Supercapacitors power the Note 9 stylus — but are they ready to replace batteries?

Samsung’s latest Galaxy Note 9 has a nifty new feature: for the first time, the S Pen stylus has Bluetooth and can be charged instantly using a supercapacitor. Sticking the S Pen into the phone for 40 seconds gives it enough juice for 30 minutes of use, so battery life should no longer be a worry. But how exactly does this technology work? And what else could we use supercapacitors for?

Supercapacitors (or ultracapacitors) store energy and, in some ways, are the opposite of batteries. Batteries can hold a decent amount of energy but take a long time to charge, explains Thomas Miller, a materials scientist with the Electrochemical Innovation Lab at University College London. Supercapacitors charge so fast it seems instantaneous, taking just seconds or minutes versus hours. But they hold only a tiny amount of energy. Imagine getting shocked by static electricity — it happens very fast, but there’s only a little bit of shock.

Supercapacitors work like normal capacitors — by accumulating electrical charge on their surface — but at a bigger scale. They consist of two metal plates, one with a positive charge and one with a negative charge. These metal plates are surrounded by a solution of positive and negative ions, which build up on the plates during charging to deliver electricity. That means that the amount of energy supercapacitors hold is very dependent on how big the plates are — which isn’t very convenient when we want our electronics to be small. (As Miller says: “You wouldn’t want to have a backup phone battery the size of a Coke can.”) But they do have one other big advantage: You can charge for thousands and thousands of cycles without degrading the way lithium-ion batteries do.

Because of these features, Yury Gogotsi, a supercapacitor expert at Drexel University, calls the Samsung stylus a “good development.” Theoretically, you’re often using the stylus if you own a Note, so the rapid-charge feature makes sense. Plus, the stylus needs to be charged again and again, and that would degrade a normal battery but not the supercapacitor.

“Supercapacitors will live longer than the phone itself,” says Gogotsi. “And most people will probably lose the stylus long before that” — which is what happened to him last time he had an S Pen.

In the world of energy storage research, batteries get most of the funding and interest, but scientists are trying to find ways to make supercapacitors store more energy. One approach, says Gogotsi, is to build them using promising materials that might be able to store more energy. Graphene is one example of such a material. Gogotsi’s group is working on another promising material, called transition-metal carbides. Other scientists are trying to combine batteries and supercapacitors.

While we’re waiting for the breakthrough that would make small supercapacitors hold as much energy as batteries, there are plenty of possible applications. They could be used for personal electronics that don’t need to be on constantly, like cleaning robots or power tools — “anything with downtime,” says Miller.

There’s a lot of interest in supercapacitors for electric vehicles, and Tesla’s CEO has said that supercapacitors, not batteries, will be the technology that really changes the industry. Already, Shanghai has a network of buses that run on supercapacitors called “capa buses.” At each stop, the bus charges the supercapacitor, and that gives it enough energy to drive for 10 or 15 minutes to the next stop.

Still, it seems unlikely that we’ll see supercapacitor-only cars, according to Miller. It takes an enormous amount of infrastructure for it to work in a city, and most likely it won’t be reliable with electric vehicles that need to go hundreds of miles at a time without charging.

But supercapacitors could be used with batteries to smooth the power fluctuations. Plus, batteries are damaged by charging and discharging quickly — like stopping and starting at traffic lights. If carmakers paired a battery with a supercapacitor, the supercapacitor could take over during these starts and spots. It’d quickly deliver some energy, reducing battery wear and extending its life.

Ultimately, for supercapacitors to take off, there needs to be more investment in research. “There’s been an explosion of battery research, but it’s only in the past few years that supercapacitors have been investigated more,” Miller says. “Supercapacitors are a materials challenge and we still need more fundamental understanding.”

Charging has changed how I interact with friends

Every few weeks, I head up to Connecticut with five or six close friends or family members and some newfangled gaming laptop for a LAN party. Most of my gaming clan are like family to me, so we often share or loan charging peripherals. When everyone in the house needs to charge a controller, a Nintendo Switch, or some other piece of technology, spreading the energy around becomes a necessity.

Ideally, everyone in our gaming clan would only be sharing USB-C cables to charge our devices. But our LAN party reflect the industry: we’re not there yet.

There isn’t a high-end gaming laptop that doesn’t use its own proprietary charging plug. Sometimes that’s a design choice by the OEM or the physics of energy transfer getting in the way, thus making it harder to use USB-C instead of some odd plug that I won’t ever see on another laptop.

