Prototype Sodium Ion Batteries in 18650 Cells

French researchers have announced a prototype of an 18650 sodium-ion battery. If you’ve bought a powerful LED flashlight, a rechargeable battery pack, or a–ahem–stronger than usual LASER pointer, you’ve probably run into 18650 batteries. You often find these inside laptop batteries and –famously– the Tesla electric vehicle runs on a few thousand of these cells. The number might seem like a strange choice, but it maps to the cell size (18 mm in diameter and 65 mm long).

The batteries usually use lithium-ion technology. However, lithium isn’t the only possible choice for rechargeable cells. Lithium has a lot of advantages. It has a high working voltage, and it is lightweight. It does, however, have one major disadvantage: it is a relatively rare element. It is possible to make sodium-ion batteries, although there are some design tradeoffs. But sodium is much more abundant than lithium, which makes up about 0.06% of the Earth’s crust compared to sodium’s 2.6%). Better still, sea water is full of sodium chloride (which we call salt) that you can use to create sodium.

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Storing Energy in Liquid Form

Researchers in Singapore have created a new kind of redox flow battery with an energy density around ten times higher than conventional redox flow batteries. Never heard of a redox flow battery? These rechargeable batteries have more in common with fuel cells than conventional batteries. They use two circulating liquids separated by a membrane as an electrolyte. Each liquid has its own tank, and you can recharge it by pumping in fresh electrolyte. The redox in the name is short for reduction-oxidation and refers to the process that stores energy in the two liquids. You can learn more about flow batteries in the video from Harvard below.

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Tiny PIC Clock is Not a Tiny Bomb

It’s been a few weeks since the incident where Ahmed Mohamed, a student, had one of his inventions mistaken for a bomb by his school and the police, despite the device clearly being a clock. We asked for submissions of all of your clock builds to show our support for Ahmed, and the latest one is the tiniest yet but still has all of the features of a full-sized clock (none of which is explosions).

[Markus]’s tiny clock uses a PIC24 which is a small yet powerful chip. The timekeeping is done on an RTCC peripheral, and the clock’s seven segment displays are temporarily lit when the user presses a button. Since the LEDs aren’t on all the time, and the PIC only consumes a few microamps on standby, the clock can go for years on a single charge of the small lithium-ion battery in the back. There’s also a phototransistor which dims the display in the dark, and a white LED which could be used as a small flashlight in a pinch. If these features and the build technique look familiar it’s because of [Markus’] tiny MSP430 clock which he was showing around last year.

Both of his tiny clocks are quite impressive for their size, features, and power consumption. Some of the other clocks we’ve featured recently include robot clocks, clocks for social good, and clocks that are not just clocks (but still won’t explode). We’re suckers for a good clock project here, so keep sending them in!

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Hackaday Prize Semifinalist: Artificial Muscles and Supercapacitors

For [Lloyd T Cannon III]’s entry to the Hackaday Prize, he’s doing nothing less than changing the way everything moves. For the last 100 years, internal combustion engines have powered planes, trains, and automobiles, and only recently have people started looking at batteries and electric motors. With his supercapacitors and artificial muscles, [Lloyd] is a few decades ahead of everyone else.

There are two parts to [Lloyd]’s project, the first being the energy storage device. He’s building a Lithium Sulfur Silicon hybrid battery. Li-S-Si batteries have the promise to deliver up to 2000 Watt hours per kilogram of battery. For comparison, even advanced Lithium batteries top out around 2-300 Wh/kg. That’s nearly an order of magnitude difference, and while it’s a far way off from fossil fuels, it would vastly increase the range of electric vehicles and make many more technologies possible.

The other part of [Lloyd]’s project is artificial muscles. Engines aren’t terribly efficient, and electric motors are only good if you want to spin things. For robotics, muscles are needed, and [Lloyd] is building them out of fishing line. These muscles contract because of the resistive heating of a carbon fiber filament embedded in the muscle. It’s been done before, but this is the first project we’ve seen that replicates the technique in a garage lab.

Both parts of [Lloyd]’s project are worthy of a Hackaday Prize entry alone, but putting them together as one project more than meets the goal: to build something that matters.

The 2015 Hackaday Prize is sponsored by:

Better Batteries For Electronic Gadgets

We’re not using 9 Volt batteries to power our projects anymore; the world of hobby electronics has moved on to cheap LiPo batteries for most of our mobile power storage. LiPos aren’t the best solution, evidenced by hundreds of YouTube videos of exploding batteries, and more than a few puffy cells in our junk drawer. The solution? LiFePO4, or lithium iron phosphate cells. They’re a safer chemistry, they have low self discharge, and have more recharge than other chemistry of lithium cells.

LiFePO4 cells aren’t easy to deal with if you’re working with breadboard electronics, though. Most of that is because there aren’t many breakout boards for these cells. [Patrick] is working on changing that with his LiFePO4werd USB charger.

The concept is simple: use an off-the-shelf part for LiFePO4 batteries – in this case an MCP73123 – and make a board that charges the batteries with a USB port. It’s exactly the same idea as the many USB LiPo chargers out there, only this one uses a better battery chemistry.

[Patrick] is using a 550mAh battery for this project, but there’s no reason why it couldn’t be upgraded to a 18650-sized cell with more than 2000mAh stuffed inside. Add a boost converter to the circuit, and he’ll have the perfect power source for every portable electronics project imaginable.

Hackaday Prize Semifinalist: A Smart Battery Analyzer

[K.C. Lee]’s entry for the Hackaday Prize won’t cure cancer, wipe a disease from the planet, stop an alien invasion, or save the world. His battery charger and analyzer is, however, a useful little device for determining the charge and discharge characteristics of batteries, and can also be used as dual channel electronic load, current source, or power supply.

Inside [K.C.]’s device are all the tools required for charging and discharging lithium-ion, lead acid, and NiMH batteries. He’s doing this with a few slightly unusual circuits, including a SEPIC DC to DC converter, and an ‘analog’ PWM controller. these two techniques together mean [K.C.] can get away with smaller caps and inductors in his design, which also means less ripple on the output. As far as battery chargers and dischargers go, this one is very well designed.

Control of battery discharging and charging happens through a SILabs 8051-based microcontroller with USB. The UI is a simple Nokia LCD and an app running in Windows. If you want to save the world, this isn’t the project for you. If you need to test a few rechargeable batteries, this is a great device to have on the workbench.

The 2015 Hackaday Prize is sponsored by:

Where Are They Now: Terrible Kickstarters

Kickstarter started out as a platform for group buys, low-volume manufacturing, and a place to fund projects that would otherwise go unfinished. It would be naive of anyone to think this would last forever, and since these humble beginnings, we’re well into Peak Kickstarter. Now, Kickstarter, Indiegogo, and every other crowdfunding platform is just another mouthpiece for product launches, and just another strategy for anyone who needs or wants money, but has never heard of a business loan.

Of course there will be some shady businesses trying to cash in on the Kickstarter craze, and over the last few years we’ve done our best to point out the bad ones. Finding every terrible Kickstarter is several full-time jobs, but we’ve done our best to weed out these shining examples of the worst. Following up on these failed projects is something we have been neglecting, but no longer.

Below are some of the most outrageous Kickstarters and crowdfunding campaigns we’ve run across, and the current status of these failed entrepreneurial endeavors.

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