Metal‐Carbon Composite Electrodes from Fiber Precursors: II . Electrochemical Characterization of Stainless Steel‐Carbon Structures

Abstract

In this study, the capacitances of stainless steel-carbon composite electrodes in 1.0M Na2SO4 were determined as a function of stainless steel loading, sintering temperature, and sintering time (i.e., O. 1-0.5g of stainless steel fiber/lg of carbon fiber, 1323-1423 K, and 2.5-152 min, respectively). Kinetic parameters were determined for stainless steel sintering and catalytic carbon gasification by weight loss measurements and capacitance changes using ac impedance, single potential step methods, and cyclic voltammetry. Apparent activation energies for carbon gasification and sintering were found to be 80 and 200 kJ/mol, respectively. Measured reaction rates and kinetic parameters were used to verify the importance of stainless steel-carbon contacts toward overall electrode capacitance and to successfully predict a maximum capacitance of 45.3 F/g on a total electrode weight basis. This capacitance value yields energy densities of ca. 90 kJ/kg of electrode and does not require pressure for good electrical contact as do electrodes prepared from carbon powders. Capacitance and kinetic measurements demonstrate the ability to control conductivity and active surface area by adjusting: stainless steel to carbon loading, sintering temperature, and sintering time.

Electrochemical and Integrated Process Opportunities for On-Site/On-Demand Generation of Chlorine Dioxide - Final Report - 08/02/1996 - 08/01/1999

“…demonstrated that high performance, three dimensional, microfibrous electrodes can improve the performance of capacitors, batteries, hybrid power cells, and electrolysis electrodes in a variety of applications [2,3]. The goal of this research was to apply this technology to a chlorate cell's cathode and reduce the overpotential between 200 and 400…”

“…The catholyte in chlor-alkali cells is 30 wt% NaOH, which is non-corrosive towards both nickel and stainless steel. Previous research projects have provided the Auburn University Center for Microfibrous Materials Manufacturing with considerable expertise in designing nickel microfibrous materials [2,3]. As a result, the catalytic activity of a composite microfibrous material towards hydrogen evolution was tested in a chlor-alkali cell before a chlorate cell.…”

Sol−Gel Synthesis and Characterization of Carbon/Ceramic Composite Electrodes

“…For example, carbon particles can be combined with an organic polymer binder such as poly(vinylidene difluoride) (PVDF), poly(tetrafluoroethylene) (PTFE), or ethylene/propylene/diene polymer (EPDM) forming a conductive, porous composite electrode. [5][6][7] Carbon particles can also be embedded into a metallic support such as stainless steel, 8 and carbon aerogels have been used to fabricate high surface area electrodes. 9 The carbon particles used for these applications are typically about 1-10 µm in diameter and have a wide range of crystal structures and morphologies.…”

“…Carbon electrodes are widely used in electrochemical charge storage, energy generation, and catalysis. − Various techniques have been developed for the synthesis of these electrodes. For example, carbon particles can be combined with an organic polymer binder such as poly(vinylidene difluoride) (PVDF), poly(tetrafluoroethylene) (PTFE), or ethylene/propylene/diene polymer (EPDM) forming a conductive, porous composite electrode. − Carbon particles can also be embedded into a metallic support such as stainless steel, and carbon aerogels have been used to fabricate high surface area electrodes ,,− Both low surface area graphite particles and high surface area carbons are used for the anode in lithium ion batteries .…”

Electrochemical Reduction of Oxygen at “Electrocoated” Nafion‐Modified Metal‐Carbon Composite and Platinum Electrodes

“…Tatarchuk et al 13,14 recently have reported the development and preliminary characterization of a stainless steelcarbon composite electrode which combines the high surface area of activated carbon fibers with the high conductivity of stainless steel fibers into a self-supporting sintered network. The electrodes are highly permeable to liquids and gases and have excellent electrical conductivity.…”