A newly introduced battery called the BV100 by Chinese Betavolt Technology promises to provide half a century of power, at 100 μW in a 15x15x5 mm package. Inside the package are multiple, 2 micron-thick layers nickel-63 isotope placed between 10 micron-thick diamond semiconductor, with each diamond layer using the principle of betavoltaics to induce an electrical current in a similar fashion to a solar panel using light. Ni-63 is a β emitter with a half-life of 100 years, that decays into copper-63 (Cu-63), one of the two stable forms of copper.
From the battery’s product page we can glean a bit more information, such as that the minimum size of the betavoltaic battery is 3x3x0.03 mm with one layer of Ni-63 and two semiconductor layers, allowing for any number of layers to be stacked to increase the power output within a given package. Also noted is that the energy conversion rate of the β energetic event is about 8.8%, which could conceivably be improved in the future.
Although this battery may seem new, it’s actually based on a number of years of research in diamond semiconductors in betavoltaics, with V. S. Bormashov and colleagues in 2018 reporting on a similar diamond semiconductor with Ni-63 isotope layer battery. They noted a battery specific energy of 3300 mWh/g. Related research by Benjian Liu and colleagues in 2018 showed an alphavoltaic battery, also using diamond semiconductor, which shows another possible avenue of development, since alpha particles are significantly more energetic.
Whether we’ll see Betavolt’s BV100 or similar products appear in commercial products is still uncertain, but they plan to have a 1 Watt version ready by 2025, which when packaged into the size of an average Li-ion battery pack could mean a mobile power source that will power more than a pacemaker, and cost less than the nuclear batteries powering the two Voyager spacecraft and all active Mars rovers today.
Vehicle battery recycling is going to be a big deal with all the electric cars hitting the roads. What if you could do it more effectively with the power of microbes? (via Electrek)
“Li-ion” vehicle batteries can be any of a number of different chemistries, with more complex cathode makeups, like NCM (LiNixMnyCo1-x-yO2), being understandably more complex to separate into their original constituents. Researchers and companies in the industry are hoping to find economically-viable ways to get these metals back for both the environmental and economic benefits a closed loop system could provide.
Researchers in the UK developed a method using two species of bacteria to precipitate Ni, Mn, and Co from the liquid leached from cathodes. Li remained in the liquid where it could be processed separately like that obtained in Li brine. Mn was precipitated first by S. oneidensis MR-1, and a following step removed Ni and Co with D. alaskensis G20. The researchers report that Ni and Co show promise for further separation via biological methods, but more research is required for this step.
We’re willing to bet most Hackaday readers have accidentally spot welded a few electrical contacts together over the years, complete with the surge of adrenaline that comes with the unexpected pops and sparks. It’s a mistake you’ll usually only make once or twice. But where most of us would look back at such mishaps as cautionary experiences, [Styropyro] sees an opportunity.
Armed with 100 car batteries wired in parallel, his recent video sees him pitting an assortment of household objects against the combined might of eighty-five thousand amps. Threaded rods, bolts, and angle iron all produce the sort of lightshow you’d expect, but [Styropyro] quickly discovered that holding larger objects down was more difficult than anticipated. It turns out that the magnetic fields being generated by the incredible amount of current rushing through the system was pulling the terminals apart and breaking the connection. After reinforcing the business end of his rig, he was able to tackle stouter objects such as crowbars and wrenches with explosive results.
We found that his remotely operated switch, built out of a hydraulic log splitter, to be a particular highlight of the video — unfortunately he only briefly goes over its construction at the very start. His side experiment, fashioning an sort of manually-operated carbon arc lamp with a pair of thick graphite electrodes and demonstrating is luminous efficacy compared to modern LEDs was an unexpected treat. As was the off-the-shelf domestic circuit breaker that impressed [Styropyro] by refusing to yield even after repeated jolts.
A disturbing trend in consumer electronics has been a steady disappearance of replaceable batteries on our devices. Finding a mobile phone with a swapable battery is a struggle, and many other devices follow the trend by sealing in a Li-Po cell. The result is an ever-shorter life for electronics, and a greater problem with devices going to recycling or worse still, landfill. Hope is at hand though, thanks to a proposed European Union law that would if passed make batteries in appliances “designed so that consumers can easily remove and replace them themselves“.
In case any readers in the rest of the world wonder what it has to do with them, the EU represents such a huge market that manufacturers can neither ignore it, nor in most cases afford to make separate EU and rest-of-world versions of their products. Thus if the EU requires something for sale in its territories, in most cases it becomes the de facto norm for anything designed to be sold worldwide. We’ve already seen this with the EU’s right to repair legislation, and while we have not doubt that manufacturers will do their best to impede this new law we don’t think they will ultimately prevail.
By now, we’ve gone through LiIon handling basics and mechanics. When it comes to designing your circuit around a LiIon battery, I believe you could benefit from a cookbook with direct suggestions, too. Here, I’d like to give you a collection of LiIon recipes that worked well for me over the years.
I will be talking about single-series (1sXp) cell configurations, for a simple reason – multiple-series configurations are not something I consider myself as having worked extensively with. The single-series configurations alone will result in a fairly extensive writeup, but for those savvy in LiIon handling, I invite you to share your tips, tricks and observations in the comment section – last time, we had a fair few interesting points brought up!
The Friendly Neighborhood Charger
There’s a whole bunch of ways to charge the cells you’ve just added to your device – a wide variety of charger ICs and other solutions are at your disposal. I’d like to focus on one specific module that I believe it’s important you know more about.
You likely have seen the blue TP4056 boards around – they’re cheap and you’re one Aliexpress order away from owning a bunch, with a dozen boards going for only a few bucks. The TP4056 is a LiIon charger IC able to top up your cells at rate of up to 1 A. Many TP4056 boards have a protection circuit built in, which means that such a board can protect your LiIon cell from the external world, too. This board itself can be treated as a module; for over half a decade now, the PCB footprint has stayed the same, to the point where you can add a TP4056 board footprint onto your own PCBs if you need LiIon charging and protection. I do that a lot – it’s way easier, and even cheaper, than soldering the TP4056 and all its support components. Here’s a KiCad footprint if you’d like to do that too.
Most of the batteries we use these days, whether rechargeable or not, are generally self-contained affairs. They come in a sealed package, with the anode, cathode, and electrolyte all wrapped up inside a stout plastic or metal casing. All the reactive chemicals stay inside.
However, a certain class of magnesium batteries are manufactured in a dry, unreactive state. To switch these batteries on, all you need to do is add water! Let’s take a look at these useful devices, and explore some of their applications.
In the first article, I’ve given you an overview of Lithium-Ion batteries and cells as building blocks for our projects, and described how hackers should treat their Lithium-Ion cells. But what if you don’t have any LiIon cells yet? Where do you get LiIon cells for your project?
Taking laptop batteries apart, whether the regular 18650 or the modern pouch cell-based ones, remains a good avenue – many hackers take this road and the topic is extensively covered by a number of people. However, a 18650 cell might not fit your project size-wise, and thin batteries haven’t quite flooded the market yet. Let’s see what your options are beyond laptops. Continue reading “Lithium-Ion Batteries Are Easy To Find”→