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The rational structure design of the electrode materials is critical to achieve high-performance supercapacitors. In this contribution, a structure of carbon-coated MnCO3@MnO2 (MnCO3@MnO2@C) hierarchical hollow nanostructures is obtained through redox reaction on the basis of Kirkendall effect. The hollow structure and the coating of carbon layer provides a space and utilization rate of materials for charge storage in electrochemical energy storage. The electrode demonstrates an electrochemical performance with a specific capacitance of 267 F g−1 and a retention rate of 83.6% after 8000 cycles at 1A g−1. When the MnCO3@MnO2@C is used as positive electrode combined with hollow carbon sphere as the negative electrode, the assembled asymmetric supercapacitor displays a power density of 3840 Wkg−1 and energy density of 21.3 Wh kg−1, 78.2% of capacitance retention after 5000 cycles at 2 A g–1.

Nitrogen-doped cellulose-based porous carbon materials were obtained by hydrothermal method and KOH chemical activation together with melamine as a nitrogen-doping precursor. The effects of hydrothermal temperature on the microstructure and surface morphology of the products were mainly studied. Also, the carbon dioxide adsorption capacity of the prepared porous carbon was investigated. It was found that when the hydrothermal carbonization temperature was 270 °C and the mass ratio of cellulose and melamine was 1:1, the largest micropore specific surface area of 1703 m2·g-1 and micropore volume of 0.65 cm3·g-1 were obtained, with a nitrogen-doping composition of 1.68 atom %. At the temperature of 25 °C and under the pressure of 0.1, 0.2, 0.3, and 0.4 MPa, the adsorption amount of CO2 was 1.56, 3.79, 5.42, and 7.34 mmol·g-1, respectively. Also, the adsorption process of CO2 was in good accordance with the Freundlich isotherm model.

Lithium-sulfur batteries (LSBs) are deemed as one of the most promising next generation energy storage system substitutes for conventional lithium ion batteries due to their high energy density, low cost, and environmental friendliness. The practical application of LSBs has long been blocked by the serious lithium polysulfide (LiPS) shuttle effect and notorious Li dendrite growth, inducing fast capacity decay and limited cycling lifespan. Herein, fluorinated carbon prepared via a safe and scalable strategy has rationally been coated on a separator affording bifunctional fluorinated Celgard (F-Celgard) for LSB construction. The F-Celgard shows superior Li+ flux modulation and LiPS trapping capability, which has been verified by the density function theory calculations. The Li symmetric cells demonstrate long and stable Li plating/stripping with much smaller polarization voltage and dendrite-free Li deposition. In addition, LSBs show superior rate performances with higher discharge capacities and long-time stable cycling over 1000 cycles at 1 C with a low decay rate of ∼0.038% per cycle. With a high sulfur loading (∼5.2 mg cm-2), a high initial areal capacity of ∼4.2 mAh cm-2 can be obtained with a superior capacity retention of ∼91.8% at 0.2 C. This work demonstrates a facile, cost-effective, and scalable strategy toward highly stable LSBs for practical usage.

The integrity and stability of salt caverns for natural gas storage are subjected to a gas cycling loading operation. The coupled effect of confining pressure and temperature on the response of the salt cavity surrounding the wall is essential to stability analysis. In this study, a hybrid continuum-discrete model accounting for the thermal-mechanical process is proposed to investigate the thermal-damage evolution mechanism towards a field case with blocks falling off the salt cavity. The salt cavity is modeled by continuum zones, and the potential damage zones are simulated by discrete particles. Three specimens at different locations around the surrounding wall are compared in the context of severe depressurization. The dynamic responses of rock salt, including temperature spatiotemporal variation, microscopic cracking patterns, and energy evolution exhibit spatial and confinement dependence. A series of numerical simulations were conducted to study the influence of microproperties and thermal properties. It is shown that the evolution of cracks is controlled by (1) the thermal-mechanical process (i.e., depressurization and retention at low pressure) and (2) the anomalous zone close to the brim of the salt cavity surrounding the wall. The zone far away from the marginal surrounding wall is less affected by temperature, and only the mechanical conditions control the development of cracks. This continuum/discontinuum approach provides an alternative method to investigate the progressive thermal damage and its microscopic mechanism.

