A simple one step activation method is used to achieve an ultra-high specific surface area of 2943 m2 g−1, and abundant pore volume of 1.83 cm3 g−1 with a rational micro/meso/macro pore size ...distributed activated carbon nanosheets from Prosopis Juliflora wood carbon waste blocks. A superior electrochemical performance has been achieved with a specific capacitance of 588 F g-1 at 0.5 A g−1 with an excellent stability (retention 92.5% after 6000 cycles) in 6 M KOH electrolyte for a three-electrode approach. The assembled symmetric supercapacitor device outperformed in a neutral aqueous electrolyte compared to an alkaline electrolyte, such as with a gravimetric capacitance of 403 and 426 F g−1 and superior energy density of 32.9 W h kg−1 (at 172.7 W kg−1) and 56.7 W h kg−1 (at 248.8 W kg−1), and a large electrochemical window of 0–1.4 V in 6 M KOH and 0–2 V in 1 M Na2SO4 electrolyte, respectively. The electrochemical performance has been enhanced by the degree of graphitization, surface functional groups, surface area and pore structure/volume. This work provides a trustworthy approach to produce higher energy density devices from renewable biomass carbon wastes for various energy storage applications.
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•Turning trash into treasure, the preparation of unique 3D porous carbon derived out of the evillest wood.•ACN exhibits high SSA of 2943 m2 g-1 & pore volume of 1.83 cm3 g-1 responsible for high charge storage.•The A.C.N-900 exhibited high specific capacitance of 588 F g−1 & high cyclic stability.•In neutral electrolyte, the Fabricated symmetric SC delivered a remarkable energy density of 56.3 Wh Kg−1 at 249 W kg−1.
ZnCo2O4 (ZC-UAH) nanomaterials fabricated using an essential-route hydrothermal technique followed by a post-annealing procedure and used as the materials for high performance supercapacitors (SCs) ...by varying three reagents: urea (UA), ammonium fluoride (AF), and hexamethylenetetramine (HT). A reagent composite (ZC-UAH) served as a large surface area, high electrical conductivity, growth modifier during fabrication, and provide active abundant active sites for Faradaic redox reactions. The resulting products of the crystalline structural, composition, morphological, surface analysis behaviors were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, and Brunauer-Emmett-Teller analysis. The electrochemical properties of the as-prepared materials were tested using a three-electrode system. As a result, the reagent-assisted composite of the ZC-UAH electrode material showed a higher specific capacity of 462.5C g−1 at a current density of 1 A g−1 within the potential range of 0.0–0.4 V in the 2 M KOH electrolyte solution. In addition, the ZC-UAH composite delivered excellent cycling stability, retaining 97.4% of its initial capacitance after 5000 cycles. These outcomes show that the reagent-assisted composite of the ZC-UAH electrode material has remarkable application potential and can achieve better characteristics for high-performance supercapacitors in energy storage applications.
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•ZnCo2O4 (ZC-UAH) composite has been designed by various active precursors.•ZC-UAH-based supercapacitor can afforded rich active sites for redox reactions.•ZC-UAH-based supercapacitor showed excellent electrochemical activities.•ZC-UAH-based supercapacitor showed excellent cyclability.
Well-ordered, unique interconnected nanostructured binary metal oxides with lightweight, free-standing, and highly flexible nickel foam substrate electrodes have attracted tremendous research ...attention for high performance supercapacitor applications owing to the combination of the improved electrical conductivity and highly efficient electron and ion transport channels. In this study, a unique interconnected nanoplate-like nickel cobaltite (NiCo
O
) nanostructure was synthesized on highly conductive nickel foam and its use as a binder-free material in energy storage applications was assessed. The nanoplate-like NiCo
O
nanostructure electrode was prepared by a simple chemical bath deposition method under optimized conditions. The NiCo
O
electrode delivered an outstanding specific capacitance of 2791 F g
at a current density of 5 A g
in a KOH electrolyte in a three-electrode system as well as outstanding cycling stability with 99.1% retention after 3000 cycles at a current density of 7 A g
. The as-synthesized NiCo
O
electrode had a maximum energy density of 63.8 W h kg
and exhibited an outstanding high power density of approximately 654 W h kg
. This paper reports a simple and cost-effective process for the synthesis of flexible high performance devices that may inspire new ideas for energy storage applications.
