The interlayer modification and the intercalation pseudocapacitance have been combined in vanadium oxide electrode for aqueous zinc-ion batteries. Intercalation pseudocapacitive hydrated vanadium oxide Mn 1.4 V 10 O 24 •12H 2 O with defective crystal structure, interlayer water, and large interlayer distance has been prepared by a spontaneous chemical synthesis method. The inserted Mn 2+ forms coordination bonds with the oxygen of the host material and strengthens the interaction between the layers, preventing damage to the structure. Combined with the experimental data and DFT calculation, it is found that Mn 2+ refines the structure stability, adjusts the electronic structure, and improves the conductivity of hydrated vanadium oxide. Also, Mn 2+ changes the migration path of Zn 2+ , reduces the migration barrier, and improves the rate performance. Therefore, Mn 2+ -inserted hydrated vanadium oxide electrode delivers a high specific capacity of 456 mAh g −1 at 0.2 A g -1 , 173 mAh g -1 at 40 A g -1 , and a capacity retention of 80% over 5000 cycles at 10 A g -1 . Furthermore, based on the calculated zinc ion mobility coefficient and Zn(H 2 O) n 2+ diffusion energy barrier, the possible migration behavior of Zn(H 2 O) n 2+ in vanadium oxide electrode has also been speculated, which will provide a new reference for understanding the migration behavior of hydrated zinc-ion.

Co3O4 has received ever-growing interest as an electro-active material for supercapacitors due to its high theoretical specific capacitance (3560 F g−1) and simple synthesis process.

3D petal-like NiCo2S4 nanostructures have been fabricated via a simple, mild and efficient hydrothermal strategy and the growth mechanism of NiCo2S4 nano-petals has been investigated.

Wearable textile energy storage systems are rapidly growing, but obtaining carbon fiber fabric electrodes with both high capacitances to provide a high energy density and mechanical strength to allow the material to be weaved or knitted into desired devices remains challenging. In this work, N/O‐enriched carbon cloth with a large surface area and the desired pore volume is fabricated. An electrochemical oxidation method is used to modify the surface chemistry through incorporation of electrochemical active functional groups to the carbon surface and to further increase the specific surface area and the pore volume of the carbon cloth. The resulting carbon cloth electrode presents excellent electrochemical properties, including ultrahigh areal capacitance with good rate ability and cycling stability. Furthermore, the fabricated symmetric supercapacitors with a 2 V stable voltage window deliver ultrahigh energy densities (6.8 mW h cm−3 for fiber‐shaped samples and 9.4 mW h cm−3 for fabric samples) and exhibit excellent flexibility. The fabric supercapacitors are further tested in a belt‐shaped device as a watchband to power an electronic watch for ≈9 h, in a heart‐shaped logo to supply power for ≈1 h and in a safety light that functions for ≈1 h, indicating various promising applications of these supercapacitors.

A new composite electrode design was successfully fabricated based on 3D flexible graphene foams (GF) with interconnected macropores as the freestanding substrate and a composite of MnO2 nanoparticles and polypyrrole (PPy) as an integrated electrode.

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Owing to a lack of electroactive sites and poor conductivity, Co oxides/hydroxides nanosheet network electrodes usually show low experimental capacity, hardly meeting the demand for high energy density needed for an asymmetric supercapacitor. Herein, we demonstrate a surface capacity enhancement of a 3D cobalt oxides/hydroxides nanosheet network cathode through a simple cyclic voltammetry electro-deposition method. By optimizing the electro-deposition parameters, the as-prepared Co oxides/hydroxides nanosheet network electrode delivers a significantly high capacity of 427 C g-1 at the current density of 1 A g-1 and excellent rate ability of 79.8% at the current density of 10 A g-1, as well as outstanding cycling life. A detailed voltammetric analysis using the power-law relationship and Trasatti's method shows that both the large surface area, high pore volume and polycrystalline nature contribute to the enhancement of the surface capacity. In addition, the assembled asymmetric all-solid-state supercapacitor also presents a volume energy density of 2.78 mW h cm-3 at a power density of 14 mW cm-3 and excellent cycling stability. In addition, our prepared asymmetric supercapacitor shows super flexibility and was used to light up a heart-shaped logo. This work may provide valuable insights into the design and fabrication of electrode materials with improved capacity and rate ability.