A three-dimensional vertical-aligned graphene-polydopamine electrode (PDA@3DVAG) composite with vertical channels and conductive network is prepared by a method of unidirectional freezing and subsequent self-polymerization. When the prepared PDA@3DVAG is constructed as the positive electrode of zinc-ion hybrid supercapacitors (ZHSCs), excellent electrochemical performances are obtained. Compared with the conventional electrolyte, PDA@3DVAG composite electrode in highly concentrated salt electrolyte exhibits better multiplicity performance (48.92% at a current density of 3 A g−1), wider voltage window (−0.8~0.8 V), better cycle performance with specific capacitance from 96.7 to 59.8 F g−1, and higher energy density (46.14 Wh kg−1).

Three-dimensional vertically aligned graphene (3DVAG) was prepared by a unidirectional freezing method, and its electrochemical performances were evaluated as electrode materials for zinc−ion hybrid supercapacitors (ZHSCs). The prepared 3DVAG has a vertically ordered channel structure with a diameter of about 20−30 μm and a length stretching about hundreds of microns. Compared with the random structure of reduced graphene oxide (3DrGO), the vertical structure of 3DVAG in a three−electrode system showed higher specific capacitance, faster ion diffusion, and better rate performance. The specific capacitance of 3DVAG reached 66.6 F·g−1 and the rate performance reached 92.2%. The constructed 3DVAG zinc−ion hybrid supercapacitor also showed excellent electrochemical performance. It showed good capacitance retention up to 94.6% after 3000 cycles at the current density of 2 A·g−1.

The reactivity index of weight loss (RI) and tumbling strength after the reaction (I10600) of manufacturing coke were first tested at a temperature series of 1100, 1200, and 1300 °C under CO2 atmosphere with different compositions and duration times to study the effects of temperature, time, and gas composition on coke hot strength. Then the RI/I10600, carbon structure, and optical texture of the cokes prepared from different single coals were mainly studied after a solution reaction with CO2 under a high temperature of 1300 °C and a standard temperature of 1100 °C. It was found that temperature greatly affects the RI/I10600 of coke, especially at high temperatures up to 1300 °C. Compared with standard tests under 1100 °C, the changes of RI/I10600 for different cokes are very different at 1300 °C, and the changes are greatly related to coke optical texture. Under a high temperature in the testing method, the tumbling strength of cokes with more isotropy increased, whereas it decreased for those with less isotropy. This simple method of using high temperature could yield the same results when compared with complicated simulated blast furnace conditions.

The reactivity and tumbler strength after reaction of cokes made from coals of different ranks and different regions of the world were tested under standard and simulated blast furnace (BF) conditions. The composition of coke optical textures and reactivity of different textures were investigated. It was found that reactivity and tumbler strength (I10600) after reaction of cokes are strongly related to the optical texture. For most cokes containing large amounts of isotropic textures, the reactivity index (RI) tested under simulated BF conditions is lower than CRI tested under standard conditions, and the I10600 under simulated BF conditions is higher than CSR under standard conditions. The reactivity of isotropic textures in most cokes is appreciably higher than that of anisotropic textures under standard conditions. Under simulated BF conditions, however, the reactivity of isotropic textures decreases significantly and the reactivity of anisotropic textures increases for the most part. This leads to narrowing the reactivity gap between isotropic and anisotropic textures.

Polyetheramine (D230), an epoxy curing agent, was grafted on graphene oxide (GO) surfaces, which can be stably dispersed in a waterborne curing agent for more than 8 months. Waterborne epoxy coatings reinforced by D230-functionalized GO (DGO) were prepared on carbon steel surfaces. According to the electrochemical impedance spectra, the impedance modulus at 0.1 Hz remained at 2.2 × 109 Ω after 150 days of immersion in 3.5% NaCl electrolytes for 0.2 wt% DGO-reinforced waterborne epoxy coatings, while that of the neat epoxy coatings dropped below 1 × 107 Ω after 10 days. Besides, the addition of DGO enhanced the weathering resistance of waterborne epoxy coatings. After 60 days of the UV aging test, the yellow color index of neat epoxy coatings was 1.6 times that of 0.5 wt% DGO/epoxy coatings. The residual pencil hardness of the 0.5 wt% DGO/epoxy coatings was three levels higher than that of neat epoxy coatings.

