A simple route towards next-gen green energy storage by fibre-based self-supporting electrodes and a truly solid polymer electrolyte

To meet the challenge of a green energy economy that could offer the chance to escape from our dependence on fossil fuels, the rapid development of materials science and technology is vital. Nowadays, advanced devices that convert and store energy are the focus of intensive research that is being carried out along various avenues and Lithium-ion batteries (LIBs) in combination with fuel cells and supercapacitors hold the promise for a clean solution for an electric future. Currently, there are a number of efforts underway to develop lithium cells by using renewable resources, to simplify the fabrication processes to lower the costs, and to use water as solvent to reduce the environmental impact. An increased attention is also devoted to the recycling of spent LIBs even though the assessment of the real balance between the economic and environmental impact of this process is still matter of debate. In this respect, a novel and original Li-ion cell architecture is here successfully developed for the first time by exploiting the use of carbonized cellulose nanofibrils as both conductive binder and current collector substrate. The cellulose nanofibrils are also used as a reinforcing agent for the preparation of an unconventional composite polymer electrolyte as separator. The truly solid lab-scale Li-ion cell, assembled in a “pouch cell”, demonstrates remarkably stable cycling characteristics upon prolonged cycling at ambient temperature. The outstanding results are obtained along with the implementation of a pilot line procedure, comprising the spray coating and water-based papermaking techniques. Noteworthy, the battery components after use can be fully recovered using paper recycling techniques, which will definitely open up a truly new way of conceiving advanced sustainable batteries