Superb Electrochemical Performance Research Articles

Porous Aromatic Frameworks Enabling Polyiodide Confinement toward High Capacity and Long Lifespan Zinc-Iodine Batteries.

Aqueous zinc-iodine batteries (AZIBs) are attracting increasing attention because of their high safety and abundance of resources. However, the performance of AZIBs is compromised by inadequate confinement of soluble polyiodides, the undesired shuttle effect, and slow reaction kinetics. In this study, a porous aromatic framework (PAF) with abundant benzene motifs and a well-organized pore structure is adopted as the iodine host, which exhibits high iodine adsorption capacity and robust polyiodide confinement. Both experimental characterizations and theoretical simulations indicate that the interactions between iodine species and the PAF-1 facilitate the redox reaction by coupling the electronic structures of the active species in the framework. A comparison of PAF-1, PAF-5, and PAF-11 also emphasizes the structural advantages of the high surface area and interconnected three-dimensional channels of PAF-1. Consequently, the I2@PAF-1 cathode can deliver a high capacity of 328 mAh g-1 at 0.5 C, outstanding rate performance, and a stable cycling life of 20000 cycles (86 % retention at 10 C). The robust polyiodide confinement and superb electrochemical performance of Zn-I2@PAF-1 provide insights into the practical application of PAFs as excellent electrode materials for AZIBs.

Pre-oxidized and composite strategy greatly boosts performance of polyacrylonitrile/LLZO nanofibers for lithium-metal batteries

The active cyano-group in polyacrylonitrile has severe passivation of lithium anode under larger current density, which restricts the wide application of polyacrylonitrile(PAN) in lithium metal batteries. Herein, in order to address the excessive passivation of lithium metal by PAN, inspired by the pre-oxidation of carbon fibers, PAN was pre-oxidized at 230 °C, which transformed part of the cyano group into a more chemically stable cyclized structure. The electrochemical and mechanical properties of the composite solid electrolyte were effectively improved by introducing the fast ionic conductor Li6.25La3Zr2Al0.25O12 into PAN by electrospinning. The oxidized PAN-based composite solid electrolyte presents high ionic conductivity (3.05 × 10−3 S·cm−1) and high lithium transference number of 0.79 at 25 °C, further contributing to a high electrochemical window (5.3 V). The solid-state batteries assembled by Li||10 wt%-LLZAO@230-oxy-PAN||NCM523 behave superb electrochemical performance, delivering a high initial discharge capacity of 157 mAh g−1 at 0.2 C. After 100 cycles, the capacity retention was 93.3 %, indicating the electrolyte displays great electrochemical stability. This work provides new insights into the structural design of polymer-based high-voltage batteries.

Asymmetric Trihalogenated Aromatic Lithium Salt Induced Lithium Halide Rich Interface for Stable Cycling of All-Solid-State Lithium Batteries.

Solid polymer electrolytes (SPEs) are the key components for all-solid-state lithium metal batteries with high energy density and intrinsic safety. However, the low lithium ion transference number (t+) of a conventional SPE and its unstable electrolyte/electrode interface cannot guarantee long-term stable operation. Herein, asymmetric trihalogenated aromatic lithium salts, i.e., lithium (3,4,5-trifluorobenzenesulfonyl)(trifluoromethanesulfonyl)imide (LiFFF) and lithium (4-bromo-3,5-difluorobenzenesulfonyl)(trifluoromethanesulfonyl)imide (LiFBF), are synthesized for polymer electrolytes. They exhibit higher t+ values and better compatibility with Li metal than conventional lithium bis(trifluoromethanesulfonyl) imide (LiTFSI). Due to the trihalogenated aromatic anions, LiFFF- and LiFBF-based electrolytes are prone to generate an LiF- and LiBr-rich solid electrolyte interphase (SEI), therefore increasing the stability of the solid electrolyte/anode interface. Particularly, LiFBF could induce a LiF/LiBr hybrid SEI, where LiF shows a high Young's modulus and high surface energy for homogenizing Li ion flux and LiBr exhibits an extremely low Li ion diffusion barrier in the SEI layer. As a result, the Li/Li symmetric cells could remain stable for more than 1200 h without a short circuit and the LiFePO4/Li batteries showed superb electrochemical performance over 1200 cycles at 1 C. This work provides valuable insights from the perspective of lithium salt molecular structures for high-performance all-solid-state lithium metal batteries.

