demonstrated to be effective in enhancing the capacitance of carbon-based materials. For example, N, [4,6] O [7,8] and S [9,10] are the most well studied dopants for carbon-based materials. The functions of these dopants depend on their chemical environments in the carbon host structure and they can improve the capacitive performance of carbon-based materials in different manners. It has been reported that the negatively charged pyridinic N and pyrrolic N can serve as faradaic reaction sites and contribute pseudocapacitance, whereas the positively charged quaternary N can facilitate electron transport in carbon lattice. [7,11] The introduction of O and S doping can increase pseudocapacitance and improve the electrode surface wettability. [12,13] Recently, dual and multi ple heteroatom doping carbon materials have been developed and achieved excellent capacitive performance. [14][15][16] Pore engineering is another effective approach to enhance the capacitive performance of carbonbased materials. [17] First, the introduction of pores, especially micropores, can significantly increase the surface area of carbon materials. Second, the pores function as electrolyte reservoirs that can shorten ion diffusion length. Third, the rational construction of an interconnected network consisting of multiple scale pores can facilitate mass transport of ions. The combination of large surface area and efficient ion diffusion will increase the effective ion accessible surface area and therefore, the specific capacitance. This is particular important for ultrafast supercapacitors electrodes that aim to be operated at high charging/discharging rates. Despite that the pore engineering and elemental doping have been demonstrated separately on different carbon materials, the combination of these approaches has rarely been reported. Herein, we demonstrate a new porous carbon electrode with high level of structural complexity for ultrafast supercapacitors through the integration of tri-doping and pore engineering method in preparation of carbon-based electrodes. Results and DiscussionThe preparation of the N,O,S tri-doped hierarchical porous carbon foam is illustrated in Scheme 1. The precursors including graphene oxide (GO) nanosheets, Poloxamer 407 Carbonaceous materials are attractive supercapacitor electrode materials due to their high electronic conductivity, large specific surface area, and low cost. Here, a unique hierarchical porous N,O,S-enriched carbon foam (KNOSC) with high level of structural complexity for supercapacitors is reported. It is fabricated via a combination of a soft-template method, freeze-drying, and chemical etching. The carbon foam is a macroporous structure containing a network of mesoporous channels filled with micropores. It has an extremely large specific surface area of 2685 m 2 g −1 . The pore engineered carbon structure is also uniformly doped with N, O, and S. The KNOSC electrode achieves an outstanding capacitance of 402.5 F g −1 at 1 A g −1 and superior rate capability of 308.5 F g −1 at 100 A g −1...

Maintaining fast charging capability at low temperatures represents a significant challenge for supercapacitors. The performance of conventional porous carbon electrodes often deteriorates quickly with the decrease of temperature due to sluggish ion and charge transport. Here we fabricate a 3D-printed multiscale porous carbon aerogel (3D-MCA) via a unique combination of chemical methods and the direct ink writing technique. 3D-MCA has an open porous structure with a large surface area of ∼1750 m2 g–1. At −70 °C, the symmetric device achieves outstanding capacitance of 148.6 F g–1 at 5 mV s–1. Significantly, it retains a capacitance of 71.4 F g–1 at a high scan rate of 200 mV s–1, which is 6.5 times higher than the non-3D printed MCA. These values rank among the best results reported for low temperature supercapacitors. These impressive results highlight the essential role of open porous structures for preserving capacitive performance at ultralow temperatures.

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Shearing flow induced spiral self-assembly of multi-shelled nanospheres with unusual chirality in block copolymer micelle system.

Carbon-incorporated NiO/Co3O4 concave surface microcubes (denoted as NCMC) are successfully developed from a precursor of Ni3[Co(CN)6]2 for the first time.

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Non-noble Ni0.5Co0.5 alloy with porous micro/nano “holothurian-like” structure is successfully developed via a hydrogen evolution assisted electrodeposition method. The mechanism for the formation of porous Ni0.5Co0.5 alloy structure is analyzed by X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy. The results show that the hydrogen evolution combined with the anisotropic deposition of Co2+ account for the formation of this “holothurian-like” structure. The catalytic kinetic studies present that the values of proton diffusion coefficient and surface coverage of the redox species for porous Ni0.5Co0.5 are significantly larger than that of Ni film. Also the reaction rate constant for methanol oxidation at porous Ni0.5Co0.5 alloy is improved by more than one order of magnitude. Finally, the cyclic voltammetry and chronoamperometry tests indicate the Ni0.5Co0.5 electrode has a relatively stable redox behavior after 3000 potential cycles and an improved electrocatalytic stability towards methanol oxidation. The enhanced electrocatalytic activity and stability for porous Ni0.5Co0.5 alloy may be ascribed to the high surface area conducive to the mass transfer process and methanol adsorption and the structural effect of porous micro/nano arrays.

High energy and efficient solar charging stations using electrochemical capacitors (ECs) are a promising portable power source for the future. In this work, two kinds of metal‐organic framework (MOF) derivatives, NiO/Co3O4 microcubes and Fe2O3 microleaves, are prepared via thermal treatment and assembled into electrochemical capacitors, which deliver a relatively high specific energy density of 46 Wh kg−1 at 690 W kg−1. In addition, a solar‐charging power system consisting of the electrochemical capacitors and monocrystalline silicon plates is fabricated and a motor fan or 25 LEDs for 5 and 30 min, respectively, is powered. This work not only adds two novel materials to the growing categories of MOF‐derived advanced materials, but also successfully achieves an efficient solar‐ECs system for the first time based on all MOF derivatives, which has a certain reference for developing efficient solar‐charge systems.