Tesla’s New Tabless Batteries Unlock New Levels Of Performance

October 5, 2020 by Lewin Day 104 Comments

Telsa are one of the world’s biggest purchasers of batteries through their partnerships with manufacturers like Panasonic, LG and CATL. Their endless hunger for more cells is unlikely to be satiated anytime soon, as demand for electric cars and power storage continues to rise.

As announced at their Battery Day keynote, Tesla has been working hard on a broad spectrum of projects to take battery technology to the next level in order to reach their goal of 3 TWh annual production by 2030. One of the most interesting aspects of this was the announcement of Tesla’s new tabless 4680 battery, which will be manufactured by the company itself. Let’s take a look at what makes the 4680 so exciting, and why going tabless is such a big deal. Continue reading “Tesla’s New Tabless Batteries Unlock New Levels Of Performance” →

Building A USB-C Charger For Canon NB-4L Batteries

September 23, 2020 by Tom Nardi 17 Comments

One of the most appealing aspects of USB-C is that it promises to be a unified power delivery system. You’ll no longer need to have a separate power cords for for your phone, camera, and laptop; physically they’ll all use USB-C connectors, and the circuitry in the charger will know how much juice to send down the line for each gadget. But in reality, we’ve all got at least a few pieces of older equipment that we’re not about to toss in the trash just because it doesn’t support the latest USB spec.

Case in point, the old Canon camera that [Purkkaviritys] modified to take infrared pictures. Instead of abandoning it, he decided to make a custom USB-C charger for its NB-4L batteries. Since they’re just single cell 3.7 V lithium-ions, all he had to do was wire them up to the ubiquitous TP4056 charger module and design a 3D printed case to hold everything together.

He did go the extra mile and replace the SMD charging indicator LEDs on the PCB with 5 mm LEDs embedded into the 3D printed enclosure, though you could certainly skip this step if you were in a hurry. We imagine if you print the enclosure in a light enough color, you should be able to see the original LEDs glowing through the plastic.

This project is yet another example of how incredibly useful the TP4056 module really is. If there’s even a chance you might want to build a rechargeable gadget in the near future, you should have a few of these cheap boards ready to go in the parts bin.

Potential Contenders For Battery Supremacy

September 1, 2020 by Lewin Day 47 Comments

Lithium ion batteries have been a revolutionary technology. Their high energy and power density has made the electric car a practical reality, enabled grid storage for renewable energy, and put powerful computers in the palm of the hand. However, if there’s one thing humanity is known for, it’s always wanting more.

Potential contenders for the title of ultimate battery technology are out there, but it will take a major shift to dethrone lithium-ion from the top of the tree.

Dominant For Good Reason

Lithium-ion batteries were first developed by Stanley Whittingham, working at Exxon, who were looking to diversify away from oil in the midst of the major energy crises of the 1970s. Over the years, the technology was developed further, with work by John Goodenough (a superb hacker name if we’ve ever heard one) and Akira Yoshino increasing performance with improved cathode and anode materials. Commercialization was first achieved by Keizaburo Tozawa, working at Sony to develop a better battery for the company’s line of camcorders. Continue reading “Potential Contenders For Battery Supremacy” →

Ammo Can Battery; 50 Ah LiFePO4 Clad In Army Green

March 30, 2020 by Mike Szczys 23 Comments

For the price of a mid-range Android phone, [Kenneth Finnegan] turned a 50 caliber ammo can into a 50 amp-hour portable power supply. The battery pack uses four 3.5 V LiFePO₄ cells wired in series to achieve a nominal 12 V supply that stands in for a traditional lead-acid battery. The angel of second-hand purchases was smiling on this project as the cells were acquired on eBay in unused condition, complete with bus bars and mounting spacers. All it took to fit them in the case was to grind off the spacers’ dovetails on the outer edges.

There are many benefits to Lithium Iron Phosphate chemistry over traditional lead acid and [Kenneth] spells that out in his discussion of the battery management system at work here. While the newer technology has a much better discharge curve than lead-acid, there’s a frightening amount of power density there if these batteries were to have a catastrophic failure. That’s why there are Battery Management Systems and the one in use here is capable of monitoring all four cells individually which explains the small-gauge wires in the image above. It can balance all of the cells to make sure one doesn’t get more juice than the others, and can disconnect the system if trouble is a-brewin’. Continue reading “Ammo Can Battery; 50 Ah LiFePO4 Clad In Army Green” →

Hybrid Supercapacitors Are — Well — Super

March 14, 2020 by Al Williams 39 Comments

Kurt.energy is promoting a new line of hybrid supercapacitors. By itself, that wouldn’t be very newsworthy, but the company claims these graphene-based supercapacitors merge the best features of both supercapacitors and lithium-ion batteries. Based on technology from a company called Shenzhen Toomen New Energy, the capacitors are optimized for either high energy or high power. They can reportedly charge and discharge 10-20 times faster than lithium-ion batteries. Of course, we’ve heard wild claims surrounding graphene capacitors before and, so far, they haven’t seemed very credible.