Engineering preparation of the nanocomposite containing CoWO4 nanodots and its high electrochemical activities

Designing hybrid composites electrodes with hierarchical nano-structural features and superb electrochemical performances sites is vital factor for engineering advanced supercapacitors. Herein, a novel nanocomposite from CoWO4 nanodots anchored on olive derived activated carbon doped with N and S (OACNS) is successfully prepared via an in-situ hydrothermal process. The well dispersion of the CoWO4 nanodots (pseudo-capacitor type) with ca. 7 nm in diameter on the OACNS nanosheets prevents their agglomerations to build hierarchical porous structure with high surface area (162.8 cm2·g−1) and various pores sizes distribution. Noteworthy, through the synergistic effect, the composite shows superb capacitance value of 152 mAh·g−1 (0.5 A·g−1) and splendid life cycle of 93.5 % (via 12,000 cycles). Interestingly, an asymmetric CoWO4@OACNS//OACNS hybrid supercapacitor provides excellent specific energy (53.6 Wh·kg−1) at maximum specific power of 650 W·kg−1. Such fascinating electrochemical performance indicates that the proposed CoWO4@OACNS hybrid composite can be exploited as cathode for next generation of energy storage devices.

Rational design of hierarchical nanoporous yolk-shell Co9S8@ZnGa2S4 heterostructured cages as novel electrode for energy storage systems

State-of-the-art nanomaterials with multi-components and complex topologies demonstrate tremendous potential in fabricating electrode materials with high performance which are used in green energy storage systems. Thereby, we report for the first time on the synthesis of hierarchical yolk-shell Co9S8@ZnGa2S4 heterostructured cages (HYC-CS@ZGS) by a facile metal−organic framework (MOF)-assisted approach as a new electrode material for enhanced hybrid supercapacitors (HSCs). Starting with a solid zeolitic imidazolate framework (ZIFs; termed ZIF-67) as the template, ZIF-67@ZIF-8 core-shell polyhedrons (CSPs) are obtained through an epitaxial growth process. Afterward, ZIF-67@ZIF-8 CSPs are controllably transformed into HYC-CS@ZGS via a reflux procedure. Taking advantage of the synergistic effects between the constituent metals and the hierarchical hollow geometry, the organized HYC-CS@ZGS cages exhibit superb electrochemical performance for supercapacitors (SCs). As a result, the electrode demonstrates an ultrahigh specific capacity of 1018C g−1 at 5 mA cm−2 with a 61 % capacity retention at an ultrahigh current density of 187.5 mA cm−2. Consequently, the assembled HYC-CS@ZGS//AC device renders the highest specific energy of 61.9 W h kg−1 at a specific power density of 64 kW kg−1 with excellent cycle life (just 8.7 % loss after 10,000 cycles).

Controlled Synthesis of Flower-like Hierarchical NiCo-Layered Double Hydroxide Integrated with Metal-Organic Framework-Derived Co@C for Supercapacitors.

Layered double hydroxides (LDHs) have come to the foreground recently, considering their unique layered structure and short ion channels when they act as electrode materials for supercapacitors (SCs). However, due to their poor rate and cycle performance, they are not highly sought after in the market. Therefore, a flower-like hierarchical NiCo-LDH@C nanostructure with flake NiCo-LDH anchored on the carbon skeleton has emerged here, which is constructed by calcination and hydrothermal reaction and applying flake ZIF-67 as a precursor. In this structure, NiCo-LDH grows outward with abundant and homogeneously distributed Co nanoparticles on Co@C as nucleation sites, forming a hierarchical structure that is combined tightly with the carbon skeleton. The flower-like hierarchical nanostructures formed by the composite of metal-organic frameworks (MOFs) and LDHs have successfully enhanced the cycle and rate performance of LDH materials on the strength of strong structural stability, large specific surface area, and unique cooperative effect. The NiCo-LDH@C electrode displays superb electrochemical performance, with a specific capacitance of 2210.6 F g-1 at 1 A g-1 and 88.8% capacitance retention at 10 A g-1. Furthermore, the asymmetric supercapacitor (ASC) constructed with NiCo-LDH@C//RGO reveals a remarkable energy density of 45.02 W h kg-1 with a power density of 799.96 W kg-1. This project aims to propose a novel avenue to exploit NiCo-LDH electrode materials and provide theory and methodological guidance for deriving complex structures from MOF derivatives.

