Hybrid mobile ion capacitors (HMIC) have been proposed as a way to incorporate the advantages of both batteries and supercapacitors into one system. Unfortunately, considering the much slower Li+ intercalation/deintercalation process, finding a suitable battery anode material with high rate performance is still a major challenge. Here, we report the fabrication of laser scribed nitrogen-doped graphene (NLSG) with 3D structure as binder-free, and conductive additive-free anode. This NLSG anode has high nitrogen and oxygen doping (8.6 at% and 6.3 at%) leading to the formation of conductive electrodes with expanded lattice spacing, providing more convenient pathways and reaction sites for Li+ ions. Hybrid Li-ion capacitors (HLIC) were assembled by combining the NLSG anodes with hierarchical porous carbon (PC) cathodes obtained by pyrolysis of Ethylenediaminetetraacetic (EDTA) tetrasodium salt. The NLSG//PC hybrid Li-ion capacitors show an energy density (including the total weight of two electrodes) of 186 Wh kg−1 at 200 W kg−1. Even when power density increased to the level of conventional supercapacitors (20 kW kg−1), an energy density of 76 Wh kg−1 can still be obtained. Further, the devices exhibit excellent cycle life, retaining 87.5% of the initial value after 5000 cycles. This study demonstrates that laser scribed graphene is a very promising electrode for mobile ion capacitors.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: The research reported in this publication was supported by King Abdullah University of Science and Technology (KAUST) under the KAUST-King Saud University Battery Initiative (KAUST Grant # REP/1/3804-01). The authors thank the Core Laboratory Staff at KAUST for their support. M.A.D. and Z.A. greatly acknowledge Deanship of Scientific Research at King Saud University for funding research grant no RG#1440-115