They crush ’em. They pierce ’em.
They roast ’em, soak ’em in saltwater and brief circuit ’em.
They overcharge and even over-discharge ’em. Heck, they’ll even shoot them with lasers.
These poor batteries by no means actually stand an opportunity towards Sandia Nationwide Laboratories researchers whose job is to check the cells past their limits.
And now, with a brand new indoor tower that enables battery-abuse researchers to drop 200 kilos or extra on the out-matched lithium-ion cells, they’ve created yet one more option to be taught much more about how batteries reply to stress.
“This turns into our ninth approach of killing a battery,” mentioned Sandia battery-abuse testing engineer Chris Grosso. “It hits with a lot drive that to date we’re simply chopping the batteries in half.”
Lithium-ion batteries are mostly present in electrical vehicles, computer systems, medical tools and plane. And they’re getting extra highly effective on a regular basis. The fixed push for extra storage and energy drives the necessity for assessments equivalent to these supplied by the brand new drop tower, mentioned Sandia mechanical engineer June Stanley.
“So far as we all know no one within the U.S. has completed any drop assessments for influence testing like this,” Stanley mentioned. The information collected will help trade in growing safer, extra dependable batteries with extra environment friendly efficiency. It’s going to additionally assist in responding to emergencies, equivalent to electric-vehicle crashes, she mentioned.
“An influence check like that is extra actual world, extra reasonable to what would occur,” she mentioned. “The check may give us a greater understanding for first responders and the way they deal with an emergency. It will also be useful for trade researching and growing new expertise.”
Gravity takes over
The drop tower looms inside a hangar-type constructing that simply could be vented and cleared if there’s smoke from a battery fireplace. Researchers management the tower remotely and watch the motion on screens inside a trailer parked about 30 yards away.
What they see is the drop tower reaching upward to only under the 14-foot ceiling. A battery sits in a metal tray bolted to a load cell to measure the influence drive on the base of the tower as a weight of at the very least 200 kilos is perched above at heights as much as eight ft, eight inches.
The push of a button unleashes the load. Gravity takes over, adopted by a violent collision of weight onto battery. Wires related to the battery and the tower measure velocity, drive, temperature and voltage. Cameras file the influence and ensuing carnage. Knowledge flashes to computer systems within the trailer.
Thus far, the group has examined single-cell lithium-ion batteries and a 12-pack of such batteries taped collectively. Whereas, the assessments haven’t produced the sparks and warmth that will happen in a slower-moving hydraulic crush check, they’ve collected helpful knowledge, Stanley mentioned.
Within the aftermath of the drop, the batteries are unstable and the security standing of about half the cells is unknown, she mentioned. “It actually helps with a greater understanding for first responders to deal with a state of affairs like that.”
Testing results in enchancment
The utmost weight that can be utilized to smash, crush or chop a battery is 500 kilos due to the parts chosen, Grosso mentioned. “That may simply be upgraded, if wanted, and we will maintain including weight to get extra drive.”
Welded tube metal and off-the-shelf rails and bearings make the drop tower low cost to take care of, even when lower than elegant to take a look at, mentioned Grosso, who designed the tower’s electronics and working software program.
“When the inevitable fireplace comes, elements could be changed cheaply,” he mentioned. “It doesn’t should be fairly, nevertheless it does should be efficient, and we have now to have the ability to justify the price to our clients.”
Stanley joined with Grosso about 2½ years in the past and improved the mechanical design, security and engineering controls to maneuver the tower from thought to actuality. Stanley, who spearheaded the manufacture and set up of the drop tower, mentioned the group plans to enhance the contraption as extra assessments are carried out and clients ask for several types of assessments.
“That is simply the bottom design,” she mentioned. “Now we have hopes and plans to enhance on it.”
Future enhancements shall be so as to add springs or gas-pressurized pistons to spice up the downward acceleration of the load, growing the influence drive.
“To get extra influence drive we will improve the mass or the acceleration of the thing impacting the battery, or each,” Stanley mentioned. “Proper now, we’re accelerating on the charge of gravity. Our objective is to have a a lot increased charge of acceleration, thus extra drive!”
Different plans will develop as trade continues to push the envelope on the facility that batteries can produce and retailer. And as these batteries work their approach into extra on a regular basis units, Sandia researchers will proceed to get higher at abusing them.
It’s that itch to push batteries previous their limits that can finally push growth. The extra knowledge accessible, the higher builders can design the subsequent technology of vitality storage units with improved efficiency, reliability and security.
“As an added functionality to what we’re already doing, the drop tower may be very cool,” Grosso mentioned. “Our clients have been asking for one thing like this, and it simply exhibits that we have now received some critical mind energy in our lab.”