Extraordinarily stable and wide‐temperature range sodium/potassium‐ion batteries based on 1D SnSe2‐SePAN composite nanofibers

AbstractDeveloping electrodes with long lifespan and wide‐temperature adaptability is crucial important to achieve high‐performance sodium/potassium‐ion batteries (SIBs/PIBs). Herein, the SnSe2‐SePAN composite was fabricated for extraordinarily stable and wide‐temperature range SIBs/PIBs through a coupling strategy between controllable electrospinning and selenylation, in which SnSe2 nanoparticles were uniformly encapsulated in the SePAN matrix. The unique structure of SnSe2‐SePAN not only relieves drastic volume variation but also guarantees the structural integrity of the composite, endowing SnSe2‐SePAN with excellent sodium/potassium storage properties. Consequently, SnSe2‐SePAN displays a high sodium storage capacity and excellent feasibility in a wide working temperature range (−15 to 60°C: 300 mAh g−1/700 cycles/−15°C; 352 mAh g−1/100 cycles/60°C at 0.5 A g−1). At room temperature, it delivers a record‐ultralong cycling life of 192 mAh g−1 that exceeds 66 000 cycles even at 15 A g−1. It exhibits extremely superb electrochemical performance in PIBs (157 mAh g−1 exceeding 15 000 cycles at 5 A g−1). The ex situ XRD and TEM results attest the conversion‐alloy mechanism of SnSe2‐SePAN. Also, computational calculations verify that SePAN takes an important role in intensifying the electrochemical performance of SnSe2‐SePAN electrode. Therefore, this study breaks new ground on solving the polyselenide dissolution issue and improving the wide temperature workable performance of sodium/potassium storage. image

High-Performance Alkali Metal Ion Storage in Bi2Se3 Enabled by Suppression of Polyselenide Shuttling Through Intrinsic Sb-Substitution Engineering.

Bismuth selenide holds great promise as a kind of conversion-alloying-type anode material for alkali metal ion storage because of its layered structure with large interlayer spacing and high theoretical specific capacity. Nonetheless, its commercial development has been significantly hammered by the poor kinetics, severe pulverization, and polyselenide shuttle during the charge/discharge process. Herein, Sb-substitution and carbon encapsulation strategies are simultaneously employed to synthesize SbxBi2-xSe3 nanoparticles decorated on Ti3C2Tx MXene with encapsulation of N-doped carbon (SbxBi2-xSe3/MX⊂NC) as anodes for alkali metal ion storage. The superb electrochemical performances could be assigned to the cationic displacement of Sb3+ that effectively inhibits the shuttling effect of soluble polyselenides and the confinement engineering that alleviates the volume change during the sodiation/desodiation process. When used as anodes for sodium- and lithium-ion batteries, the Sb0.4Bi1.6Se3/MX⊂NC composite exhibits superior electrochemical performances. This work offers valuable guidance to suppress the shuttling of polyselenides/polysulfides in high-performance alkali metal ion batteries with conversion/alloying-type transition metal sulfide/selenide anode materials.

Physiological fluid based flexible NbN||TiN supercapacitor for biocompatible energy storage applications

For medical electronic devices, batteries and capacitors are crucial power sources. However, several challenges are associated with these power sources, such as their inflexibility, poor performance, and non-biocompatibility. In this work, a flexible and biocompatible supercapacitor device was fabricated with niobium nitride (NbN) and titanium nitride (TiN) electrodes. Magnetron sputtering was used to deposit NbN and TiN directly on stainless steel-304 (SS). The fabricated asymmetric supercapacitor device (NbN@SS||TiN@SS) demonstrated efficient electrochemical stability, with excellent electrode material adhesion on the substrate, high capacitive performance, and excellent cyclic stability (87.11 % capacitive retention after 10,000 cycles at 0.2 mAcm−2 current density) in physiological fluid (phosphate buffer saline). The device delivered a voltage window of 1.2 V, with superb electrochemical performance (areal energy and power density of 1.86 µWhcm−2 and 239.14 mWcm−2 respectively). Cell viability studies were performed to establish the in-vitro biocompatibility of the electrodes. There was significant cell growth (93 % for TiN@SS and 94 % for NbN@SS) and excellent protein adsorption after 72 h incubation of L929 fibroblasts. These astounding outcomes and the ideal bending electrochemical performance make it a potential candidate for powering medical and implantable electronic devices by directly utilizing physiological fluid.

