In theory, you can make a battery based on decay by using more magnetic core materials according to the time needed. But the question is how long the device needs to rest, and before the electrons deteriorate or fall apart, the electrons How it will continue to operate in the application has nothing to do with the radioactive decay mechanism itself.

　　The correct choice of long-life battery, even in a very low discharge state, is more important than the analysis of the basic current-and-time battery capacity.

　　The growing interest in long-lived embedded applications is just like the endless engineering questions that remote data logging or electricity meters bring: How do we drive or charge these devices? These devices, which usually work in harsh environments, need to work for 10, 20, or even more years under a small battery-powered state that is not often noticed.

　　For devices that only require a few years of continuous operation and a short life cycle, the battery decision analysis starts from the basic analysis of the current consumption, such as the various duty cycles of the battery, and the comparison between the operating mode and the battery capacity (mA/hour) In this way, you can get quite complex and complex applications and operating cycles, but it is not too difficult, at least you can set an upper limit in the worst case. However, when the equipment needs to operate for 10 years or longer, the basic electronic analysis of the load current and the power capacity are only small influencing factors, such as self-discharge, chemical deterioration and shell corrosion will become major problems.

　　When I read the article "Designing and Fabricating a Multiple-Decade Battery" published in Aerospace & Defense Technology (Aerospace & Defense Technology), the reason why I was curious about battery life. This article describes in detail a thermoelectric generator (TEG) based on radioactive decay, which can theoretically run for 150 years. The architecture uses a two-step process that I have never seen before. One is to generate light for decay; the next is to use Solar cells generate electricity. The author hints that this method is inefficient in the article. Unfortunately, the exact conversion efficiency figures are not listed in the article, but I suspect it is within the range of less than 5%.　　 The thermoelectric generator has been successfully used for more than 10 years by charging through radioactive decay, especially the spacecraft with the smallest solar radiation. These thermoelectric generators use a single-stage conversion process based on radioactive decay heat energy, rather than two-step process (Two-step Process) photons, and the Seebeck-junction thermocouple to generate electricity from the attenuation heat.

　　This method provides power for Voyager 1 and 2 issued in 1977. The two spacecraft are still traveling in space and continue to transmit data back to Earth, even though they have crossed the fuzzy boundary of the solar system into another outer space (Exospace). ). (Editor's note: The source of the spacecraft mentioned by the author of this article is Voyager: Seekingnewerworldsinthethirdgreatageofdiscovery written by StephenJ.Pyne~) There are some work on using thermocouples to capture waste heat from the engine, but how do these studies become reality? (Cost, reliability, size and efficiency) is still unclear.

　　certainly! In theory, you can make a battery based on decay by using more magnetic core materials according to the time needed. But the question is how long the device needs to rest, and before the electrons deteriorate or fall apart, the electrons How it will continue to operate in the application has nothing to do with the radioactive decay mechanism itself. But if the battery does not meet the needs of the past 100 years, no one will be around today to criticize these tasks.

　　I also read two other articles about long-life batteries, one of which is choosing the right battery for high-tech batteries (ChoosingtheRightBatteriesforHigh-TechBatteries), which comes from the NASATechBriefs (NASATechBriefs), which focuses on various chemical substances. The properties of, especially the many interesting variants of the lithium battery family, this article puts it in one sentence: very complicated. When you need to use the battery for more than 10 years, even under very low current or low rate pulse cycle, you will need to analyze many factors, such as self-discharge and temperature rating. In addition, mA-Hr capacity has become one of many parameters to consider. one.

　　Although the author of the above article comes from a well-known battery manufacturer (Tadiran), and may have some deviations in opinions, I would rather listen to the research records of some people who have actually developed products in this field, and the delicate manufacturing and production of products Problem, not just an academic expert. (Editor’s note: The author’s vernacular is that... he doesn’t trust the arguments of the experts on the paper...) The same battery supplier also has a small article "Power Your Wireless Sensors for 40 Years", This short article overlaps with the article mentioned earlier, but it also adds some new information.

　　Are you involved in deciding the choice of long-life battery? How do you evaluate the basic power capacity required by the battery in a complex operating cycle? How do you decide the shape and chemistry of the long-life battery will be feasible?