carbon-based electric double layer capacitors(EdLCs)hold tremendous potentials due to their high-power performance and excellent cycle ***,the practical use of EdLCs is limited by the low energy density in aqueous ele...
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carbon-based electric double layer capacitors(EdLCs)hold tremendous potentials due to their high-power performance and excellent cycle ***,the practical use of EdLCs is limited by the low energy density in aqueous electrolyte and sluggish diffusion kinetics in organic or/and ionic liquids ***,3d carbon frameworks(3dCFs)constructed by interconnected nanocages(10-20 nm)with an ultrathin wall of ca.2 nm have been fabricated,which possess high specific surface area,hierarchical porosity and good conductive *** deoxidization,the deoxidized3dCF(3dCFdO)exhibits a record low IR drop of 0.064 V at 100 A g^−1 and ultrafast charge/discharge rate up to 10 V s^−*** relateddevice can be charged up to 77.4%of its maximum capacitance in 0.65 s at 100 A g^−1 in 6 M *** has been found that the 3dCF-dO has a great affinity to EMIMBF4,resulting in a high specific capacitance of 174 F g^−1 at 1 A g^−1,and a high energy density of 34 Wh kg^−1 at an ultrahigh power density of 150 kW kg^−1 at 4 V after a fast charge in 1.11 *** work provides a facile fabrication of novel 3d carbon frameworks for supercapacitors with ultrafast charge/discharge rate and high energy-power density.
A one-step sol-gel synthesis of porous carbon micro/nanospheres (PCMNSs) through cationic surfactant with two long hydrophobic chains was reported to realize the tunable synthesis of carbon nanospheres with inter-conn...
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A one-step sol-gel synthesis of porous carbon micro/nanospheres (PCMNSs) through cationic surfactant with two long hydrophobic chains was reported to realize the tunable synthesis of carbon nanospheres with inter-connected structures between the shell and shell. The unique pore structure of PCMNSs endows the material with efficient electrochemical energy storage performance. The abundant macropores and mesopores of PCMNSs can promote the transport of electrolyte by reducing diffusion distances and provide sufficient active sites for effective charge storage and the charge transfer can be greatly increased by the interconnected channel structure among the carbon spherical shells. By adjusting the amount of surfactant and the consumption of ethanol, the controllable synthesis of individual carbon spheres to three-dimensional carbonframeworks were successfully realized. The results showed that the representative sample A-PCMNSs-0.6-35 had excellent supercapacitive performance, excellent electrochemical specific capacitance (242 F g(-1) at 1 A g(-1)), great capacitance retention (170 F g(-1) at 1 A g(-1)) and superior cycle stability (93% at 10 A g(-1) after 5000 cycles).
Finding novel anode materials in place of the current commonly used but performance-limited graphite is the top priority for the remarkable development of lithium-ion batteries (LIBs). Although impressive reports have...
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Finding novel anode materials in place of the current commonly used but performance-limited graphite is the top priority for the remarkable development of lithium-ion batteries (LIBs). Although impressive reports have been published, certain problems, such as complicated synthesis processes, limited production, high cost of raw materials, and lack of truly durable and high-capacity performance, are still hindering the actual applications of LIBs. In this work, we report a mass-produced3d nitrogen-dopedcarbon framework (NCF) that uses low-cost polyacrylonitrile (PAN) as the precursor. A simple sol-gel method is used to prepare the anode materials for ultra-long life LIBs, through which 24.35 g samples can be easily prepared at the laboratory level. This method also ensures that samples with certain morphologies, crystal structures, and nitrogen of specific contents and species can be prepared by the simple control of the pyrolysis temperature. Benefitting from the unique structure, NCFs-800 exhibits excellent rate performance, with its lithium ion storage capacity maintained as high as 41.4% from 675 mAh g(-1) to 279 mAh g(-1) when the current density increases 100-fold from 0.1 A g(-1) to 10 A g(-1). Furthermore, the electrode of NCFs-800 possesses an ultra-long lifespan of over 10,000 cycles with stable capacity retention exceeding 54%, corresponding to a remarkably slow capacity loss of 0.0046% per cycle. After deep cycling at 10 A g(-1), a relatively high capacity of 124 mAh g(-1) can be retained, which is consistent with the theoretical capacity of cathode materials. Therefore, this kind of material is perfect for industrialization, given the low cost of raw materials, easily scaled up methods, and excellent lithium storage performance.
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