In addition to high performance, the company claims the capacitors are safe from overcharging, short circuit, and other safety issues that plague batteries. The devices are said to operate — including charging — from -40C to 80C. You can see a video from the company, below.

Continue reading “Hybrid Supercapacitors Are — Well — Super” →

The Quest To Find A Second Life For Electric Vehicle Batteries

February 1, 2020 by Roger Cheng 49 Comments

Rechargeable lithium chemistry battery cells found their mass market foothold in the field of personal electronics. The technology has since matured enough to be scaled up (in both physical size and production volume) to electric cars, making long range EVs far more economical than what was possible using earlier batteries. Would the new economics also make battery reuse a profitable business? Eric Lundgren is one of those willing to make a run at it, and [Gizmodo] took a look at his latest venture.

This man is a serial entrepreneur, though his previous business idea was not successful as it involved “reusing” trademarks that were not his to use. Fortunately this new business BigBattery appears to be on far more solid legal footing, disassembling battery packs from retired electric vehicles and repacking cells for other purposes. Typically EV batteries are deemed “worn out” when their capacity drops below a certain percentage (70% is a common bar) but that reduced capacity could still be useful outside of an EV. And when battery packs are retired due to problems elsewhere in the car, or just suffering from a few bad cells, it’s possible to extract units in far better shape.

We’ve been interested in how to make the best use of rechargeable lithium batteries. Ranging from tech notes helping battery reuse, to a comparison of different types, to looking at how their end-of-life recycling will be different from lead-acid batteries. Not to mention countless project wins and fails in between. A recurring theme is the volatility of mistreated or misbehaving batteries. Seeing a number of EV battery packs stacked on pallets and shelves, presumably filled with cells of undetermined quality, fills us with unease. Like the rest of California, Chatsworth is under earthquake risk, and the town was uncomfortably close to some wildfires in 2019. Eric is quick to give assurance that employees are given regular safety training and the facility conforms to all applicable workplace safety rules. But did those rules consider warehouses packed full of high capacity lithium battery cells of unknown quality? We expect that, like the business itself, standards for safety will evolve.

Concerns on safety aside, a successful business here would mean electric vehicles have indeed given battery reuse a profitable economy of scale that tiny little cell phone and laptop batteries could not reach. We are optimistic that Eric and other like-minded people pursuing similar goals can evolve this concept into a bright spot in our otherwise woeful state of e-waste handling.

A Safer, Self-Healing Polymer Battery

January 15, 2020 by Sharon Lin 4 Comments

Lithium-ion batteries are notorious for spontaneously combusting, with seemingly so many ways that it can be triggered. While they are a compact and relatively affordable rechargeable battery for hobbyists, damage to the batteries can be dangerous and lead to fires.

Several engineers from the University of Illinois have developed a solid polymer-based electrolyte that is able to self-heal after damage, preventing explosions.The material can also be recycled without the use of high temperatures or harsh chemical catalysts. The results of the study were published in the Journal of the American Chemical Society.

As the batteries go through cycles of charge and discharge, they develop branch-like structures known as dendrites. These dendrites, composed of solid lithium, can cause electrical shorts and hotspots, growing large enough to puncture internal parts of the battery and causing explosive chemical reactions between the electrodes and electrolyte liquids. While engineers have been looking to replace liquid electrolytes in lithium-ion batteries with solid materials, many have been brittle and not highly conductive.

The high temperatures inside a battery melt most solid ion-conducting polymers, making them a less attractive option for non-liquid electrolytes. Further studies producing solid electrolytes from networks of cross-linked polymer strands delays the growth of dendrites but produces structures that are too complex to be recovered after damage. In response, the researchers at University of Illinois developed a similar network polymer electrolyte where the cross-link point undergoes exchange reactions and swaps out polymer strands. The polymers stiffen upon heating, minimizing the dendrite problem and more easily breaking down and resolidifying the electrolyte after damage.

Unlike conventional polymer electrolytes, the new polymer also shows properties of conductivity and stiffness increasing with heating. The material dissolves in water at room temperature, making it both energy-efficient and environmentally friendly as well.