Scientists develop safer, more durable lithium-ion battery that can operate under extreme conditions

Scientists develop safer, more durable lithium-ion battery that can operate under extreme conditions

Lithium-ion batteries have become the energy storage method of choice for consumer electronics and military and aerospace systems alike. But potential safety hazards associated with the organic electrolytes that are used in Li-ion battery cells remain an ongoing concern.

Remember those reports of exploding hoverboards a few years ago? The culprit behind those spontaneous electrical combustions were low-quality Li-ion batteries, which contain highly flammable, toxic, and moisture-sensitive electrolytes.

But a team of scientists at the Johns Hopkins Applied Physics Laboratory has partnered with researchers from the University of Maryland and the Army Research Laboratory to develop a new type of flexible lithium-ion that is not hazardous and can operate under extreme conditions including cutting, submersion, and ballistic impact.

In their paper, "Flexible Aqueous Li-ion Battery with High Energy and Power Densities," which was published online last month in Advanced Materials, the scientists describe their work, which builds upon a novel, highly-concentrated water-based electrolyte called "water-in-salt" that can address the instability of traditional Li-ion batteries.

The team operated their flexible Li-ion battery in open air with minimal packaging, using only some electronically insulating, heat-resistant tape to keep it in place. In their demonstration, the battery powered a significant motor load without any concerns. To demonstrate the full safety potential, the team performed a series of tests while the battery was in operation, including cutting it, immersing it in sea water, and subjecting it to ballistic testing at an APL facility. None of these tests would be possible with traditional Li-ion batteries.

Credit: Applied Physics Lab

Impressively, not only did these abuse tests cause no catastrophic failure, but the battery maintained its performance and continued to power the load even when damaged and completely exposed to air and water.

The extraordinary safety of the water-in-salt electrolyte stems from the fact that the water is strongly bound to the high concentrations of salt, and that the electrolyte is slightly hydrophobic—meaning it repels water.

The team is looking for opportunities to transition the technology to make it available to the military.

"We wanted to show the real implications of this technology in practical applications," said Kostas Gerasopoulos, senior research scientist and principal investigator at APL. "Particularly for our military, with our [soldiers] exposed to extreme conditions and environments during their missions, the capability to maintain both safety and performance is unprecedented,"

The current generation of flexible batteries shows considerable potential, but they are still in the prototype phase.

"We want to increase the robustness of the [] and the energy density of the batteries even further," Gerasopoulos said. "This work though proves the concept that we can build safe Li-ion batteries that can survive mechanical abuse."


Explore further

Water-based lithium-ion batteries without explosive risks now a reality

More information: Chongyin Yang et al. Flexible Aqueous Li-Ion Battery with High Energy and Power Densities, Advanced Materials (2017). DOI: 10.1002/adma.201701972
Provided by Johns Hopkins University
Citation: Scientists develop safer, more durable lithium-ion battery that can operate under extreme conditions (2017, November 10) retrieved 20 November 2018 from https://techxplore.com/news/2017-11-scientists-safer-durable-lithium-ion-battery.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
895 shares

Feedback to editors

User comments

Nov 10, 2017
kool well its got good power output, but the density is about 60 percent of the car batts for the same weight. so we need 180 percent better density until its commercially viable.

Nov 10, 2017
The video seems fake, considering what they're claiming for the properties of the battery.

They're claiming over 20 kilowatts per kg specific power, which is huge since other li-ion batteries achieve 200-500 Watts per kg, or ten times less. This battery is capable of putting out some serious short circuit currents.

Yet when the metal scissors cut through the battery and short circuit it, which they must, there's no reaction. Not even a whiff of smoke. The claims seem too incredible to be true, and the video looks a bit fake, like the battery was already split in half inside the pouch at the crease where they bent it, and the cutting was done on the lower half which contains no actual battery.

Nov 10, 2017
The least you would expect to happen is for the motor to stop, because the scissors cut through both electrodes at the same time and complete the circuit, which is the same thing as shorting the wires to the motor.

If not, that would mean the electrodes in the battery have a massive internal resistance which allows one half of the battery to continue powering the load while the other end is being shorted out, but that would mean the specific power output claims are plain bull.

I'm calling it a trick. The question is, why would Johns Hopkins Applied Physics Laboratory lie like that?

Nov 11, 2017
", but the density is about 60 percent of the car batts for the same weight. so we need 180 percent better density"

As noted in the article these are for extreme conditions - not car batteries.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more