Increasing numbers of flexible universal energy storage devices are required for wearable and portable products. A typical representation of energy storage devices are supercapacitors. However, their applications are greatly limited due to their low conductivity, which is strongly restricted by the effect of the binder. We designed and prepared a flexible and binder-free supercapacitor based on...

A simple electrophoretic deposition method was developed to prepare graphene oxide (GO) films on the frameworks of nickel foam without any conductive agents and polymer binders. Then, GO was transformed into thermally-reduced graphene oxide (RGO) at an appropriate temperature. The effects of deposition voltage and thermal reduction temperature on the electrochemical properties of RGO were inves...

In this study, we report a facile fabrication of ultrathin two-dimensional (2D) nanosheet hybrid composite, α-Fe2O3 nanosheet@Ni(OH)2 nanosheet, by a two-step hydrothermal method to achieve high specific capacitance and good stability performance at high charging/discharging rates when serving as electrode material of supercapacitors. The α-Fe2O3@Ni(OH)2 hybrid electrode not only has a smooth d...

Article history: Received 13 January 2014 Accepted 9 February 2014 Available online 13 February 2014 Two major issues of conventional supercapacitors, composed of a separator, two electrodes, and liquid electrolyte, are their low package energy density and the leakage of the liquid electrolyte. Therefore, great efforts have been dedicated in development of allsolid-state supercapacitors with hi...

Aligned CoF2 nanochannel layers have been formed by self-ordering electrochemical anodization. In voltammograms these layers provide multiple oxidation states, an almost ideal rectangular pseudocapacitive behavior, a high specific capacitance and good capacitance retention. These layers may thus be promising for supercapacitor applications.

Nano-aggregates of cobalt nickel oxysulfide (CoNi)OxSy have been synthesized by hydrothermal processing and exhibited specific and areal capacitance as high as 592 F g(-1) and 1628 mF cm(-2), respectively, at a current density of 0.5 A g(-1)/1.375 mA cm(-2). They also show high capacitance retention upon extended cycling at high rates.

In this paper modeling of capacitance and sensitivity for MEMS capacitive pressure sensor is presented. In capacitive sensor the sensitivity is proportional to deflection and capacitance changes versus pressure. Therefore first the diaphragm displacement, capacitance and sensitivity of sensor with square diaphragm have been modeled and then simulated using finite element method (FEM).  It can b...

EFFECT OF MESOPOROSITY ON SPECIFIC CAPACITANCE OF CARBONS J.A. Fernández , S. Tennison , O.Kozynchenko , F. Rubiera , F. Stoeckli , T.A. Centeno , a Instituto Nacional del Carbón-CSIC. Apartado 73, E-33080 Oviedo, Spain b MAST Carbon International Ltd., Henley Park, Guildford, Surrey, GU3 2AF, United Kingdom c Physics Department, University of Neuchâtel. Rue Emile Argand 11, CH-2009 Neuchâtel, ...

The specific capacitance of a highly porous, nitrogen-doped carbon is nearly tripled by orthogonal optimization of the microstructure and surface chemistry. First, the carbons' hierarchical pore structure and specific surface area were tweaked by controlling the temperature and sequence of the thermal treatments. The best process (pyrolysis at 900 °C, washing, and subsequent annealing at 1000 °...

Coaxial PANI/TiN/PANI nanotube arrays prepared by electrochemical polymerization of PANI on nanoporous TiN nanotube arrays exhibit a high specific capacitance of 242 mF cm(-2), excellent rate capability with the capacitance remaining at 69% when the current density is increased 50 times from 0.2 to 10 mA cm(-2), and a long cycling life with less than 0.005% decay per cycle.