Preparation and characterization of flexible lithium iron phosphate/graphene/cellulose electrode for lithium ion batteries.

In this work, a free-standing flexible composite electrode was prepared by vacuum filtration method with LiFePO4, graphene and nanofibrillated cellulose (NFC). Compared with the pure LiFePO4 electrode, the resulting flexible composite (LiFePO4/graphene/NFC) electrode showed excellent mechanical flexibility, and possessed an enhanced initial discharge capacity of 151 mA h/g (0.1 C) and a good capacity retention rate with only 5% loss after 60 cycles due to suitable electrolyte wettability at the interface. Furthermore, the NFC and graphene formed a three-dimensional conductive framework, which provided high-speed electron conduction in the composite and reduced electrode polarization during charging-discharging processes. Moreover, the composite electrode could endure bending tests up to 1000 times, highlighting preferable mechanical strength and durability. These results demonstrated that the as-fabricated electrodes could be applied as flexible electrodes with an embedded power supply.