Encapsulation of linseed oil, a self-healing agent, in graphene oxide reinforced PAN shells was realized by coaxial electrospinning. The electrospun fibres were embedded in waterborne polyurethane coatings to prepare self-healing coatings. When cracks/microcracks occurred and caused the rupture of the core-shell fibres, the core material, linseed oil, would be released and filled in the cracks. Linseed oil will react with oxygen and solidify, so that the cracks/microcracks can be healed autonomously. The addition of graphene oxide in the PAN shells increased the thermal stability of the shells. The thickness of the fibre shells was 30–50 nm, suggesting that the microcracks in submicron-scale may trigger the self-healing process. The loading capacity of the fibres was about 45 wt%. The self-healing properties of the waterborne polyurethane coatings were improved with increasing content of the core-shell fibres.

Self-healing microcapsules were filled with a glue-like chemical that can repair damage and recover the original functions of materials. Graphene oxide (GO) was employed as the stabilizer of Pickering emulsions, and then the microcapsule shells were built upon the self-assembly of GO at oil/water interfaces. Linseed oil was encapsulated in the microcapsules as the healing agent. Several important factors were studied that affected the stabilization of the Pickering emulsions and the formation of the integral microcapsules, such as the pH value of GO aqueous solution, the GO/linseed oil mass ratio and the effect of surfactant. Chemical stitching of GO sheets by polyetheramine molecules were employed to enhance the chemical stability of the microcapsules. The waterborne polyurethane (PU) composite coatings containing 10 wt% microcapsules autonomously healed a scratch with 20 μm in width. After healing, the impedance modulus of the composite coatings was four orders of magnitude higher than neat PU.

An IGBT reliability model based on Saber software which can reflect the aging process of IGBT is proposed in this research in order to better reflect the changes of multi-feature values in IGBT reliability model. At first, the coupling relationship among electrical, thermal and mechanical of IGBT is deeply analyzed, and then an IGBT reliability evaluation model based on Saber software is established according to the failure mechanism of IGBT bond line, and its static and dynamic characteristics are verified. The simulation results are in good agreement with the experimental results. The effects of collector current $I_{c}$ and gate driving voltage $U_{ge}$ on the saturation voltage drop of IGBT are verified by the built model. The conclusions are as follows: 1) the saturation voltage drop increases continuously with the deepening of the aging degree of IGBT. 2) the saturation voltage drop is affected by the collector current and driving voltage passing through IGBT. The study of this model has a certain guiding significance for realizing the reliability evaluation of IGBT and improving the reliability of power electronic power conversion devices.

The temperature field distribution of IGBT module will be inevitably affected by the unavoidable void of solder layer in IGBT module packaging, which will seriously affect the thermal stability. In order to reduce the influence of the void in the encapsulation of IGBT module, the IGBT failure process is analyzed based on ANSYS. In this paper, a three-dimensional model of the IGBT module is established. Then, the influence of solder layer void on the temperature distribution of IGBT module under different sizes and positions is studied based on ANSYS. The results show that under the same void ratio, the void on the top corner of the solder layer has the greatest impact on the junction temperature of the IGBT module. Besides, at the same position, the maximum junction temperature of the IGBT module increases linearly with the increase of the void ratio on the solder layer. The simulation results have guiding significance for improving the thermal stability of IGBT modules.

Polyacrylonitrile (PAN)-based porous carbon was prepared by different methods of activation with PAN polymer microsphere as precursor. The morphology, structure and electrical properties for supercapacitor of the porous carbon were investigated. It was found that the morphology of PAN nanospheres tended to be destroyed in the process of one-step activation (activation and carbonization were carried out simultaneously, and could only be retained when the amount of activating agent KOH was small). While the spherical morphology could be well reserved during the two-step activation method (carbonization and activation sequentially). The specific surface area and pore volume increased first and then decreased, with the increase in activation holding time for both one-step and two-step activation methods. The specific surface area reached the maximum value with 2430 m2 g−1 for the one-step activation method and 2830 m2 g−1 for the two-step activation method. Additionally, their mass-specific capacitances were 178.8 F g−1 and 160.2 F g−1, respectively, under the current density of 1 A g−1. After 2000 cycles, the specific capacitance retentions were 92.9% and 91.3%.

Noise-induced-hearing-loss(NIHL) is a common occupational disease caused by various environmental and biological factors. To investigate the association between TAB2 and the susceptibility of NIHL of people exposed to occupational environments, a genetic association study was performed on selected companies with 588 cases and 537 healthy control subjects. Five selected single nucleotide polymorphisms (SNPs) in TAB2,incoluding rs2744434, rs521845, rs652921, rs7896, rs9485372, were genotyped after a collection of DNA samples. Evident differences in participants between the case group and the control group reveals the result that people with the TAB2 has a high probability of getting NIHL. The results show that rs521845 is deeply associated with the risk of NIHL and is available for the diagnosis in the future.

