RVC as new carbon material for batteries

Abstract

Results of the last 10 years of our investigations on the use of reticulated vitreous carbon (RVC Ò ) in various types of cells show that this kind of porous conductive glassy carbon can be successfully used as a matrix for active mass and as a current collector in many primary and secondary batteries. This paper focuses mainly on the use of RVC Ò modified with metals like Pt, Rh, Pd, Ni, Pb and their oxides in construction of the following types of cells: (1) zinc-carbon primary and secondary batteries, (2) rechargeable cell systems with NiOOH cathode, (3) electrochemical capacitors with Pd and Pd-Rh alloys, and (4) lead acid battery. The most important improvement in performance has been achieved with lead-acid and zinccarbon batteries. Especially for the modified zinc-carbon battery, which has been constructed in the popular AA format, manufactured on a small (laboratory) scale, and tested according to the IEC norms as a battery for commercial use, the capacity has been higher by ca. 20% compared with the batteries available on the market. Also, results obtained for thin layers of Pd and their alloys deposited on RVC Ò are promising in terms of the application of these kinds of electrodes in electrochemical capacitors. The pseudocapacitance of a Pd-Rh/RVC Ò composition may reach 540 F g -1 .

Characteristic of hydrogen-saturated Pd-based alloys for the application in electrochemical capacitors

“…The experimental values found in our studies [11][12][13] were in the range 240-430 Fg −1 for Pd and up to 540 Fg −1 for Pd-Rh alloys (97% Pd in the bulk). This tendency is consistent with the data presented in Fig.…”

“…These curves are typical of hydrogen extraction form thin Pdbased layers and were described in detail in earlier reports [12][13][14][15][16][17]. By the integration of hydrogen oxidation currents the amount of absorbed hydrogen was obtained.…”

“…The details of the preparation of thin Pd-based deposits on Au substrate are given in other reports [8][9][10]. For comparison, the characteristic of Pd and Pd-Rh deposits (thickness in the range 0.6-1.0 μm) on RVC with the porosity grade of 20 pores per inch (ppi) is presented on the basis of our previous studies (see [11][12][13] for more information).…”

“…In earlier papers [12,13], we reported Fig. 4 Influence of temperature and alloy composition on: a average specific power, b maximum specific power (per mass of electroactive material) for hydrogen desorption process on the electrochemical behavior of Pd and Pd-Rh (92-97% Pd in the bulk) layers deposited on RVC.…”

The continued development of reticulated vitreous carbon as a versatile electrode material: Structure, properties and applications

“…RVC has been demonstrated to increase charge capacity per unit area, energy and power density as well as being a versatile material for metal coating, electro-polymerisation and modification with nanoparticles for use as battery current collectors. Previously, a short review of RVC as a battery electrode was published [27], which considered the possibilities of using RVC to overcome the limitations of various types of batteries, such as zinc-carbon, NiOOH, lead acid as well as in Pd-based capacitors. The high surface area of RVC, in combination with catalyst modification, could lead to improvement of the energy density of common batteries.…”