Developments in fast and wireless charging tech over the past decade have improved all of our favorite gadgets, making for less frequent visits to a wall outlet. Recently, fast charging has played a big role in that by making it easier to quickly juice up a battery and get moving again through the proliferation of USB-C.

USB-C promised to be “the cable to charge them all.” USB-C consists of the Type-C standard cable itself, as well as Thunderbolt 3, USB-PD, and the different generations that affect how quickly you can charge with the cable. The proliferating styles can be confusing for consumers.

Once you figure out the cables you’re using, you’ll have to face a ton of heavily marketed fast charging standards, all with different charging rates. Apple’s fast charging, Qualcomm’s Quick Charge, OnePlus’ Dash charging, Motorola’s TurboPower — it can feel like chaos.

Here’s why it matters.

My gaming clan might not play Fortnite on mobile — we’re a PC, PS4, and Switch kinda group. But if we did, I’m quite sure we’d redesign the game room to have several USB-C cables, so we can be ready for those moments where a dispute can only be resolved with a 1v1 game of Dragon Ball FighterZ on the Switch.

Thankfully, things are less complicated when it comes to charging our phones.

Most Android smartphones have Quick Charge 4.0 or a competing tech with similar wattages, like OnePlus’ Dash charging, or Samsung’s Adaptive Fast Charging. If the device in question is an LG or Samsung smartphone, then you’ll also have the benefit of wireless charging. For iOS users, the iPhone X, 8, and 8+ have their own fast charging solution around USB Power Delivery bricks you can buy alongside Apple’s own Lighting to USB-C cable. Earlier models have some workarounds, too.

But not all accessories are made the same — use the wrong one, and you can permanently ruin your battery. Just so we’re clear: do not buy cheap, off-brand accessories! A bad cable can over-volt or potentially overcharge a battery, eventually damaging it.

What about the future of batteries and charging? Over a heated game of League of Legends, my friends and I discussed if there might be a way through by storing and transferring energy in a way that doesn’t use chemical reactions, like a traditional lithium-ion battery does. That would mean using supercapacitors, which store energy on the surface of a material. The upside is that they can be charged very quickly and retain energy storage capacities over time. They don’t wear out, like ordinary batteries do. The only catch is that they’re taking a while to come to market, with additional testing and research required to make it compatible for phone batteries.

We’re not far off from drastic changes in how we charge our devices. Just last week, Samsung announced the Galaxy Note 9 with a new S Pen that uses supercapacitor tech, to get near-instant full charges when the stylus is docked inside the phone. It’s exciting to think that near-instant charging is becoming reality.

Super fast charging like that would make my LAN parties go a lot smoother by keeping everyone charged and away from wall outlets, so I’m all for it. Until then, my LAN parties are just going to have setups with chargers of every type.

The existential loneliness of owning a USB-C phone

“Would you like to charge your phone?”
the Lyft driver asks
Wish I could say yes but it’s too herculean a task

before me, a string of cords splits into three
but none of them contain a USB-C

At the airport, at the party
a gathering at a friend’s house
Lightning fast appears but all else is denounced

“Hey Google, did I upgrade too soon?
am I the making of my own lampoon?


A minor chitchat, not trying to be a brat
but even the robot companion replies, “I can’t answer that”

The existential loneliness of a USB-C phone owner
Nary a pal with the rightful cord
and is dongle life really the future we want to head toward?

Technically standard but not yet the norm
The pace of adoption leaves me forlorn

Why the future of the power grid depends on giant batteries

Say “battery,” and most people think of the device that powers our phones, our laptops, and — maybe if they’re being ambitious — our electric vehicles. But it’s time to think bigger: at their core, batteries are simply a way to store energy, and, with some creativity, they’re capable of powering electric vehicles, houses, and entire cities.

There’s the Tesla batteries acting as backup for a wind farm in Australia. There’s PG&E building the world’s biggest battery in California to store electricity for its grid. And there’s the $3 billion project to turn the Hoover Dam into one big battery.

Being able to store energy is key, and there are plenty of ways to do it. The Verge explores the latest developments in energy storage, from those giant batteries to infinitely spinning flywheels to bottling gas in underground caverns. We’ll talk to Tesla, and explore the pros and cons of each method and what they mean for how we’ll power our lives in the future.