Noise-induced hearing loss (NIHL) is one of these hazards which has been the second most common sensorineural hearing loss. Single-nucleotide polymorphisms (SNPs) mainly refer to the polymorphism of DNA sequence caused by the variation at the genomic nucleotide level. The influence of histone deacetylase 2 (HDAC2) variants on the risk of NIHL has not been studied. This research explored the association between HDAC2 and the development of NIHL. A total of 1146 industrial workers from one textile factory in east China were recruited to perform a case-control study. Basic clinical data such sex, age, smoking, and drinking was obtained by questionnaires; pure-toneaudiometry (PTA) tests were conducted by specialist physicians. Then, we performed genotyping of five selected SNPs (rs10499080, rs2475631, rs2499618, rs6568819, and rs3757016) in the HDAC2 gene in 600 NIHL patients and 546 controls. Finally, the main influences of the SNPs and their interactions with NIHL were assessed. Under the recessive model, there were statistically significant differences in the genotype frequencies of rs10499080 between two groups, and the results showed that individuals with rs10499080 CC+CT had a lower risk of NIHL (OR = 0.597, 95%CI = 0.357-0.998). Meanwhile, the significant difference in the genotype distributions between cases and controls was found in rs10499080 in the group with noise exposure of ≤ 16 years. But the following haplotype analysis showed that no association between all haplotypes in the HDAC2 gene and NIHL was been found. The genetic polymorphisms rs10499080 and rs6568819 within HDAC2 gene have an association with risk of NIHL. Workers exposed to noise with HDAC2 have a lower risk of NIHL.

Objective To investigate the characteristics of workers with occupational benzene poisoning in Jiangsu Province during 2006-2018, find out the susceptible population of occupational benzene poisoning and provide some evidence for establishing some exposure standards for workers. Methods Questionnaire is the tool that we adopt to collect basic information of workers. Benzene detector is applied to detect the concentration of benzene in the working environments. Statistical description and analysis was conducted to analyze the prevalence of occupational benzene poisoning in Jiangsu Province during 2006-2018. Results The number of cases of occupational benzene poisoning in these years was 145, and 28 of them were diagnosed with benzene induced leukemia; the patients mainly worked in manufacturing industry（89.7%）; most of cases were distributed in small factories（43.4%） and private companies（46.2%）. Male workers took a major part in the cases of acute benzene poisoning（80%）while female workers had a higher proportion of the chronic benzene poisoning（65%）. Most cases were distributed in the 30-49 age group( 80%). There was no evident differences among these seniority groups, most of the cases were in the working age of 1-19 years old（82.9%）; concentration of benzene of chronic benzene poisoning workers were mostly under 0.6mg/m³（40%）. Conclusions The departments of occupational disease prevention should heighten the benzene surveillance of small-scale private companies in manufacturing industry, regular physical examination and health education should be conducted in the workers of low concentration of benzene exposure, safety protection measures should be taken to reduce the incidence of occupational poisoning.

Graphene derivatives can function as a barrier reinforcement in waterborne epoxy (WEP) coatings. The main challenge lies in the demulsification of epoxy emulsions caused by the addition of graphene derivatives and the dispersion of graphene sheets with a relatively high filler content. Herein, sulfonic acid groups were grafted on the edges of graphene sheets. The sulfonated graphene (SG) can be stably dispersed in water and waterborne epoxy emulsions, while graphene oxide (GO) caused demulsification of epoxy emulsions. Assembly of SG sheets at oil/water interfaces in WEP emulsions was proposed, which co-stabilized the WEP emulsions. SG reinforced WEP coatings were fabricated on carbon steel plates for corrosion protection. When the SG content was 0.2 wt%, SG sheets were nanoscopically well dispersed in WEP coatings. With the increase of the SG content, the SG sheets tended to assemble parallelly in short ranges, leaving a distance of 20–30 nm between the neighboring sheets. The corrosion protection properties of the coatings were significantly improved by the dispersed SG sheets, as well as the parallelly assembled SG sheets. The most remarkable improvement was achieved by adding 1.0 wt% SG into the WEP coatings, where the impedance modulus at 0.1 Hz was 193 times higher than that of the neat WEP coatings after 150 days of immersion in electrolytes. The outstanding corrosion protection properties were attributed to the stable WEP emulsions, the physical barrier properties of SG, the high SG content, and the sufficient distance between the parallelly assembled SG.

