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David Yeung, co-founder and CEO of Lionrock Batteries, discusses previous projects—including smartwatch straps—and his collaboration with the Nano and Advanced Materials Institute (NAMI) in Hong Kong on wearable, flexible battery technology at CES 2019.
Nolan Johnson: David, could you tell us a little bit about you and what your company does?
David Yeung: I have been in the wearable industries for a few years. Before this project, I ran a smartwatch strap project attempting to include some functions and battery power within the flexible watchstrap part itself. During that course, I discovered flexible battery background technology being developed by the NAMI. I have engaged with them on research and development to refine the flexible battery. The project concluded in 2016, and then we started Lionrock Batteries in 2017 to commercialize this technology, which I think was amazing.
Johnson: Where is Lionrock located?
Yeung: Hong Kong, as is the NAMI.
Johnson: Can you tell me a little bit about this battery technology?
Yeung: It is a nanofiber structure battery, which is very reliable, durable, and highly porous; thus, you practically avoid the battery from being short-circuited. If we deform it, fold it, or cut it, the battery remains safe. That’s a main feature of the battery. It’s so safe that we can make it deformed and bendable, so it’s a flexible battery.
Johnson: What are the specifications for this battery?
Yeung: It can charge and recharge 1,000 times with very high energy of retention.
Johnson: And you have a couple of examples of that battery here in front of us where the battery is embedded in a plastic rubber watchband like you would use for a smartwatch. If I have this battery built into my watch band—I can feel it all the way down the band—how much charge do I get out of it and add lifetime to my watch?
Yeung: You are looking at one section of the watch strap, but watch straps have two sections. Each section has approximately 80–100 mAh (miliamp-hours). If they are both wrapped with a battery, that’s around 180 mAh. To give you an indication, I believe an Apple iWatch battery is about 200+ mAh. If you have this watch strap integrated into an Apple Watch, it can run from one to two days now to three to four days, which is nearly double the capacity.
Johnson: Or for the same battery life, you could move the batteries into the band and free up room inside the case for additional function.
Yeung: Yes, which is quite a lot. And by the way, for each smartwatch, typically it has about 50% of the watch body compartment contributed to the battery. So, if you can place the battery outside the watch, the watch can probably be half the size.
To read the full article, which appeared in the April 2019 issue of SMT007 Magazine, click here.