It’s another one of those fun quirks about our increasingly cyberpunk world — instead of cigarette butts littering our streets, you’re more likely to find disposable vaporizers that have run out of juice. Unfortunately, while the relatively harmless paper remnants of a cig would eventually just fall apart when exposed to the elements, these futuristic caltrops are not only potentially explosive thanks to their internal lithium-ion battery but aren’t going anywhere without some human intervention.
So do the environment and your parts bin a favor: pick them up and salvage their internal cells. As [N-Ender_3] shows with this build, it’s cheap and easy to turn the remnants of a few vapes into a useful USB power bank. In this case, the enclosure is 3D printed, which makes it particularly form-fitting, but you could just as easily pack the cells into something else if you’re not a fan of extruded plastic.
Many readers will have at some time or another built their own lithium-ion battery packs, whether they are using tiny cells or the huge ones found in automotive packs. A popular choice it to salvage ubiquitous 18650 cylindrical cells, as [limpkin] has with this 48 volt pack. It’s based around an off-the-shelf kit aimed at the e-bike market, but it’s much more than a simple assembly job.
Faced with a hundred salvaged cells of unknown provenance, the first thing to do was ensure that they were all balanced and showed the same voltage. Some might do this the inefficient way by hooking each one up to a charger and a programmable load, but in this case a much more radical route was taken. A huge PCB was designed with sockets for all hundred cells, connected in parallel through individual series resistors. This allowed them to balance to a common voltage before being discharged to a safe voltage for assembly. Their individual ESRs were the measured, and the best performing examples were then spot-welded into the final 13s-6p final pack.
The process of creating new battery chemistries that work better than existing types is a slow and arduous one. Not only does it know more failures than successes, it’s rare that a once successful type gets completely phased out, which is why today we’re using lead-acid, NiMH, alkaline, lithium, zinc-air, lithium-ion and a host of other battery types alongside each other. For one of the up-and-coming types in the form of sodium (Na)-based batteries the same struggles are true as it attempts to hit the right balance between anode, cathode and electrolyte properties. A pragmatic solution here involves Prussian Blue for the cathode and hard carbon for the anode, as is the case with Swedish Northvolt’s newly announced sodium-ion battery (SIB) which is sampling next year.
Commercialization of different SIB battery chemistries by various companies. (Credit: Yadav et al., 2022)
The story of SIBs goes back well over a decade, with a recent review article by Poonam Yadav and colleagues in Oxford Open Materials Science providing a good overview of the many types of anodes, cathodes and electrolytes which have been attempted and the results. One of the issues that prevents an SIB from directly using the carbon-based anodes employed with today’s lithium-ion batteries (LIB) is its much larger ionic radius that prevents intercalation without altering the carbon material to accept Na+ ions.
This is essentially where the hard carbon (HC) anode used by a number of SIB-producing companies comes into play, which has a far looser structure that does accept these ions and thus can be used with SIBs. The remaining challenges lie then with the electrolyte – which is where an organic form is the most successful – and the material for the sodium-containing cathode.
Although oxide forms and even sodium vanadium fluorophosphate (NVPF) are also being used, Prussian Blue analogs (PBAs) are attractive for being very low-cost and effective as cathode material once processed. An efficient way to process PB into fully sodiated and reduced Prussian White was demonstrated a few years ago, followed by successive studies backing up this assessment.
Although SIBs are seeing limited commercial use at this point, signs are that if it can be commercialized for the consumer market, it would have similar capacity as current LIBs, albeit with the potential to be cheaper, more durable and easier to recycle.
If there’s anything people hate more than being locked into a printer manufacturer’s replacement cartridges, it’s proprietary batteries. Cordless power tools are the obvious example in this space, but there are other devices that insist on crappy battery packs that are expensive to replace when they eventually die.
One such device is the Uniden Bearcat BC296D portable scanner that [Robert Guildig] found for a song at a thrift store, which he recently gave a custom LiPo battery upgrade. It came equipped with a nickel-cadmium battery pack, which even under the best of circumstances has a very limited battery life. Using regular AA batteries wasn’t an option, but luckily the space vacated by the OEM battery pack left a lot of room for mods. Those include a small module with BMS functions and a DC-DC converter, a 2,400 mAh 4.2 V LiPo pillow pack, and a new barrel connector for charging. With the BMS set for six volts and connected right to the old battery pack socket, the scanner can now run for seven hours on a one-hour charge. As a bonus, the LiPo pack should last a few times longer than the NiCd packs, and be pretty cheap to replace when it finally goes too. There’s a video after the hop with all the details.
