Abstract
Although secondary Li-ion batteries are widely used for electrochemical energy storage, low energy (100–300 Wh kg−1) and power density (250–400 W kg−1) are limiting their applications in several areas including long-range electric vehicles. Herein, we demonstrate high energy (400 Wh kg−1) and power density (1 kW kg−1) Li-ion batteries (considering the weight of both electrodes) based on extremely pseudocapacitive interface engineered CoO@3D-NRGO hybrid anodes. These values are 2.8 and 2.3-fold higher respectively compared to graphite‖LiNiMnCoO2 full-cells under similar experimental conditions. Three-dimensional anode architecture presented here composed of ultrafine CoO nanoparticles (∼10 nm) chemically bonded to nitrogen-doped reduced graphene-oxide. This hybrid anode demonstrated excellent pseudocapacitance (∼92%), specific capacity (1429 mAh g−1 @ 25 mA g−1), rate performance (906 mAh g−1 @ 5 A g−1), and cycling stability (990 mAh g−1 after 7500 cycles @ 5 A g−1). Outstanding electrochemical performance of CoO@3D-NRGO‖LiNiMnCoO2 full-cells is credited to the extreme pseudocapacitance of CoO@3D-NRGO anode resulting from Li2O/Co/NRGO nanointerfaces and Co–O–C bonds. The demonstrated strategy of interfacial engineering can also be extended for other environmental friendly/inexpensive transition metal oxide (Fe2O3, MnO2 etc.) anodes for high energy/power density and ultra-long-life Li-ion batteries.
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•Extremely pseudocapacitive CoO@3D-NRGO hybrid Li-ion battery anodes are developed.•Li-ion battery exhibited high energy (400 Wh kg−1) and power density (1 kW kg−1).•These values are 2.8 and 2.3-fold higher compared to graphite anode based system.•Li2O/Co/NRGO nanointerfaces and Co–O–C bonds caused extreme pseudocapacitance.•This strategy provides new opportunities to design advanced Li-ion batteries.