Energy

Tests show why QuantumScape solid-state battery has serious backing

Tests show why QuantumScape so...
QuantumScape's solid state battery (right) stores far more energy per weight and volume than regular lithium-ion cells (left), and has just passed a series of EV-related tests with flying colors
QuantumScape's solid state battery (right) stores far more energy per weight and volume than regular lithium-ion cells (left), and has just passed a series of EV-related tests with flying colors
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QuantumScape's solid state battery (right) stores far more energy per weight and volume than regular lithium-ion cells (left), and has just passed a series of EV-related tests with flying colors
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QuantumScape's solid state battery (right) stores far more energy per weight and volume than regular lithium-ion cells (left), and has just passed a series of EV-related tests with flying colors

California's QuantumScape has announced stunning performance figures for what may be the first commercially viable solid-state lithium-metal battery. It's claimed to add as much as 80 percent to the range of an electric car, and charge from 0-80 percent in just 15 minutes.

Using a solid electrolyte instead of the typical liquid solution, solid state batteries can store considerably more energy by weight and volume than today's lithium cells, but creating one that can stand up to the rigors of use in an electric vehicle – high charge and discharge rates, long lifespans, temperature and safety concerns – has proven difficult.

QuantumScape says it's cracked the problem with a new design using lithium-metal anodes that aren't formed during manufacturing, but that form around the current collector when the battery is charged. The solid-state separator is another key advance, using solid ceramic material that strongly resists the formation of dendrites – a common problem that can cause batteries to short out and sometimes catch fire when metal deposits build up on one electrode so much that they form spikes and pierce the separator.

So let's see the numbers. Energy density is reportedly excellent. In volumetric terms, the new battery can store 1 kWh/liter, about four times what the current Tesla Model 3 battery stores. By weight, it offers somewhere between 380-500 Wh/kg, compared to around 260 Wh/kg for the current Tesla packs – although renowned optimist Elon Musk reckons he can get 400 Wh/kg out of Tesla cells within three to four years in serious volume.

The QuantumScape battery charges at crazy-high rates, enabling 0-80 percent charging in 15 minutes assuming a big enough electron pipe is available. The life cycle of a single-layer pouch cell constantly charging and discharging at 1C (full charge in 1 hour, full discharge in 1 hour) in a rather warm 30 °C (86 °F) was also very strong, retaining more than 80 percent of its capacity after 800 cycles. This would represent about 240,000 miles (386,000 km) traveled in an EV, and a strong step forward, says the company, from the lifespans demonstrated by other solid-state contenders.

Cold temperature performance is also noteworthy; significant capacity is available as low as -30 °C (-22 °F), making life a lot easier for those living in colder climes. In safety terms, the company says its ceramic-based separator is non-combustible and keeps the anode and cathode safely isolated at temperatures much higher than today's lithium-ion cells can handle.

“The hardest part about making a working solid-state battery is the need to simultaneously meet the requirements of high energy density, fast charge, long cycle life, and wide temperature-range operation. This data shows QuantumScape’s cells meet all of these requirements, something that has never before been reported. If QuantumScape can get this technology into mass production, it holds the potential to transform the industry,” says Dr. Stan Whittingham, co-inventor of the lithium-ion battery and winner of the 2019 Nobel prize in chemistry.

“These results blow away what was previously thought to be possible in a solid-state battery,” adds Venkat Viswanathan, battery expert and professor of materials science at Carnegie-Mellon University. “Supporting high enough current density to enable fast charge without forming dendrites has long been a holy grail of the industry. This data shows the capability to charge to 80 percent capacity in 15 minutes, corresponding to an astonishingly high rate of lithium deposition of up to a micron per minute.”

High praise, indeed. And QuantumScape has some serious backing behind it, including a commitment of some US$300 million from its largest shareholder and partner, the Volkswagen group, among others including Continental and Bill Gates. So it should have every conceivable resource at its disposal to commercialize this battery at epic scale for some future generation of Volkswagen EVs.

Check out a video below.

What are Solid-State Lithium-Metal Batteries?

Source: QuantumScape

11 comments
11 comments
Nixter
We need these batteries like yesterday, there are laboratories all over the world working on solid state batteries it’s good to see some practical breakthroughs being made in the field. Of course we shouldn’t get too excited just yet, until these are being manufactured and used in cars, laptops, and flying electric taxis, there is probably going to be quite a few years before we see this tech in common usage.
michael_dowling
I will get really excited if Elon Musk announces he has invested in QuantumScape. It is encouraging to read that VW has a stake in it. Musk has said that one of his goals was to see the world turn away from ICE technology, and if other manufacturers get a piece of the action,he is okay with that.
paul314
The fast charging rate is really cool, but I want to see what happens to lifetime at more realistic temperatures. The outside of many batteries during fast charge or discharge is hot to the touch, so maybe 40-50 C instead?

But every bit helps. (And somebody has to figure out how to do fast charge on a bunch of vehicles without overloading the local electrical grid.)
Catweazle
All very interesting, but still does not address the major problem of energy density by comparison with fossil fuels.

It will take improvements of orders of magnitude, not incremental improvements, before battery storage will be capable of replacing fossil fuels to an major extent, as this graph makes clear.

https://upload.wikimedia.org/wikipedia/commons/c/c6/Energy_density.svg
SteveMc
In reply to Catweazles' comment: The battery density and performance is only a part (1/3rd?) of the equation. Electrical Motor performance, aerodynamics, weight and also the chargers will also improve as we take this journey towards fossil fuel free vehicles.The other important factor is people need to improve their driving habits/skills. It's no use saying "Yeah but I love my gas guzzler and won't give it up!" However, the writing is on the wall and this will have to happen, happy or not.
Scott Mckinsey
It's easy to get jaded reading about the 'latest' battery breakthrough. What is the downside? How about the amount of lithium available. Currently little or no lithium is recyclable and even if it was there isn't an infinite amount available. Current known reserves are woefully inadequate also.
paul314
@SteveMc the comparisons between battery energy density and oil/gasoline/etc energy density have always been wrongheaded, because they're basically apple trees to oranges. One of those things is the actual energy carrier, the other is the container for the energy carrier. As you point out, at the very least you have to compare the systems including motors, transmission, fuel system, exhaust system etc. (An internal combustion fan would similarly cry foul if someone compared the mass of a gallon of gasoline to the mass of an energy-equivalent number of electrons.)
Eddy
Will they be available in 100ah size + for the 4WD and camping use and not just for electric cars.
michael_dowling
Catweazle: Energy density per se is not the only consideration. ICE has plenty of energy density,but can only deliver ~ 15% of it to the wheels. EV batteries have much lower energy density,but can deliver 95% or more to the wheels. The reborn Aptera is a prime example of what you can do with batteries and an efficient design. The car has a drag co-efficient of 0.12, if memory serves,and with the largest battery pack,can travel ~ 1000 miles on a charge.
Emma Chack
OH screw you're car..We need phones,laptops,hand held and wearable electronics first, that's were It's needed more I'm sick of battery tech lagging so far behind for decades It's not even funny.
NOn-rechargeble battery's need to go the way of the corner payphone and die.
Sorry, just tired of seeing really promising things "Only 2-5 years away" and then POOF! Nothing