Piggy bank for electricity

Supercapacitors in a car have become a reality.

Anatoly KARPENKOV, Alexander BUDKIN

Some five to ten years ago, capacitors with a capacity of one or two farads were shown at exhibitions. A little later they became available to car music lovers who wished to have an ultra-powerful Hi-Fi audio system in the car. And so, Russian industry, having overtaken both West and East for several years, mastered the small-scale production of new SUPERcapacitors. Their capacity is now measured in tens of thousands of farads.

AGILITY OF HANDS AND NO DECEPTION. The capacitor, as you know, specializes in the separation of charges: positive on one electrode ("plate"), negative - on the other.

Without going into details, we recall that the energy that a capacitor is able to “absorb” depends on the area of ​​the electrodes and the distance between them. The larger the area and the shorter the distance, the better. Therefore, increasing one and decreasing the other, we will achieve success for sure. How to do it? In the new supercapacitors, a “porous” carbon material is used to make the negative electrode, due to which a “second dimension” appears on a flat plate. As a result, the area of ​​charge accumulation increases by an order of magnitude (!).

Now about the distance. One of the names of new products is electric double layer capacitors. In them, energy accumulates in a special region - at the interface between a solid and an electrolyte. Therefore, the distance between the region of location of positive and negative charges is reduced by two to three orders of magnitude (!).

Yes, perhaps it’s time for these products to take their place under the hood of the car. What quality? There are options.

WE ARE Riding, Riding, Riding. The use of a capacitor as the main source of energy for an engine has not even been discussed recently. But the optimists once again won. The bus shown in the photo (more precisely, the electric bus) “Luzhok” uses the energy of traction capacitors made in small series in Troitsk near Moscow at the Esma plant for movement. True, for heating the cabin in severe frosts it is required to include a gasoline “stove”, but this does not count.

The machine is designed for transportation of parks or reserves inquisitive in the territory with strict environmental restrictions on closed routes. Nearing the end of the test at the All-Russian Exhibition Center in Moscow. There, the electric bus will have to make the first commercial flights. One charge of capacitors lasts about 8 km. Then a 10-15 minute charge - and again on the road. In addition to buses, a small fleet of electric vehicles with traction-type capacitors boasts a Gazelle, several electric cars and forklifts. The fundamental difference between all this "electron-accumulating" equipment from the battery technology is a longer service life of the elements and the ability to use the machines "around the clock". Charging them takes not a few hours, but a matter of minutes (although the discharge is also true).

THREE, TWO, ONE … START. It is easy to guess that the use of supercapacitors in a car as brute, albeit an electric force is a useful thing, but not the most urgent one. It is much more interesting to use their capabilities to solve short-term tasks, first of all, starting the engine. Military engineers have been thinking about this use of capacitors on army equipment for a long time. Performance tests are in full swing and are close to completion. For clarity, we give only one example. Two rechargeable batteries of 190 A.h at –45 ° C are capable of providing only one 15-second attempt to start the “740th” KamAZ-5320 engine. With a parallel connection to the battery of a capacitor with a stored energy of 50 kJ and a capacity of only 0.18 kF, the machine easily repeats several such scrolls.

The low-temperature (up to -50 ° С) launch capabilities, which are so necessary for the military or residents of the Far North, will be secondary for most motorists. The main thing will be different. Capacitors are not afraid of a high current density, they withstand a huge number of charge-discharge cycles and do not require maintenance. A “lonely” battery is considered unsuitable when it does not cope well with starting loads, but when paired with a fellow capacitor, it will serve as long as it is capable of recharging it. The battery life itself thus doubles. The required battery capacity, its weight and size are reduced in the same amount. A car will have enough 25, a truck - 60 In the future, a starter rated for high currents should be replaced by a medium discharge battery, which has an additional 2-3 times longer service life. It turns out that a combined “power plant” - a rechargeable battery plus a capacitor - may be enough for the entire life of the car (of course, you remember the best starting properties). A revolution in the automotive industry?

SOLUTIONS … TO LIFE. What is needed to make a dream come true? A little money for the development of mass production to make products more affordable, a little advertising of the advantages of the product and a little desire (if possible - disinterested) from two or three high-ranking officials. Here - as always. While capacitors are produced in small batches, they cost 2-3 times more expensive than the battery. Abroad, we are buying them a little, but do not want to seriously support Russian industry. His - it seems a little expensive. We will consider a feasible contribution to the demonstration of the benefits we have made. As for the disinterested officials … However, wait and see.

Capacitor family Esma CJSC (Troitsk).

Small: capacity - 0.36 kF, energy - 25 kJ, weight - 3.9 kg; average: 1.37 kF, 100 kJ, 16 kg; large: 3.8 kF, 270 kJ, 33 kg. All have a voltage of 12 V.

Tests at the All-Russian Exhibition Center. Circle after circle, day after day.