Batteries are more important than ever before. They’ve already fueled the mobile revolution, and now they’re poised to transform the transportation industry and the power grid.
The batteries in modern devices are under immense pressure; they need to store, charge, and discharge lots of energy in high-density configurations. The stakes are incredibly high. We’ve seen dangerous and expensive recalls play out. Remember the Samsung Galaxy Note 7 fiasco a few years ago? That recall not only directly cost the company billions of dollars, but it also took an incalculable toll on Samsung’s reputation.
With the world turning to electric vehicles, automotive manufacturers have faced serious challenges with battery processes and have had to stage several large, costly EV recalls over battery concerns.
This webinar shows how Lumafield’s industrial CT technology can help you avert these kinds of costs by inspecting batteries before they go out to consumers, allowing you to stop invisible problems from becoming full-blown disasters.
We start by using our Voyager software to examine 3D reconstructions of familiar alkaline batteries: the AAA and 9V. Inside each cell, CT reveals the high-density brass or copper pin that pierces into a powdered zinc core, surrounded by an outer layer of manganese dioxide. Scans make it easy to assess the integrity of the pin and determine if there’s any zinc spillage. Our scan of the 9V battery shows 6 AAAA cells packed inside, all of which vary slightly from one another in these respects.
Next we use Voyager to look inside an 18V lithium-ion power tool battery pack. We can clearly see the individual cells nestled inside a ribbed injection-molded plastic housing. With CT, you can validate the placement and fit of the batteries, as well as determine if there’s any interference or risk of damage.
Changing Voyager’s range mapper settings allows the battery pack’s metallic components to really jump out. We can see the spring that operates the latch on the battery. An engineer has clearly done their homework and ensured the correct length of the screws. Our section view and linear measurement tool show a good safety margin of 1.6 millimeters between the screw and battery cells.
Below is a CT scan of a high-quality LG21700 lithium-ion cell. It shows clearly how the separators at the top of the cell are evenly lined up. Thin layers of electrode with slightly taller separator layers are all wound around the central core. We also find metallic electrodes running through the middle.
Below is a look at Voyager’s automated measurements tool. We define an inspection plane in the object and see that the outside diameter of the can is almost exactly 21 millimeters. The 21-millimeter can diameter and 70-millimeter length gives you that 21700 metric, and LG delivered these dimensions. We can also resolve very fine details, like the pitch between the separator layers of this winding, which we see is 340 microns.
Next, we delve into a lithium-ion pouch cell. These are everywhere, from toys to handheld electronics. They come in all shapes and sizes, offering high energy density. However, these cells are very fragile, making them perfect candidates for CT inspection. Inside, you’ll find a tightly-wound sandwich of electrodes and separators. There’s a little circuit board across the top where the electrodes—the anode and cathode—are soldered on.
Unlike the cylindrical LG21700 cell, it doesn’t have armor, making it susceptible to damage. There’s also a high risk of manufacturing defects around the edges of the cell where the thin foils are especially delicate. A tiny pinch could easily tear that foil and create a short circuit.
This particular battery is functional, but you can see some interesting defects. In the slice view below, there’s a tiny separation at the bend between the electrode and separator layer. This doesn’t seem to be an immediate problem, but this might be an area that needs more attention if it appears in a large percentage of batteries from this production line.
This SRAM lithium-ion battery is from an electronic shifter on a bike. It’s a great example of the challenges that go along with integrating a battery into a product.
This is a rechargeable battery pack that would be mounted to the frame of a bike and provide power to the electronic shifters. This view of the cells shows you the circuit board and the tabs that connect to it. The washer-like structure on the bottom is part of a mechanical indicator switch on the outside.
You can see inside the housing there are two lithium-ion pouch cells. This battery is unique among items scanned in this webinar in that it’s potted to help it withstand a high-vibration, high-moisture environment.
Potting is a reliable way to protect your batteries and also an ideal application for CT because potting makes subsequent inspection impossible. Our scan shows air bubbles and gaps in the potting.