Biomass wastes or biomass derived hard carbon materials with the advantages of green, as well as economic and high reversible capacity have became the promising anode materials for sodium ion batteries (SIBs). Despite this, the poor rate capability hinders their further development. Here, we synthesized lath-shaped hard carbon materials derived from peanut shells by a two-step approach, namely a hydrothermal pretreatment for different treatment time first, and then a carbonized process at 800 °C. Morphology and structural characterizations (SEM, XRD and Raman) prove the hydrothermal pretreatment has a great influence on morphology transformation, the layer spacing, as well as the defect concentration which can enhance the adsorption sites of Na + and shorten the transport route of sodium ions . The PSDHCs-4 (hydrothermal treatment for 4 h) electrode can deliver the highest reversible capacity of 256 ± 5 mAh g −1 , and show the best capacity retention of 97 ± 2% at the current rate of 0.1 C after 100 cycles. More importantly, PSDHCs-4 electrode shows the excellent rate performances with a reversible capacity of 261, 244, 206, 163, 125, and 100 mAh g −1 at the current rates of 0.1, 0.2, 0.5, 1.0, 2.0 and 5.0 C, respectively. These remarkable electrochemical properties indicate that PSDHCs-4 material should be a promising anode material for SIBs.
Hollow carbon nanosheets with predominant mesopores have been demonstrated as a promising electrode material for supercapacitor , but their low specific surface area with relatively low micropore proportion limits their specific capacitance and energy density . Herein, we develop a novel extrusion plant microtube strategy to synthesize micron-sized nitrogen-doped hollow porous carbon nanosheets (MNHPCS) from dandelion fluff having the specific natural thin-wall and hollow tubular bundled structure through high-pressure extrusion, carbonization and KOH activation. The optimized MNHPCS displays strutted bilayer nanosheet structure, large SSA of 1593 m 2 g −1 , high micoporosity of 71.2 % and high heteroatom content (5.2 at.% for N, 7.0 at.% for O). Importantly, MNHPCS prepared by the new technique overcomes the drawbacks of hollow carbon nanosheets and presents an excellent capacitance of 378 F g −1 at 0.5 A g −1 and rate capability of 57 % at 80 A g −1 in 6 M KOH. Furthermore, the energy density of MNHPCS//MNHPCS based supercapacitor in EMIMBF 4 can reach up to 84 Wh kg −1 . Most importantly, MNHPCS can be easily achieved from various plant wastes having hollow tubular structure, which would provide a clearly method on selecting plant precursors for producing hollow porous carbon nanosheets applied on supercapacitors.
危险品化学品经营许可证（带存储）