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We report the fabrication of sandwich-structured MnO 2 /graphene (MG) nanoflowers by an in situ chemical redox reaction between mesoporous carbon and KMnO 4 , which was characterized by various techniques. The results demonstrate that the mesoporous carbon was corroded into interconnected graphene framework with ultrathin MnO 2 nanofilms deposited simultaneously on both sides of the as-generated graphene sheets. The as-synthesized MG exhibits excellent supercapacitive behaviours in a wide potential window from −0.2 to 1.2 V vs. saturated calomel electrode with a 0.5 M aqueous Li 2 SO 4 solution as the electrolyte. Specially, the MG electrode delivers a reversible gravimetric capacitance of ∼240 F g −1 at 1 A g −1 for 1000 cycles with retention rate up to 96%. The significant synergistic efforts and structure hybridization contribute to such improved electrochemical properties, indicating that the MG hybrid holds great promise in the application of high-performance supercapacitors. [ABSTRACT FROM AUTHOR]

• 2D Mxene-Ti 3 C 2 intercalated ZnCo 2 O 4 nanowires have been successfully synthesized. • The introduction of Ti 3 C 2 accelerates the dynamics of electrochemical reactions. • An ASC exhibits high energy density and 90.5% capacity retention after 10,000 cycles. It is necessary to develop hierarchical structured materials with excellent electrochemical characteristics and stability for energy storage. In this work, we synthesize a novel structure of ZnCo 2 O 4 /Ti 3 C 2 on Ni foam by a simple hydrothermal method. The frameworks accelerates the kinetic of the electrochemical reaction and promotes the transfer of electrons. The cycling stability of the device maintains 108.2% after 4000 cycles. The result indicates that the prepared sample is an excellent candidate material for energy storage. [ABSTRACT FROM AUTHOR]

Here, we assembled a CuCo2-NSs/NiCo2S4 nano-flower clusters hetero-structured materials directly grown on nickel foam. The prepared material showed an extremely high capacitance of 3.10 F cm−2 with excellent reversibility. An important factor in achieving excellent performance is the heterogeneous structure. An asymmetric supercapacitor is constructed by placing CuCo2-NSs/NiCo2S4 and activated carbon electrodes parallel to each other. The asymmetric supercapacitor has a high energy density of 48.2 W h kg−1 at a power density of 245.0 W kg−1 and the capacity retention remains still 98.5% after 7000 cycles. [ABSTRACT FROM AUTHOR]

A lot of attention is being paid to developing new electrode materials for energy storage with good stability and excellent specific capacitance. This work involves hydrothermal and oxidation processes to grow NiCo2@PEDOT/PMo12 materials on carbon cloth. At 20 mA cm−2, the prepared electrodes show an extremely high capacitance of 3476 mF cm−2. The results prove that NiCo2, PEDOT, and PMo12 ternary components synergized to promote electron transport and electrolyte diffusion. The SC device presents a high energy density of 0.41 mW h cm−3 at a power density of 8.57 mW cm−3, and cycle stability test shows 108.1 % after 600 cycles and 74.5 % after 6000 cycles. In addition, the capacitance of the ASC device is smaller than that of the SC, but the device retains 101.4 % of its initial capacitanc after 10000 cycles at 2 mA cm−2. [ABSTRACT FROM AUTHOR]