Flexible cellulose/LiFePO4 paper-cathodes: toward eco-friendly all-paper Li-ion batteries

Today most of commercial Li-ion batteries (LIBs) are manufactured using toxic solvents and synthetic polymer binders. In order to lower the cost and the environmental impact of LIBs an effort must be made to identify low-cost and environmentally friendly materials and processes. In this work, flexible, self-standing and easily recyclable LiFePO4 cathodes are obtained using cellulose fibers as biosourced binder and a quick, aqueous filtration process, easily upscalable capitalizing the well-established papermaking know-how. The obtained paper-cathodes show very good mechanical properties, with Young's modulus as high as 100 MPa, discharge capacity values up to 110 mAh g(-1) and very good cycling performances, comparable with conventional polymer-bonded LiFePO4 cathodes. Moreover, a complete paper-cell, constituted by a paper-cathode, a paper-separator and a paper-anode is presented, showing good cycling performances in terms of specific capacity, efficiency and stability.