Battery Engineering Hack Chat is Recharged

Step back in time a few decades, and the only time the average person would have thought much about batteries was when the power went out, and they suddenly needed to recharge their flashlight. pocket or his portable radio. But today, high capacity batteries have become an integral part of our increasingly digital lifestyle. In fact, chances are the device you're reading this on is currently running on battery power, or at least capable of it.

So let's get to know batteries better. What is the chemical process that allows them to work? Besides, what is a battery in the first place?

These questions, and more, made up this week's Battery Engineering Hack Chat with Dave Sopchak. Our last Hack Chat of 2022 ended up being one of the longest in recent memory, with the conversation beginning over an hour before the scheduled kickoff and continuing another half hour after the time the master of ceremony Dan Maloney officially delivered his closing remarks. Not bad for a subject that is so often taken for granted.

Dave Sopchak

Somewhat counter-intuitively, the Battery Engineering Hack Chat actually started with a lively discussion about fuel cells - a topic that Dave also has considerable experience with. Considering they powered the Apollo missions to the Moon in the 1960s, you would think they would now be integrated into the old Wagon Queen Family Truckster.

The reality is that we don't have the hydrogen delivery network that would make these vehicles practical, but of course no one is going to build that network unless there's a demand, so that's a recurrent issue. As for the fuel cells powering our homes, Dave points out that these units tend to run on natural gas, which makes them unattractive given the strong push toward renewable resources.

From there, the topic shifts to supercapacitors, which in turn leads to a discussion of what a battery is and isn't. Surely the average Hackaday reader knows that a capacitor and a battery are conceptually similar in that they store energy, but that's where the comparison ends. As Dave explains, to be considered a real drum, there has to be a chemical reaction. While we may not realize it, there's actually quite a bit going on inside that indescribable lithium-ion pouch; the positive and negative electrodes will change considerably in volume when passing from a discharged state to a charged state, the product of oxidation and reduction.

Dave goes on to say that the inherently dynamic nature of batteries is why he takes issue with the so-called "solid-state batteries" that many hope will provide the next generation of portable power. A true solid-state component, that is, a solid-state device with no moving parts, would not experience volume changes during use. So, because the electrodes inside a battery undergo oxidation or reduction, they cannot, by definition, be in a solid state.

Dave says that...