3-D Zinc Sponge Could Wipe The Energy Storage Floor With Li-ion Batteries (CleanTechnica Interview)
May 15, 2017
A team of researchers from the Naval Research Laboratory is on to a new zinc-based alternative to lithium-ion batteries. The new research aims at enabling the Navy to expands its energy storage options. The new zinc battery could also makes its way into the EV market, providing manufacturers with a lighter, less expensive alternative to today’s crop of lithium-ion batteries.
Head researcher Debra Rolison, who has been at NRL since 1980, graciously spent some time on the phone last week with CleanTechnica along with her colleague Jeffrey Long to provide some unique insights into the breakthrough.
he Navy’s problem with lithium-ion batteries is that they are not considered safe for some applications on ships as well as other facilities due to fire risks.
Don’t get the wrong idea about EV battery safety, though. Modern lithium-ion battery packs are designed with control systems that prevent overheating and provide for a longer lifespan.
Rolison underscored that you’re only going to get safety failure in a poorly designed control system — hoverboards being one notorious example. That kind of problem has practically zero chance of occurring in today’s intensely regulated auto market.
The safety issue does present an obstacle to designing lighter, less expensive energy storage systems, as Rolison explained:
“Lithium-ion thermal management has to be designed in. With other safeguards, these energy management systems add weight, volume, and cost.”
Rolison also noted that thermal management systems add complexity to the manufacturing end of things.
Throw in the additional supply chain complications and you can see why researchers have been pursuing an energy storage system that can safely ditch thermal management systems.
Those of you familiar with zinc batteries may be scratching your heads at this point. Though common for single-use batteries, zinc is not the first thing that comes to mind when you’re thinking of rechargeable batteries.
Nevertheless, researchers have been hot on the trail of zinc as an alternative to lithium-ion for a while now.
In addition to the weight and cost advantages, supply chain security is a big consideration. Zinc can be found in many parts of the world and it is abundant in the US. In contrast, lithium mines are few and far between. That could change, eventually, but for the here and now, lithium supply seems like an issue.
“Batteries have to be inexpensive and scalable, and also zinc is not a strategic metal,” Rolison explained. “It can be found anywhere.”
The obstacle is that zinc is a tricky beast as applied to rechargeable batteries. During the charge/discharge cycle, zinc batteries form nanoscale spikes called dendrites that severely limit performance and lifespan.
Researchers have been looking at various solutions — for example, Stanford University has had a zinc-air battery in the works for a while, and just last year Pacific Northwest National Laboratory came up with a zinc-manganese combo for stationary energy storage.
Now, it looks like the Navy is beating them all to the punch.