High-performance electrode of ZIF-67 metal-organic framework (MOF) loaded laser-induced graphene (LIG) composite for all-solid-state supercapacitor

This work demonstrates a facile and efficient methodology to synthesize a composite material of zeolitic imidazolate frameworks (ZIFs) and laser-induced graphene (LIG). This ZIF-67 loaded LIG composite (ZIF-67/LIG) has been adequately characterized for its morphology and structure, and its electrochemical performance has been specifically examined. As supercapacitors (SCs) electrode material, the ZIF-67/LIG composite exhibits superb electrochemical performance, owing to the inherent high porosity, abundant active sites, large specific surface area of ZIF-67, and the excellent conductive three-dimensional hierarchical porous network structure provided by LIG. In three-electrode system, ZIF-67/LIG composite electrode displays outstanding areal specific capacitance (C A) of 135.6 mF cm−2 at a current density of 1 mA cm−2 with 1 M Na2SO4 aqueous electrolyte, which is far greater than that of pristine LIG (7.7 mF cm−2). Furthermore, the ZIF-67/LIG composite has been fabricated into an all-solid-state planar micro-supercapacitor (MSC). This ZIF-67/LIG MSC exhibits an impressive C A of 38.1 mF cm−2 at a current density of 0.20 mA cm−2, a good cycling stability of 80.3% capacitance retention after 3000 cycles, and a high energy density of 5.29 μWh cm−2 at a power density of 0.1 mW cm−2. All electrochemical results clearly manifest that as-prepared ZIF-67/LIG composite can be a candidate in energy storage field with exciting possibilities.

Directly-regenerated LiCoO2 with a superb cycling stability at 4.6 V

The exponential growth of “3C” (computer, communication, and consumer electronics) market generates an ever-increasing demand on recycling materials from the end-of-life LiCoO2 (LCO) batteries with ecological and efficient methods. Herein, we present a direct and scalable approach to recycle the degraded LCO by healing and stabilizing their damaged structure via solid reactions. The as-proposed approach constructs a protective layer onto the regenerated LCO particles to suppress the O3 to H1–3 phase transition at 4.55 V. Benefiting from the unique design, superb electrochemical performance was achieved for the regenerated LCO, exhibiting a high specific capacity retention of 85.9% after 100 cycles with a charging cut-off voltage of 4.6 V and a superb rate capability, which are even superior to those of the pristine commercial LCO. In addition, compared with the LCO production with raw chemicals, the as-proposed healing-stabilizing strategy reduces the total energy consumption by 68.5%, bringing noteworthy economic and environmental benefits. This work provides not only new understandings to stabilize LCO at high voltage, but also a practical solution to the closed-loop development of LCO batteries.

A Nonflammable Organic Electrolyte with a Weak Association State for Zinc Batteries Operated at −78.5 °C

AbstractTraditional rechargeable Zn batteries fail to work in cold regions due to the high freezing point (Tf) and severe corrosivity of the aqueous electrolytes with excessive association (solvent‐solvent and solute‐solvent interactions). In this study, a nonflammable weak‐associated electrolyte (WASE) consisting of ZnCl2 salt and methanol/dichloromethane mixture as a solvent is developed to achieve high reversible Zn plating/stripping at low temperatures. The low self‐association interaction of the mixed solvent not only endures WASE with a low Tf of −119.2 °C but also facilitates the desolvation of interfacial Zn2+ and induces smooth Zn plating at low temperatures. Moreover, the water‐free WASE inhibits the hydrolysis of ZnCl2 and thus restrains the corrosion of Zn electrodes. Thanks to the above merits, the Zn||Zn, Zn||Cu, and Zn||polyaniline cells with WASE exhibit superb electrochemical performance at temperatures as low as −78.5 °C.

All-Solid-State Thin-Film Lithium-Sulfur Batteries

HighlightsThe all-solid-state thin-film Li-S battery has been successfully developed by stacking VGs-Li2S cathode, lithium-phosphorous-oxynitride (LiPON) solid electrolyte, and Li anode.The obtained VGs-Li2S thin-film cathode exhibits excellent long-term cycling stability (more than 3,000 cycles), and an exceptional high temperature tolerance (up to 60 °C).The superb electrochemical performance can be attributed to the favorable compatibility and outstanding interfacial stability between VGs-Li2S thin film and LiPON.

Boosting the Electrocatalytic Formic Acid Oxidation Activity via P-PdAuAg Quaternary Alloying.

