiBs. Green, biosourced materials and procedures are also extended to other “beyond-LiB” technologies (i.e., Na-ion and Li-S), as well as next-generation energy conversion devices such as green, water-based dye-sensitized solar cells (DSSC), thus demonstrating the possibility of obtaining “truly green” energy storage and conversion devices in the near future.