Lithium Polymer (Li-Po) Battery Technology
When I heard the term "lithium-polymer" (or Li-Po) for the first time while learning about and discussing drones, I didn't quite know what it was. Obviously it is a lithium battery in my mind. I use many small electronic devices such as smartphones and laptops in my daily routine, so I have heard of Lithium-Ion (or Li-Ion) batteries before. As a raging DIY'er I also use many cordless battery-powered tools such as saws, drills, and sanders. Some of those older tools use nickel-cadmium (Ni-Cad) or even nickel-metal-hydride (Ni-MH) batteries. The newer ones however, all use Li-Ion. I simply assumed that Li-Po was a new technological offshoot that I had not heard of previously. So in order to learn as much as I can about "stuff", and in accordance with my own curiosity, I set out to learn what a polymer battery was, and also what it isn't. What I came up with was actually quite surprising!
A few weeks ago, I picked up a couple from a bar in Fort Worth who were a little too drunk to drive. On the way to their destination, I learned that the the woman was an account rep for Milwaukee tools, and we had a rather engaging conversation about power tools that I would not have expected to have with a woman in her twenties! She knew all about Li-Ion, so I asked about Li-Po, and she said it was a scam (I assume she used that word given her inebriated state). She essentially communicated to me that Li-Po is actually a new technology that was still being developed which would replace the electrolytic fluid with a polymer. The result would be a safer and lighter battery. The problem is that it is still being researched and developed,and that a true Li-Po battery hasn't hit the market yet. I decided to research further at a later time and realized she was completely correct!
Fast forward a week or so, and Zach and I are flying the DJI Phantom up at Turner Falls, and I think to myself "If a true Li-Po battery doesn't exist on the market, then what am I holding in my hand?" It says Li-Po, is someone lying to me? As we have seen before, sometimes the market demands a technology before it is even available. Sounds impossible in theory, but it really isn't when it comes to the consumer market. Think back nearly 20 years ago when we all had 100-pound standard definition televisions in our homes, and unless it broke, we had no reason to replace it. We all knew HD was coming, but it wasn't going to be here for many years. That certainly did not stop the manufacturers from selling "HD-Ready" televisions for nearly a decade that really had no additional functionality than the TV's we already owned. We all certainly fell for it though! We were ready for HD! (not really lol)
So here's the skinny, Li-Po is a great idea, it will make batteries lighter because with an electrolytic composite it no longer needs a metal container to contain the liquid. They will also be safer because the polymer will be more stable than the liquid and not nearly as prone to destabilizing and exploding. So... what are we flying our drones with? We are flying our drones with Li-Ion batteries that are wrapped in a polymer shell. That's right! The electrolytic liquid is gelled only slightly to be a little more stable and then wrapped in a 'polymer' container that allows us to have flat or oddly shaped batteries without all those metal containers inside of it to hold liquid. They may call it Lithium-Polymer but not for the exact reasons we would expect. Due to an increased manufacturing cost, Li-Po is really only advantageous when battery weight is of the utmost concern, so it is a natural choice for drone use. It's higher cost, however, doesn't justify the marginally lighter technology in laptops and other electronics where weight might be of concern but the cost is of greater concern.
We saw unprecedented technological advances in recent years in battery tech because of the explosion of mobile phone use over the past 20 years. I believe the drone industry will carry the technology even further down the road.
For those interested in additional information on Lithium-Polymer batteries, check out the Wikipedia link.