Recycling of residues as precursors of carbons for supercapacitors

En: 1st Spanish National Conference on Advances in Materials Recycling and Eco – Energy Madrid, 12-13 November 2009.-- Editors: F. A. López, F. Puertas, F. J. Alguacil and A. Guerrero.-- 4 pages, 3 figures, 1 table.It is shown that industrial wastes such as apple pulp (generated in the cider production), cherry stones (from the industrial manufacture of Kirsh and jam) and PET (plastic vessels) can be recycled as activated carbons for electrode material in supercapacitors. These precursors allow obtaining carbons with large specific surface areas (up to 1200 m2g-1) and average pore sizes around 0.9-1.3 nm, which makes them accessible to electrolyte ions. These features lead to electrical capacitances at low current density as high as 230 F g-1 in 2M H2SO4 aqueous electrolyte and 120 F g-1 in the aprotic medium 1M (C2H5)4NBF4 / acetonitrile. Furthermore, high performance is also achieved at high current densities, which means that the activated carbons derived from residues compete well with commercial carbons used at present in supercapacitors.Peer reviewe

Correlation between capacitances of porous carbons in acidic and aprotic EDLC electrolytes

5 pages, 4 figures, 2 tables.-- Printed version published Jun 2007.A study based on a total of 41 nanoporous carbons shows that there exists a good correlation between the limiting gravimetric capacitances Co at low current densities j (1 mA cm−2) measured in aprotic (1 M (C2H5)4 NBF4 in acetonitrile) and in acidic (2 M aqueous H2SO4) electrolytes. The comparison of the surface-related capacitances (F m−2) of well characterized samples with the amount of thermodesorbed CO suggests a strong contribution of CO generating surface groups to charge storage in the acidic electrolyte, but a negligible contribution in the aprotic medium. It also appears that the decrease of the capacitance with current density is similar in both electrolytes. This confirms that the average micropore width and the CO2 generating surface groups are the main factors which limit the ionic mobility in both electrolytes.Peer reviewe

The ALPS project: open source software for strongly correlated systems

We present the ALPS (Algorithms and Libraries for Physics Simulations) project, an international open source software project to develop libraries and application programs for the simulation of strongly correlated quantum lattice models such as quantum magnets, lattice bosons, and strongly correlated fermion systems. Development is centered on common XML and binary data formats, on libraries to simplify and speed up code development, and on full-featured simulation programs. The programs enable non-experts to start carrying out numerical simulations by providing basic implementations of the important algorithms for quantum lattice models: classical and quantum Monte Carlo (QMC) using non-local updates, extended ensemble simulations, exact and full diagonalization (ED), as well as the density matrix renormalization group (DMRG). The software is available from our web server at http://alps.comp-phys.org.Comment: For full software and introductory turorials see http://alps.comp-phys.or