Energy storage system (ESS) technology is still the logjam for the electric vehicle (EV) industry. Lithium-ion (Li-ion) batteries have attracted considerable attention in the EV industry owing to ...their high energy density, lifespan, nominal voltage, power density, and cost. In EVs, a smart battery management system (BMS) is one of the essential components; it not only measures the states of battery accurately, but also ensures safe operation and prolongs the battery life. The accurate estimation of the state of charge (SOC) of a Li-ion battery is a very challenging task because the Li-ion battery is a highly time variant, non-linear, and complex electrochemical system. This paper explains the workings of a Li-ion battery, provides the main features of a smart BMS, and comprehensively reviews its SOC estimation methods. These SOC estimation methods have been classified into four main categories depending on their nature. A critical explanation, including their merits, limitations, and their estimation errors from other studies, is provided. Some recommendations depending on the development of technology are suggested to improve the online estimation.
The amount of distributed energy resources (DERs) has increased constantly worldwide. The power ratings of DERs have become considerably high, as required by the new grid code requirement. To follow ...the grid code and optimize the function of grid-connected inverters based on DERs, a phase-locked loop (PLL) is essential for detecting the grid phase angle accurately when the grid voltage is polluted by harmonics and imbalance. This paper proposes a novel low-pass notch filter PLL (LPN-PLL) control strategy to synchronize with the true phase angle of the grid instead of using a conventional synchronous reference frame PLL (SRF-PLL), which requires a d-q-axis transformation of three-phase voltage and a proportional-integral controller. The proposed LPN-PLL is an upgraded version of the PLL method using the fast Fourier transform concept (FFT-PLL) which is robust to the harmonics and imbalance of the grid voltage. The proposed PLL algorithm was compared with conventional SRF-PLL and FFT-PLL and was implemented digitally using a digital signal processor TMS320F28335. A 10-kW three-phase grid-connected inverter was set, and a verification experiment was performed, showing the high performance and robustness of the proposal under low-voltage ride-through operation.
Cytomegalovirus (CMV) infection after hematopoietic stem cell transplantation (HSCT) is one of the critical infectious complications related to host immune recovery. The spectrum of CMV infection is ...quite extensive, from asymptomatic CMV reactivation presenting mainly as CMV DNAemia to fatal CMV diseases involving gut, liver, lungs, or brain. In addition to organ involvement, CMV reactivation can exert indirect effects such as immunosuppression or graft failure that may result in the development of concurrent infectious complications. Currently, preemptive therapy, which is based on PCR-based monitoring of CMV from blood, is a mainstay enabling improvement in CMV-related outcomes. During the past decades, new antiviral drugs, clinical trials for prophylaxis in high-risk groups, and vaccines for preventing CMV infection have been introduced. In addition, data for immunologic monitoring and adoptive immunotherapy have also been accumulated. Here, we review the current status and recent updates in this field, with future perspectives including immunotherapy in HSCT recipients.
Manganese‐based electrocatalyst has a great attention for the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) applications, since the discovery of active centre in nature ...photosynthesis system. The Mn oxidation state optimization and structural defect engineering are essential to get a highly active Mn‐based catalytic materials. MnP showed a good water oxidation activity with a lower overpotential of 286 mV to reach the current density of 10 mA/cm2 and a Tafel slope of 76 mV/dec. Also, the electron transfer number calculated from both the rotating disk electrode and rotating ring‐disk electrode techniques is a quasi‐4 electron transfer process with an onset and halfwave potential of 0.998 V and 0.936 V vs RHE respectively. MnP achieved a higher limiting kinetic current of 5.7 mA/cm2 and a very low H2O2 yield of 1.6 %. Chronoamperometry and cyclic voltammetry studies confirmed the long‐term stability and durability of the prepared catalyst. The variance metrics ΔE Ej10−Ej‐3 is used to estimate the overall activity from the potential difference between OER overpotential at 10 mA/cm2 and ORR kinetic current at 3 mA/cm2. MnP shows very low ΔE (0.58 V) which demonstrate an efficient bifunctional activity in ORR and OER reactions. This work might shed new light on the development of MnP based bifunctional oxygen electrocatalyst.