You may have heard us here remarking in the past, that if we had a pound, dollar, or Euro for every miracle battery technology story we heard that was going to change the world, we would surely be very wealthy by now. It’s certainly been the case that many such pronouncements refer to promising chemistries that turn out only to be realizable in a lab, but here there’s news of one with a bit of pedigree. Nickel hydrogen batteries have a long history of use in space, and there’s a startup producing them now for use on the ground. Could they deliver the energy storage Holy Grail?
The cathode in a nickel-hydrogen battery is formed by nickel hydroxide, and the anode is formed of hydrogen. If a gas as an anode sounds far fetched, we’re guessing that their structure is similar to the zinc-air battery, in which zinc hydroxide forms in a paste of powdered zinc, and works against oxygen from the air over a porous conductive support. What gives them their exciting potential is their ability to take more than 30,000 charge/discharge cycles, and their relative safety when compared to lithium ion cells. Hydrogen in a pressure vessel might not seem the safest of things to have around, but the chemistry is such that as the pressure increases it reacts to form water. The cost of the whole thing is reduced further as new catalysts have replaced the platinum used by NASA on spacecraft.
We really hope that these batteries will be a success, but as always we’ll wait and see before calling it. They may well be competing by then with the next generation of zinc-air cells.
The news is rife with claims of the next great thing in clean energy generation, but most of these technologies never make it to production. Whether that’s due to cost issues, production, or scalability, we’re often teased with industry breakthroughs that never come to fruition. Multi-layered solar panels, wave and tidal energy, and hydrogen fuel cells are all things that are real but can’t seem to break through and overtake other lower cost, simpler, and proven technologies. One that seems to be bucking this trend is the liquid metal battery, which startup Ambri is putting into service on the electrical grid next year.
With lithium ion battery installations running around $405 per kilowatt-hour, Ambri’s battery technology is already poised to be somewhat disruptive at a cost of about half that. The construction method is simpler than lithium as well, using molten metal electrodes and a molten salt electrolyte. Not only is this more durable, it’s also not flammable and is largely immune to degradation over time. The company’s testing results indicate that after 20 years the battery is expected to still retain 95% of its capacity. The only hitch in scaling this technology could be issues with sourcing antimony, one of the metals needed for this type of construction.
Even though Ambri can produce these batteries for $180 to $250 per kilowatt-hour, they need to get the costs down to about $20 for the technology to be cost-competitive with “base load” power plants (an outdated term in itself). They do project their costs to come down significantly and hit this mark by 2030, which would put electrical grids on course to be powered entirely by renewables. Liquid metal batteries aren’t the only nontraditional battery out there trying to solve this problem, though. Another promising interesting energy storage technology on the horizon is phase-change materials.
When it comes to powering tiny devices for a long time, coin cell batteries are the battery of choice for things like keyfobs, watches, and even some IoT devices. They’re inexpensive and compact and a great choice for very small electricity needs. Their major downside is that they have a relatively high internal resistance, meaning they can’t supply a lot of current for very long without decreasing the lifespan of the battery. This new integrated circuit uses a special DC-DC converter to get over that hurdle and extend the life of a coin cell significantly.
A typical DC-DC converter uses a rapidly switching transistor to regulate the energy flow through an inductor and capacitor, effectively stepping up or stepping down the voltage. Rather than relying on a single converter, this circuit uses a two-stage system. The first is a boost converter to step the voltage from the coin cell up to as much as 11 volts to charge a storage capacitor. The second is a buck converter which steps that voltage down when there is a high current demand. This causes less overall voltage drop on the battery meaning less stress for it and a longer operating life in the device.
There are a few other features of this circuit as well, including an optimizer which watches the behavior of the circuit and learns about the power demands being placed on it. That way, the storage capacitor is only charged up to its maximum capacity if the optimizer determines that much charge is needed. With all of these features a coin cell could last around seven times as long as one using more traditional circuitry. If you really need to get every last bit of energy from a battery, though, you can always use a joule thief.