Direct formic acid fuel cells (DFAFCs) are considered promising sustainable power sources due to their high energy density, nonflammability, and low fuel crossover. However, serious CO poisoning and activity attenuation of the anodic formic acid oxidation reaction (FAOR) greatly restrict the output and durability of DFAFCs. Inspired by the specific relationship between the composition, type, and property of alloys, in this work, we synthesize a series of hybrid substitutional/interstitial quaternary alloys P-PdAuAg by means of a novel polyphosphide route to address these issues. Due to the simultaneous interstitial P-doping and metal (Au, Ag, Pd) co-reduction, the P-PdAuAg quaternary alloy obtained is only 3 nm in diameter with abundant defects. It not only achieves a new high mass activity of 8.08 A mgPd-1 (6.78 A mgcatalyst-1) but also maintains high stability in the high potential range and harsh reaction conditions. Both the activity and anti-poisoning ability are far exceeding those of the currently reported FAOR catalysts. Detailed density functional theory (DFT) calculations reveal that the superb electrochemical performances originate from the shift of the d-band center of Pd as a result of the synergistic electronic/ligand effects between Pd, Au, Ag, and P. The introduction of interstitial P inhibits the occurrence of an indirect reaction pathway on Pd, while Au and Ag suppress the adsorption of CO and optimize the sequential dehydrogenation steps, leading to boosted reaction kinetics and CO tolerance. This work pioneered a facile way for the synthesis of Pd-based substitutional/interstitial hybrid alloys, providing a promising means of further improving the performance of alloying catalysts.

NiFeZnP Nanosheets with Enriched Phosphorus Vacancies for Supercapattery Electrodes

Designing and fabricating outstanding electrode materials via simple preparation routes are viable ways for improving the performance of electrochemical supercapacitors. We report on the synthesis of NiFeZn phosphide interconnected nanosheets with abundant phosphorus vacancies (Pv-NiFeZnP) via a facile reduction route at room temperature. The fabricated Pv-NiFeZnP was fully characterized using energy-dispersive spectroscopy, field emission scanning electron microscopy, electron paramagnetic resonance, and X-ray photoelectron spectroscopy techniques. Owing to the porous interconnected nanosheet structure and the superior stability enabled by the direct binder-free growth on Ni foam, the Pv-NiFeZnP electrode, with optimized phosphorus vacancy formation, exhibits a superb electrochemical performance of 631.8 mC/cm2 (equivalent to 1579.5 mF/cm2), which is significantly higher than those reported in the literature. Also, the Pv-NiFeZnP||activated carbon asymmetric device exhibits a very high Coulombic efficiency (∼100%) and excellent long-term stability (98.8% capacity retention after 7500 cycles). The fabricated device can deliver 122.1 μWh/cm2 energy density at a power density of 750 μW/cm2. The fabricated NiFeZnP electrode is therefore a promising candidate for supercapacitor applications.

Highly flexible and compressible zinc-ion batteries with superb electrochemical performance enabled by a dual structural regulation strategy

Aqueous zinc-ion batteries (ZIBs) have attracted considerable research attention recently owing to their superior features. However, various critical issues, such as insufficient energy density, poor rate capability, short cycle life, and overlooked mechanical stability, seriously impede their practical application. Although numerous efforts have been devoted to ZIBs improvement, their performance boost is usually unsatisfactory and one-sided. Herein, a simple and versatile strategy is proposed to simultaneously address these issues through synergistic dual structural regulation of the electrodes. The structural orientation regulation of electrode not only facilitate electrolyte diffusion and ion transfer, but also make the electric field distribution and Zn2+ ion flux more uniform. Consequently, the resulting ZIBs exhibit great rate capability and stunning cycling stability (around 0.0003% of attenuation per cycle). On this basis, the further structural size regulation of electrode endues the ZIBs with both ultrahigh MnO2 loading (202.53 mg cm−3) and remarkable volumetric energy density (43.11 mWh cm−3), outperforming most of the state-of-the-art batteries of this kind. Additionally, the tenacious electrodes endow the fabricated ZIBs with coveted flexibility, compressibility, and extremely high safety, well suited to the needs of wearable electronics. This work provides a much more facile and promising way for the design of advanced ZIBs with excellent electrochemical performance and unparalleled mechanical toughness.