A large number of space-to-earth observation results show that there is a clear correlation between the space electromagnetic disturbances and the occurrence of earthquakes. So, the application of satellite to capture electromagnetic precursors is one of the most effective means of short-term and impending earthquake prediction, which promotes the development of electromagnetic seismic satellites. Some countries have carried out satellite observations of space electromagnetic phenomena one after another. The phenomena of space electromagnetic anomalies observed before the earthquake were reported. In recent years, the international electromagnetic seismic satellite project mainly includes: PREDVESTNIK-E, COMPASS-II, QUAKESAT, DEMETER, etc. In this paper, the current status of the international electromagnetic seismic satellites in orbit is investigated. The management mission characteristics of electromagnetic seismic satellites are analyzed and summarized. The development plan of satellite projects in the field of electromagnetic earthquake monitoring is investigated. The development trend of satellite application in earthquake disaster monitoring is prospected.

Corrosion protection coatings with autonomous early-warning functions can prevent catastrophic failure of steel structures. We prepared a self-sensing polymer composite coating with functionalized graphene oxide . The graphene oxide (GO) was chemically modified with 1, 10-phenanthroline-5-amine (phen), which can form a red complex with Fe 2+ , so as to give a signal of corrosion reaction at very early stage. The waterborne polyurethane (PU) was employed as the environmental-friendly coating matrix. The dispersion of the phen-modified GO in the PU matrix was promoted by the addition of laponite RD. The composite coatings with functionalization GO and laponite RD showed higher corrosion resistance than the pure PU coatings, as characterized by salt spray test. Before the accumulation of Fe 3+ on the steel plates, the red color change was observed for the composite coatings, showing the onset of the corrosion reaction.

Gieseler fluidity characterization is an important method to evaluate the fluidity of coal which highly influences the cohesive properties of coke formation. A concept of fluidity-temperature area SlgF instead of maximum fluidity lgMF was put forward to be used as the index of Gieseler fluidity characterization. Thirty-five coal samples were tested by Gieseler characterization and the sensitivity for identifying coal cohesiveness by SlgF and lgMF were compared. It was found that SlgF has a more sensitive resolution of coal fluidity than lgMF and it could give a correct result for judging coal cohesiveness in accordance with the comprehensive cohesiveness in most cases, especially for coals having almost same lgMF values.

In this paper, zwitterionic graphene oxide (ZGO) was prepared with two silanes. It was evident that the silane molecules were grafted on GO surfaces by covalent bondings. ζ potential of ZGO varied from −29.0 mV to +28.5 mV when the pH of the aqueous solution was changed from 12 to 2. As a result, the ZGO can be dispersed in both anionic and cationic waterborne polymer matrix. Besides, ZGO can be used as two-dimensional surfactant in a wider range of pH values than GO. The multi-applications of ZGO were enabled by the unique pH-responsive charge-conversion properties and pH-insusceptible amphiphilicity.

Nanoscale drug depots, comprising a drug reservoir surrounded by a carrier membrane, are much sought after in contemporary pharmaceutical research. Using cellulose acetate (CA) as a filament-forming polymeric matrix and ferulic acid (FA) as a model drug, nanoscale drug depots in the form of core-shell fibers were designed and fabricated using a modified tri-axial electrospinning process. This employed a solvent mixture as the outer working fluid, as a result of which a robust and continuous preparation process could be achieved. The fiber-based depots had a linear morphology, smooth surfaces, and an average diameter of 0.62 ± 0.07 μm. Electron microscopy data showed them to have clear core-shell structures, with the FA encapsulated inside a CA shell. X-ray diffraction and IR spectroscopy results verified that FA was present in the crystalline physical form. In vitro dissolution tests revealed that the fibers were able to provide close to zero-order release over 36 h, with no initial burst release and minimal tailing-off. The release properties of the depot systems were much improved over monolithic CA/FA fibers, which exhibited a significant burst release and also considerable tailing-off at the end of the release experiment. Here we thus demonstrate the concept of using modified tri-axial electrospinning to design and develop new types of heterogeneous nanoscale biomaterials. Statement of Significance Nanoscale drug depots with a drug reservoir surrounded by a carrier are highly attractive in biomedicine. A cellulose acetate based drug depot was investigated in detail, starting with the design of the nanostructure, and moving through its fabrication using a modified tri-axial electrospinning process and a series of characterizations. The core-shell fiber-based drug depots can provide a more sustained release profile with no initial burst effect and less tailing-off than equivalent monolithic drug-loaded fibers. The drug release mechanisms are also distinct in the two systems. This proof-of-concept work can be further expanded to conceive a series of new structural biomaterials with improved or new functional performance.

