Fluoropolymer impregnated graphite foil as a bipolar plates of vanadium flow battery

Abstract

Summary Renewable energy in recent years plays an increasingly important role in the energy industry. Therefore, the problem of inventing efficient and affordable energy storage devices is of current importance. Vanadium redox flow battery stands out between a wide range of various chemical sources of electric energy. Discovering the way for optimizing the price of energy storage is one of the most important questions of the mentioned battery. New graphite‐polymer composite materials study shows that they may become a replacement for commonly used brittle graphite. The current article presents the study of graphite foil (or flexible graphite) filling with a copolymer of tetrafluoroethylene and vinylidene fluoride F‐42 properties. The article uses an implementation approach of putting the fluoropolymer into the pores of graphite foil, which shows a slight decrease in electrical conductivity, while a significant increase in its electrochemical stability in comparison with untreated graphite foil. Testing results of such material as current collectors (or bipolar plates) in a single membrane‐electrode assembly of vanadium redox flow battery cell show peak value of discharge power density of 843 mW/cm2, energy efficiency of 78%‐79% during cycling at 200 mA/cm2 allowing us to assume the possibility of its successful application in redox flow battery stacks.

Mixture of Anthraquinone Sulfo-Derivatives as an Inexpensive Organic Flow Battery Negolyte: Optimization of Battery Cell

“…As one of the thinnest membranes it was selected to estimate the limits of ABRFBs power density. GP-IEM-103 is an inexpensive perfluorosulfonic proton-exchange membrane with conductivity 0.1 S/cm and density 2 g/cm 3 , which can be also used in RFB [ 63 ]. The key difference between them is thickness, for Nafion 211 it is 25 µm, and for GP-IEM-103—75 µm.…”

Promising Material Based on Paraffin‐Impregnated Graphite Foil with Increased Electrochemical Stability for Bipolar Plates of Vanadium Redox Flow Battery

“…It was shown that assemblies on GF can be successfully used as BP on the development stage of RFB. [31] In order to demonstrate the possibility of successful application of the developed material for long-term use in real RFBs, we performed longterm charge-discharge tests of individual MEA of VRFB with the obtained GF samples (see Figure 8). Since the degradation of the GF with open porosity under polarization at potentials ChemistrySelect beside potential window occur within ten minutes, the overall duration of the cycling tests was 50 cycles that exceed the time of GF destruction about 300 times.…”

“…In our previous work, the method of filling GF pores with the copolymer of tetrafluoroethylene and vinylidene fluoride (F-42) was demonstrated. [31] The choice was determined by F-42 excellent chemical stability and unique solubility in ketones and esters. It was shown that impregnation of GF with F-42 allows increasing electrochemical stability along with keeping high electrical conductivity of GF.…”

Fabrication of Bipolar Plates from Thermoplastic Elastomer Composites for Vanadium Redox Flow Battery

“…A pressure drop in cells influences the energy efficiency of flow batteries [ 5 , 6 , 7 ], while electrolyte distribution uniformity affects concentration loss [ 6 , 8 ] and voltage efficiency [ 5 ]. In order to provide electron pathways, bipolar plates must, also, have a high electrical conductivity [ 9 ]. The ohmic loss and voltage efficiency of flow batteries are affected by surface and volume electrical conductivity [ 10 ].…”