Manganese‐based electrocatalyst: Manganese phosphate nano‐polyhedrons prepared by one step hydrothermal synthesis and its bifunctional oxygen electrocatalyst applications
Carbon nanotubes (CNT) and metal sulfides have attracted considerable attention owing to their outstanding properties and multiple application areas, such as electrochemical energy conversion and ...energy storage. Here we describes a cost-effective and facile solution approach to the preparation of metal sulfides (PbS, CuS, CoS, and NiS) grown directly on CNTs, such as CNT/PbS, CNT/CuS, CNT/CoS, and CNT/NiS flexible electrodes for quantum dot-sensitized solar cells (QDSSCs) and supercapacitors (SCs). X-ray photoelectron spectroscopy, X-ray diffraction, and transmission electron microscopy confirmed that the CNT network was covered with high-purity metal sulfide compounds. QDSSCs equipped with the CNT/NiS counter electrode (CE) showed an impressive energy conversion efficiency (η) of 6.41% and remarkable stability. Interestingly, the assembled symmetric CNT/NiS-based polysulfide SC device exhibited a maximal energy density of 35.39 W h kg
and superior cycling durability with 98.39% retention after 1,000 cycles compared to the other CNT/metal-sulfides. The elevated performance of the composites was attributed mainly to the good conductivity, high surface area with mesoporous structures and stability of the CNTs and the high electrocatalytic activity of the metal sulfides. Overall, the designed composite CNT/metal-sulfide electrodes offer an important guideline for the development of next level energy conversion and energy storage devices.
CoO–ZnO-based composites have attracted considerable attention for the development of energy storage devices because of their multifunctional characterization and ease of integration with existing ...components. This paper reports the synthesis of CoO@ZnO (CZ) nanostructures on Ni foam by the chemical bath deposition (CBD) method for facile and eco-friendly supercapacitor applications. The formation of a CoO@ZnO electrode functioned with cobalt, zinc, nickel and oxygen groups was confirmed by X-ray diffraction (XRD) analysis, X-ray photoelectron spectroscopy (XPS), low and high-resolution scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analysis. The as-synthesized hierarchical nanocorn skeleton-like structure of a CoO@ZnO-3h (CZ3h) electrode delivered a higher specific capacitance (Cs) of 1136 F/g at 3 A/g with outstanding cycling performance, showing 98.3% capacitance retention over 3000 cycles in an aqueous 2 M KOH electrolyte solution. This retention was significantly better than that of other prepared electrodes, such as CoO, ZnO, CoO@ZnO-1h (CZ1h), and CoO@ZnO-7h (CZ7h) (274 F/g, 383 F/g, 240 F/g and 537 F/g). This outstanding performance was attributed to the excellent surface morphology of CZ3h, which is responsible for the rapid electron/ion transfer between the electrolyte and the electrode surface area. The enhanced features of the CZ3h electrode highlight potential applications in high performance supercapacitors, solar cells, photocatalysis, and electrocatalysis.
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Developing cost-effective and efficient oxygen evolution reaction (OER) electrocatalyst is highly essential for energy-conversion technologies. A self-assembled NiFe-layered double ...hydroxide (LDH)@MnCO3 heterostructure prepared on Ni foam using a successive hydrothermal strategy shows notable catalytic activity toward the OER with a small overpotential of 275 mV to drive a geometrical current density of 10 mA cm−2 under alkaline conditions with remarkable stability for 15 h, outperforming IrO2/C electrocatalyst (350 mV@10 mA cm−2). The hierarchical NiFe-LDH@MnCO3 heterostructure possess more exposed active sites, enhanced conductivity and superior interfacial coupling effect makes them an ideal candidate for OER electrocatalyst.
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