The selection of proper electrode materials and the design of rational structure are two efficient approaches to improve the electrochemical performance of supercapacitors. Carbonaceous materials have become an important choice of electrode materials due to their good electrical conductivity and accommodation for volume expansion of metal oxides. In this contribution, hollow double-shell structured H-SnO2/MesCHS (mesoporous carbon hollow spheres) heterostructure is successfully achieved by silica template and in-situ polymerization methods. The H-SnO2/MesCHS composites demonstrate a specific surface area of 747.7 m2 g-1 and an average pore size of ca. 4.9 nm in the mesoporous carbon shell, where the outer layer of mesoporous hollow carbon layer act as a buffer to confine the volume expansion of the inner hollow tin oxide sphere. As consequence, hollow double-shell H-SnO2/MesCHS heterostructure demonstrates an excellent electrochemical performance with a high specific capacitance of 470 F g-1, exceptional cycling stability (88.4% retention of capacitance over 4000 cycles) and outstanding coulombic efficiency of 86.5% at high current density of 20 A g−1. The work provides an alternative route for the preparation of spherical hollow heterostructures materials with tunable double shell architectures, which may potentially be used as electrode materials for high-performance of energy storage.

In this study, a fast and simple method for highly sensitive detection of Cd and Pb elements based on atmospheric pressure glow discharge atomic emission spectrometry (APGD-AES) coupling with tungsten coil electrothermal vaporization (ETV) was proposed. A small amount of sample (10 μL) was dropped onto the tungsten coil, followed by drying, pyrolysis and vaporization procedures, and then the vaporized analyte was transported to APGD for excitation. The whole procedure took approximately 3 min. Multi-step heating of the ETV unit can separate matrices and solvents from the analyte, providing an advantage in detecting samples with complex matrix. Under the optimal experimental conditions, limits of detection of 0.4 μg L−1 (4 pg) for cadmium and 1.2 μg L−1 (12 pg) for lead were obtained, with relative standard deviations of 20 μg L−1 Cd and 100 μg L−1 Pb both being

Natural microcrystalline graphite (MG), which shows highly graphitized structure and near-isotropic material properties, can be used as filler material in isotropic graphite preparation. The final properties of graphite artifacts are largely determined by the interaction between pitch and filler particles during kneading. To achieve a better understanding of the wetting mechanism of MG filler, wetting behavior of pitch on substrates with different crystal structures was studied by measuring their contact angles. The results showed that both crystalline orientation and degree of graphitization of substrates could significantly influence the pitch wettability. Edge planes of graphite surface showed better wetting capacity than basal planes. And cokes obtained at very high temperature with highly graphitized structure tended to prevent pitch from wetting. Further wetting test showed that MG substrate was totally wetted by pitch drop, and its wetting time was shorter than coke. The wetting behavior of MG was related to its unique crystalline structure and surface morphology, and beneficial to the mechanical strength of MG-based isotropic graphite.

Three-dimensional beehive-like hierarchical porous carbons (HPCs) have been prepared by a facile carbonization of polymethylmethacrylate (PMMA)/polyacrylonitrile (PAN) core-shell polymer particle followed by KOH activation. The all-organic porogenic core-shell precursor was synthesized by a simple and green surfactant-free emulsion polymerization. The as-obtained HPCs show favorable features for electrochemical energy storage such as high specific surface area of up to 2085 m 2 g −1 , high volume of pores up to 1.89 cm 3 g −1 , hierarchical porosity consisting of micro, meso, and macropores, turbostratic carbon structure, uniform pore size and rich oxygen-doping (21.20%). The supercapacitor performance of HPCs exhibit a high specific capacitance 314 F g −1 at a current density of 0.5 A g −1 and 237 F g −1 at a current density of 20 A g −1 , ultra-high rate capability with 83% retention rate from 1 to 20 A g −1 and outstanding cycling stability with 96% capacitance retention after 2000 cycles. The facile, efficient and green synthesis strategy for novel HPCs from polymer sources could find use in supercapacitors, lithium ion batteries, fuel cells and sorbents.