Carbon Composite for Vanadium Batteries

2022: Representation of Carbon Composite Material

Russian scientists have synthesized a carbon composite material to create vanadium batteries designed to efficiently store large amounts of energy. Bipolar plates made of such a material are corrosion resistant, easy to manufacture and use, and can significantly reduce the cost of "green" electricity for the end user. This was reported to TAdviser by representatives of NUST MISIS on August 3, 2022.

Since renewable power is significantly dependent on the weather and time of day, its breakthrough development requires powerful and affordable energy storage systems. As of 2022, the vanadium flow battery is the most promising type of rechargeable chemical current source for creating large and medium-scale power storage devices necessary to solve the problems of modern power.

As explained in NUST "MISIS," a flowing battery is an electric energy storage device, which is a cross between a conventional battery and a fuel cell. In them, liquid electrolyte is pumped through the core using pumps. The main component of such a battery is a metal bipolar plate, in which energy is converted into electricity. As a rule, they are made of graphite, which has excellent electrical conductivity and chemical stability, but its disadvantages include significant permeability to electrolytes, which reduces efficiency and reduces battery life, as well as a complex processing process for feedstocks.

A group of scientists from their MISIS University,, Institute of Problems of Chemical Physics RAS Skoltech RKHTU named after D.I. Mendeleev together with the company's specialists InEnergy proposed using a carbonized elastomeric composite highly filled with conductive carbon fillers as a material for the manufacture of bipolar plates instead of fine-grained isotropic graphite. Such a material has high chemical resistance and makes it possible to adjust the electrical and mechanical properties of the plate made from it.

Bipolar plates were made using carbon fibers of the Toray T700 brand, crushed artificial graphite, and carbon black of the N220 brand. The final formation of the properties was carried out by heating in an inert medium to a temperature of 340 degrees Celsius.

The total volume fraction of carbon fillers in the obtained samples was 75% of the total weight. Including the share of carbon fibers up to 12.25 percent. With an increase in the degree of filling with carbon fibers, the mechanical properties of the resulting composite material increase, told in NUST "MISIS."

"The developed material can be an excellent replacement for the used imported carbon-composite materials of bipolar plates of flow batteries. However, first you need to wait for the results of resource tests in real devices to confirm the long-term stability of the material, "said the author of the work, an expert at the Center for Energy Efficiency of the University" MISIS "Ph.D.

The composite synthesized by Russian scientists has a homogeneous structure, has resistance to electrolytes and electrical conductivity sufficient for its use in industrial high-power vanadium flow batteries. At the same time, the properties of the material make it possible to use it for the serial production of bipolar plates with a complex architecture.

The work was carried out with the support of a grant from the Russian Science Foundation N- 19-79-00334. The study of Russian scientists was published in the journal Materials today Communications.