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[Display omitted] • Flower-like MoS 2 sheets were encapsulated into the interlayer of N-doped graphene. • The FL-MoS 2 /N-G enables the high loading of MoS 2 and good structural integrity. • The MoS 2 sheets coupled with N-doped graphene can accelerate the charge transfer. • The encapsulation structure of FL-MoS 2 /N-G has low diffusion resistance of Li+ ions. • The target FL-MoS 2 /N-G anode exhibits superior performance for Li+ ion storage. Layered molybdenum disulfide (MoS 2) is a promising anode material for lithium-ion storage and its coupling with graphene can further improve the specific capacity and cycling stability. In this work, a feasible polyacrylamide (PAM)-assisted approach to prepare the flower-like MoS 2 nanosheets encapsulated by nitrogen-doped graphene (FL-MoS 2 /N-G) is proposed. The PAM is taken as the directing agent for the layered assembly of graphene and further confined growth of FL-MoS 2 in the interlayers of the graphene. The unique encapsulation construction of MoS 2 and N-doped graphene leads to the high loading of active species and stabilized structural integrity after the continuous Li+ ion intercalations. Theoretical simulation results reveal that the MoS 2 nanosheets coupled with N-doped graphene can accelerate the charge transfer process and create extra lithiation sites with decreased diffusion resistance of Li+ ions. As the anode material in lithium-ion batteries (LIBs), the target FL-MoS 2 /N-G composite exhibits a high reversible capacity of about 1202 mAh g−1 at 0.2 A g−1 and it can remain 835 mAh g−1 even at 5 A g−1, highlighting an excellent rate capacity. Additionally, the FL-MoS 2 /N-G anode is also capable of delivering a long-term cycling performance with a capacity retention of about 78% after 800 cycles. Furthermore, benefiting from the fast charge transfer process of the FL-MoS 2 /N-G dominated by surface capacitive behavior, the lithium-ion hybrid capacitor with good electrochemical performance was fabricated to brighten its practical application prospect. The current work presents a new insight into the fabrication of high-loading MoS 2 /N-doped graphene composites with unique nanostructures for high-performance lithium-ion storage. [ABSTRACT FROM AUTHOR]

[Display omitted] • N -doped carbon nanosheets were fabricated via a facile templating-assisted strategy. • The N -doped carbon nanosheets showed superior performance in redox electrolytes. • Graphitic N on the carbon scaffolds can accelerate the redox kinetics of iodides. The incorporation of redox-active anions into aqueous electrolytes endows electrodes with enhanced specific energy density for supercapacitors. However, the congruent relationship between the redox chemistry of electrolytes and electrode surfaces is still not well understood. Herein, two-dimensional nitrogen-doped porous carbon nanosheets (denoted as NC- x with x being the carbonization temperature in Degree Celsius) are systematically synthesized by using general dual-crystals templating assisted strategy with pore structure and surface composition optimized. Employed as both positive and negative electrodes, the as-prepared NC-900 with a large specific surface area and ample graphitic N sites shows a high specific capacitance of 251 F g−1 with a voltage window of 1.6 V and energy density of 22.4 Wh kg−1 associated with 86.5% capacity retention after 30,000 cycles using aqueous iodide redox electrolyte. The experimental and theoretical analyses reveal the contributions of nitrogen configurations on the carbon scaffolds to accelerate the redox chemistry of iodides. The enhanced redox performance of the porous carbon nanosheets is linearly proportional to the graphitic N content, which is consistent with the large electron-donating area and the strong adsorption capacity towards iodine species at the graphitic N sites. This work shows a new design strategy of carbon electrodes for high-performance supercapacitors with the aqueous redox electrolytes. [ABSTRACT FROM AUTHOR]