Compression-tolerant supercapacitor based on NiCo2O4/Ti3C2Tx MXene/reduced graphene oxide composite aerogel with insights from density functional theory simulations

Compression-tolerant electrodes are critical for developing next-generation wearable energy storage devices. However, most of previous studies on compressible electrodes focus on carbon-based materials, whereas metal-based materials such as spinel metal oxide with faradaic nature have been rarely studied due to their lack of compressibility. Herein, NiCo2O4 (NCO) microtubes assembled by ultrathin and mesoporous nanosheets, are deposited on/into Ti3C2Tx MXene/reduced graphene oxide aerogel (MGA), an intrinsically compressible host template with high conductivity and specific surface areas. The optimized NCO/MGA-300 sample shows a reversible compressive strain of 60% and a superior durability. Density functional theory (DFT) calculations reveal that the NCO/MGA-300 heterojunction has high electronic conductivity, fast electron transfer ability, and low adsorption energy for OH– ions. As a result, the NCO/MGA-300 electrode exhibits superb electrochemical performance in terms of its high gravimetric capacitance (1633F g−1 at 1 A g−1), rate performance (1492F g−1 at 10 A g−1), and remarkable cycling stability of 86.6% after 10,000 charge-discharging cycles. Moreover, an assembled asymmetric supercapacitor based on compressible NCO/MGA-300 shows stable electrochemical performances under different compressive strains (20%. 40% and 60%), or after 100 compression-release cycles. This research finding demonstrates the possibility of metal-based electrode for wearable devices with high energy storage capability and good compressibility.

Deficient TiO2−x coated porous SiO anodes for high-rate lithium-ion batteries

The porous structure of SiO particles provide abundant diffusion channels for lithium ions and the outer TiO2−x favor the generation of stable SEI layer, ensuring the superb electrochemical performance of porous SiO/TiO2−x composites.

Uniform carbon coating mediated multiphase interface in submicron sized rodlike cobalt ditelluride anodes for high-capacity and fast lithium storage

Cobalt ditelluride (CoTe2) is an attractive anode material for lithium-ion batteries due to its unique metallic characteristic, multiple crystal structure, and high density. However, the poor stability and slow-charging capability limit the practical application. While the effective strategy of nano-engineering brings lower volumetric capacity and more irreversible side reactions. In this work, a strategy of constructing abundant inner heterogeneous (carbon/CoTe2) and homogeneous (orthorhombic/hexagonal CoTe2) interfaces in submicron-scale electrode, instead of exposing the high external surface in nanoscale electrodes, is proposed. Structural, morphology, and composition characterization, combined with the electrochemical analysis reveal the multiphase interface in CoTe2 mediated by uniform carbon coating can remarkably strengthen the structure stability and promote the electrons/ions transport. The resultant optimal electrode exhibits a superb electrochemical performance with a rising discharge capacity up to 807 mA h g−1 (600.2 mA h cm−3) at 0.2 C (1 C = 600 mA g−1) after 200 cycles, as well as a stabilized capacity of 438 mA h g−1 (325.7 mA h cm−3) at 1 C after 400 cycles. This success can expand to other anode materials with multiple crystal phases to promote the energy storage.

Design of N-doped carbon materials using self-template strategy for high-performance supercapacitor electrodes and CO2 capture

Hierarchical N-doped porous carbons were synthesized using a self-templated and solvent-free assembly approach via directly heating green polyaspartic acid potassium. The samples prepared under different calcining temperatures were characterized, which exhibited the structural features of high pore volume (0.88–1.75 cm 3 /g) and large specific surface area (1592–3133 m 2 /g). Subsequently, these samples were applied for selective CO 2 capture and supercapacitor electrodes. The N-PCM-900 prepared at 900 °C afforded superb electrochemical performance, including extremely large specific capacitance (346 F/g at 1 A/g), high-rate capability (charge-discharge profiles at 20 A/g), and excellent cycle stability (96.86 % retention after 1000 cycles) in KOH electrolyte (6 M). Moreover, N-PCM-900 simultaneously provided high CO 2 adsorption ability (4.63 mmol/g) at 273 K, and high ideal adsorption solution theoretical value (25) for capturing CO 2 /N 2 at 298 K. The multifunctional porous carbon presented herein exhibited great potential for electrochemical energy storage and gas adsorption/separation. • A self-templated and solvent-free assembly approach was developed for the synthesis of hierarchical N-doped porous carbon. • The samples exhibited the structural features of high pore volume (1.75 m 3 g) and large specific surface area (3133 m 2 g). • High specific capacitance (161 F/g) and stability (99.4 % after 1000 cycles) are obtained. • Excellent CO 2 adsorption capacity (4.21 mmol/g) at 273 K and IAST selectivity (25) are gave.