Sodium-ion batteries (SIBs) have gained more and more interest for grid-level energy storage applications compared with current lithium-ion batteries (LIBs). In this paper, well-uniform and dispersed spindle-shaped NiCo 2 O 4 particles were synthesized by solvothermal method, and then graphene-encapsulated NiCo 2 O 4 (NiCo 2 O 4 @G) was formed core-shell nanostructures , which greatly enhanced the electronic and ionic (electro-active) conduction and also effectively buffering to accommodate the strain. Benefit from its structure feature, the prepared NiCo 2 O 4 @G core-shell nanostructures composite shows good cycling with a capacity of up to ∼400 mAh g −1 (100 mA g −1 ) in 100 cycles for NIBs anode. The facile synthesis process and excellent SIBs behaviors in this paper are expected to be extended in developing other anode materials in battery system.
Sun Zhuangzhi,Du Shanqi,Li Fei,Yang Lu,Zhang Dan,Song Wenlong
A nanocomposite soft actuator based on porous high-conductivity electrode membrane, which was composed of biopolymer cellulose mixed with chitosan and highly conductive nanoparticles generated by reduced graphene oxide encapsulated multi-walled carbon nanotube, was developed in this paper. No new substance was discovered in the regenerated electrode layer through the scanning analysis from FT-IR and XRD. Actuators exhibited significant enhancement in peak to peak displacement, which was 3.64 times increased than the traditional value at 5 V 0.1 Hz. With the test of solid-state electric double layer capacitor, actuators showed the highest specific capacitance (10.695 F g −1 ) at the current density of 1 A g −1 , the lowest internal resistance (9.2 Ω g −1 ) in the frequency range of 10 5 –10 −2 Hz, and the lowest energy density (901 Wh kg −1 ) at the current density of 10 A g −1 , which demonstrated the absolute advantages in the conductivity and channels for electrons. These findings suggest that research on porous high-conductivity electrode layer holds great promise in the further study of higher performance actuators.
The preparation of high specific-capacity pseudocapacitive transition-metal-oxide/hydroxide (TMH) materials into transparent micro-structure electrodes is a great challenge and has become the bottleneck restricting the performance of transparent flexible supercapacitors . Beyond that, extending the operating voltage window is an urgent need for improving energy density . Here, Co(OH) 2 nanosheets and amorphous FeOOH nanowires were prepared into transparent films through a simple and scalable bio-inspired method at the air-solution interface. Both nanostructures are enwrapped in graphene shells (Co@Gr-TFandFe@Gr-TF) for use as transparent asymmetric pseudocapacitive electrodes. The unique encapsulation structures (1) provide pseudocapacitive electrode materials, especially an amorphous FeOOH structure cathode, (2) build up rapid three-dimensional electron and ion transport pathways together with the underlying ITO layer, (3) alleviate the exfoliation and dissolution of the active materials into electrolyte, and (4) extend the potential window of the FeOOH cathode from −0.8 ∼ 0 V to −1.2 ∼ 0 V with minimal cycling stability degradation. The asymmetric transparent and flexible supercapacitor based on Co@Gr-TF//Fe@Gr-TF operated at 1.8 V exhibits good transparency (50.5% at 550 nm), high specific capacitance (25.5 mF cm −2 , one order higher than the maximum value reported for FFT-GP), and high energy density (1.04 mWh cm −3 , comparable to that of nontransparent devices) as well as a long cycle life (10 000 cycles) with high-capacity retention (83.5%).
危险品化学品经营许可证（带存储）