ASC Device Research Articles

Synthesis of Cu2O by oxidation-assisted dealloying method for flexible all-solid-state asymmetric supercapacitors

Supercapacitors are promising energy storage devices for flexible electronics because of their integration of lightweight, tiny volume and high flexibility. Here, a facile yet effective method was developed to synthesize Cu2O, by oxidation-assisted dealloying and subsequent electrochemical strategies. The assembled asymmetric supercapacitor device, using Cu2O as the positive electrode and active carbon as the negative electrode could be operated with high voltage region of 1.65 V and exhibited a high energy density of 20.04 Wh kg−1. Additionally, our device had an excellent long-term cycling stability with more than 93.3% retention after 5000 cycles. To demonstrate potential application of our prepared flexible all-solid-state ASC device, four charged devices were constructed in series, they were able to illuminate 52 red colored LEDs.

Fabrication of porous nanosheets assembled from NiCo2O4/NiO electrode for electrochemical energy storage application

In this work, The NiCo2O4/NiO electrode materials are successfully synthesized via hydrothermal and following calcination approach. Due to the distinctive porous nanosheets assembled structure through controlling effectively the feeding amount of HMT, the NiCo2O4/NiO electrode possesses excellent specific surface area and reasonable pore size distribution, which hence minimizes the intrinsic electrode resistance and improves the morphology and structure stability. Therefore, the NiCo2O4/NiO electrode delivers a superior specific capacitance (Csp) (992.85Fg−1 at the current density of 1Ag−1), good rate capability (79.14% Csp retention even at 10Ag−1) and considerable cycle life (79.82% Csp retention at 10Ag−1 after 5000 times). Furthermore, the asymmetric supercapacitor is successfully assembled by NCN-0.1 as positive electrode and activated carbon (AC) as negative electrode. The NCN-0.1//AC device delivers a relatively excellent energy density of 47.43kWkg−1 at a power density of 0.389Whkg−1. Consequently, the outstanding performance and stability of the ASC device shows great potential for future energy storage application.

Substrate-integrated core–shell Co3O4@Au@CuO hybrid nanowires as efficient cathode materials for high-performance asymmetric supercapacitors with excellent cycle life

Designing Co3O4@Au@CuO core–shell nanowire cathode for a high-performance α-Fe2O3//Co3O4@Au@CuO hybrid asymmetric supercapacitors (ASCs).

Electrostatic-Induced Assembly of Graphene-Encapsulated Carbon@Nickel-Aluminum Layered Double Hydroxide Core-Shell Spheres Hybrid Structure for High-Energy and High-Power-Density Asymmetric Supercapacitor.

Achieving high energy density while retaining high power density is difficult in electrical double-layer capacitors and in pseudocapacitors considering the origin of different charge storage mechanisms. Rational structural design became an appealing strategy in circumventing these trade-offs between energy and power densities. A hybrid structure consists of chemically converted graphene-encapsulated carbon@nickel-aluminum layered double hydroxide core-shell spheres as spacers among graphene layers (G-CLS) used as an advanced electrode to achieve high energy density while retaining high power density for high-performance supercapacitors. The merits of the proposed architecture are as follows: (1) CLS act as spacers to avoid the close restacking of graphene; (2) highly conductive carbon sphere and graphene preserve the mechanical integrity and improve the electrical conductivity of LDHs hybrid. Thus, the proposed hybrid structure can simultaneously achieve high electrical double-layer capacitance and pseudocapacitance resulting in the overall highly active electrode. The G-CLS electrode exhibited high specific capacitance (1710.5 F g-1 at 1 A g-1) under three-electrode tests. An ASC fabricated using the G-CLS as positive electrode and reduced graphite oxide as negative electrode demonstrated remarkable electrochemical performance. The ASC device operated at 1.4 V and delivered a high energy density of 35.5 Wh kg-1 at a 670.7 W kg-1 power density at 1 A g-1 with an excellent rate capability as well as a robust long-term cycling stability of up to 10 000 cycles.

High‐Performance Flexible Solid‐State Asymmetric Supercapacitors based on Ordered Mesoporous Cobalt Oxide

AbstractAsymmetric supercapacitors (ASCs) have attracted growing interest and attention in the field of supercapacitors owing to their high energy density and power density. In this work, ordered mesoporous Co3O4 samples with different pore sizes (ca. 20 nm and ca. 70 nm) are prepared via a hard template method. Flexible solid‐state ASC devices based on mesoporous Co3O4 with pore size of 20 nm and activated carbon possesses a specific capacitance of 215 mF cm−2 (at 1.5 mA cm−2) and show excellent cycling performance. Electrochemical tests reveal that the mesoporous material with a larger specific surface area, that is, a smaller primary particle size, is more suitable for solid‐state ASC device. The results provide a potential electrode material for ACSs.

Successful Use of a Left Ventricular Apical Access and Closure Device for Second-Generation Transapical Aortic Valve Implantation

Transcatheter aortic valve implantation (TAVI) has become routine for the treatment of high-risk patients with aortic stenosis. We assessed safety and feasibility of a left ventricular apical access and closure device combined with second-generation transapical (TA) TAVI transcatheter heart valves (THV). Three elderly, comorbid patients (logEuroSCORE I 13.0-31.1%) received transapical aortic valve implantation (TA-AVI) via the Apica ASC device (Apica Cardiovascular Ltd., Galway, Ireland) using second-generation THV (Medtronic Engager [Medtronic 3F Therapeutics, Santa Ana, California, United States], JenaValve [JenaValve Technology GmbH, Munich, Germany], Symetis Acurate [Symetis S.A., Ecublens, Switzerland]). Access was gained using a non-rib-spreading technique and a novel access and closure device. THV deployment was successful with excellent hemodynamic outcome (no PVL, n = 2; trace PVL, n = 1; mean transvalvular gradients, 5-19 mm Hg) and complete apical hemostasis. No periprocedural major adverse events occurred and Valve Academic Research Consortium-2-defined composite end point of device success was met in all cases. Safety and feasibility of TA-AVI using the ASC device with second-generation THV was demonstrated. Combining latest available technology is a major step toward improved functional outcome and decreased surgical trauma in TA-AVI. Potentially, technical enhancements may eventually pave the way toward a fully percutaneous TA-AVI procedure.

Experimental Evaluation of a New Apical Access and Closure Device

Transapical aortic valve implantation (TA-AVI) has evolved as a treatment option for high-risk patients who have severe aortic stenosis. The aim of this study was to evaluate the feasibility of a novel apical closure device to allow for standardized apical access and closure. The Apica ASC system consists of three components: an introducer system, a left ventricular low-profile titanium coil, and a closure cap. The ASC introducer system is fixed to the myocardium by anchoring the titanium coil into the epicardium. After the TA-AVI procedure, the closure cap is introduced through the system and delivered onto the titanium coil for final sealing. After sternotomy, fixation of the introducer system was successfully performed in an acute pig model. The apex was safely secured in all attempts, and the titanium coil created an effective seal around the Ascendra sheath. Finally, the closure cap was shown to be secure even when the hearts were pressurized to 200 mm Hg. Postmortem examination showed a uniform depth of the titanium coil through the endocardium into the myocardial wall without penetration into the left ventricular cavity. Apical access and closure is feasible using the sutureless Apica ASC device. The system seems to have the potential to further standardize the TA-AVI procedure, allowing wider applicability and more generalizability.