About “super-long” atomic battery with 10 times increased power
This is a story about an innovative autonomous power source – a compact atomic battery that can last up to 20 years. Due to the original 3D-structure of the beta-voltaic element, its dimensions have decreased threefold, the specific power has increased by an order of magnitude, and the cost price has decreased by 50%. Yes, this is such a miracle of technology. Russian is austere and original.
Scientists from NUST MISIS under the leadership of Professor of the Department of Semiconductor Electronics and Semiconductor Physics Viktor Murashov presented an innovative autonomous power source – a compact atomic battery that can last for decades. Due to the original 3D-structure of the beta-voltaic element, its dimensions have decreased threefold, the specific power has increased 10 times, and the cost price has decreased by 50%. The results are published in an international scientific journal Applied Radiation and Isotopes.
The device uses the original, patented microchannel 3D structure of a nickel betavoltaic cell… Its peculiarity is that a radioactive element is applied on both sides of a planar pn junction, which makes it possible to simplify the cell manufacturing technology, as well as to control the reverse current, which “steals” the battery power. The special microchannel structure provides an increase in the effective conversion area of beta radiation by 14 times, which results in an overall increase in current.
“The output electrical parameters of the proposed design were: short-circuit current IKZ – 230 nA / cm2 (in the usual planar – 24 nA), the final power – 31nW / cm2, (in the planar – 3nW). The design makes it possible to increase by an order of magnitude the efficiency of converting the energy released during the decay of a β-source into electricity, which in the future will reduce the cost of the source by about 50% due to the rational use of an expensive radioisotope, – says one of the developers Sergey Legotin, associate professor of the Department of Semiconductor Electronics and Semiconductor Physics, NUST MISIS.
The optimal parameters of the converter design are determined and its main characteristics are calculated. Based on the calculations performed, it can be concluded that the 3D structure will increase the active surface area by a factor of 14 (at a microchannel depth of 80 μm), as well as the probability of beta particles penetrating into the pn junction in comparison with the planar structure of the converter. And, as a consequence, the density of nonequilibrium charge carriers and the output power of the device increase. The output electrical parameters of the proposed design with a specific activity of Ni-63 of 2.7 mCi were:
short-circuit current IKZ = 276 μA / cm2 (in planar – 24 nA);
no-load voltage UXX = 149 mV (125 mV for planar);
power P = 23.7 μW / cm2;
Efficiency: η = 1.4%. 3D beta-voltaic element with two-way transformation., – explains Sergey Legotin.
At the same time, the development will make it possible to increase the specific power by an order of magnitude, due to which the weight and size indicators of the batteries based on them will decrease three times while maintaining the required output power level.
The battery can be used in several functional modes: as an emergency power supply and temperature sensor in devices used at extreme temperatures and in hard-to-reach (or completely inaccessible) places: in space, under water, in high-altitude areas.
The unique properties of the power supply are record-high specific energy consumption, reliability, the ability to operate without maintenance and an unprecedented long service life. Betavoltaic converters will become indispensable in situations where chemical batteries cannot provide long-term and stable operation, for example, in tasks related to space exploration or power supply of devices at critically low temperatures – in the Arctic and Polar regions.
At the moment, the developers are completing the procedure for international patenting of the invention, and the device itself has already been recognized by foreign experts. In particular, in aboutoverview of the international marketing research agency Research and Markets NUST MISIS was named one of the key players in the global betavoltaic batteries market. The university ranks among such companies as City Labs, BetaBatt, Qynergy Corp and Widetronix.
The review indicates that the development of NUST MISIS scientists – a battery based on beta-voltaic cells (BVE) – has great potential, since the demand for reliable batteries with a long service life is growing in all industries. Taking into account the unique characteristics – small size and safety – the development of NUST MISIS will be able to occupy a significant share of the power supply market.