Batteries and Supercapacitors — Future of Energy Storage?
The global production of electric vehicles is likely to increase at an astonishing pace. That means automakers need a lot more batteries, and all that demand could mean a bottleneck. NPR’s Camila Domonoske reports.
LOGAN GOLDIE-SCOT: We expect lithium-ion battery demand to increase at least tenfold over the next decade.
THE Mobira Senator, launched in 1982 by Nokia, was the grand-daddy of today’s mobile phones. It consisted of a small handset connected to a brick-like battery pack, with a hefty handle on top — a vital feature, since the whole thing weighed 9.8kg. Today, a typical mobile phone is a hundredth of this (ie, 100 grams or less) and can be tucked discreetly into a shirt pocket. This 99% weight reduction has been achieved largely through advances in battery technology. Above all, it is down to one particular breakthrough: the advent of the lithium-ion rechargeable battery.
The entire arc of human history has been defined by how we harness and capture energy. Initially starting with early humans leveraging fire and then later coal and petroleum fuel sources for our energy needs. And really the great opportunity going forward is this idea of generating tremendous amount of renewable energy sources, store than energy and then use that to power our lives.
Lithium-ion batteries were first introduced commercially in the year 1991 by Sony. Ever since then, there have been extensive improvements and countless research to enhance the performance of these batteries.
Advances in battery design and expertise, has made the modern technology possible, but its not enough. We need more better, cheaper and more energy dense batteries if we are going to make electric cars omnipresent while doing our bit to save the planet.
Multiple companies these days are on the verge of battery breakthroughs that could change the world and the over all presence of automotive industries. The battery industry has been kind of stuck making batteries one way for like 50+ years and we think its just time for that to change.
A battery looks like a black box quite literally sometimes but inside it is a very complex mixture of chemicals.
There are four components, two electrodes cathode and anode, there is a separator and a liquid electrolyte typically. The electrolytes job is to shuttle ions between the two electrodes. That is basically what charges the battery and that is what allows the battery to be then discharged and produce power. Among the everyday technologies, batteries are perhaps the oldest because batteries were invented even before electricity was invented which is to say there was no way to generate electricity until someone made a battery and that was back in 1799 by an Italian scientist named Volta. What he created was called a voltaic pile, it was not even called a battery back then. It was called a pile, because in this case it was a pile of two different metals copper and zinc separated by typically a piece of cardboard that was dipped in vinegar.
Batteries have come a long way since the voltaic pile, but they are still made up of the four basic components, anode, cathode, separator, and an electrolyte. The current state of the lithium-ion battery is small, light and relatively powerful making everything from mobile devices to electric cars, possible.
But in order to make decarbonization a reality, batteries need to get much better.
Among the different things about batteries that still needs to be improved, it is not just the amount of energy they can store, but they also must do it safely. Batteries also need to be charged more quickly, and finally batteries still are not cheap enough. They probably need to be half the price to be able to compete with the gasoline powered engine.
To accomplish that, a number of companies are trying to go inside the black box, and tinkering with those four basic components hoping to jumpstart the next generation of batteries.
“Batteries have a long history of pretty slow improvement on the order of 4–5% a year” Harold Rust, Enovix.
Harold Rust’s company Enovix, based in south of San Francisco is making one seemingly small tweak in the lithium-ion battery.
Replacing the anode typically made of carbon with silicon. Major advantage of silicon is that it has three times the energy density of carbon which it replaces so that allows you to pack more stuff in your battery and drive up energy density. Silicon being a great anode, suffers from a bunch of problems and the biggest of which is the fact that it expands 300%. When you are charging a cell, the silicon tends to expand and when you are discharging, it compresses or contracts.
A silicon anode battery could store about 50% more energy than what is currently on the market which could mean we might see lighter electronics with longer battery life soon.
QuantumScape in San Jose is working on an even more ambitious battery design. QuantumScape is a leader in the development of next generation solid-state lithium-metal batteries for use in electric vehicles. The company’s mission is to revolutionize energy storage to enable a sustainable future.
We started with the mission of trying to narrow the gap between combustion engine-based vehicles and EVs and we recognized that the key there was to build a better battery we could usher in a new era of transportation. — Jagdeep Singh, CEO QuantumScape
15mins charge time, better life performance, and even lower costs.
It turns out all those problems can be addressed if you just switch from a carbon or carbon-silicon anode to a lithium metal anode.
Jagdeep Singh, CEO of QuantumScape, commented: “Volkswagen is the world’s largest automotive manufacturer and leads the industry in its commitment to electrification of its fleet. We are thrilled to be chosen by Volkswagen to power this transition. We think the higher range, faster charge times, and inherent safety of QuantumScape’s solid-state technology will be a key enabler for the next generation of electrified powertrains.”
A commercially viable solid-state lithium-metal battery is an advancement that the battery industry has pursued for decades, as it holds the promise of a step function increase in energy density over conventional lithium-ion batteries, enabling electric vehicles with a driving range comparable to combustion engine-based vehicles. QuantumScape’s solid-state battery is designed to enable up to 80% longer range compared to today’s lithium-ion batteries. Previous attempts to create a solid-state separator capable of working with lithium metal at high rates of power generally required compromising other aspects of the cell (cycle life, operating temperature, safety, cathode loading, or excess lithium in the anode).
QuantumScape’s newly-released results, based on testing of single layer battery cells, show its solid-state separators are capable of working at very high rates of power, enabling a 15-minute charge to 80% capacity, faster than either conventional battery or alternative solid-state approaches are capable of delivering. In addition, the data shows QuantumScape battery technology is capable of lasting hundreds of thousands of miles, and is designed to operate at a wide range of temperatures, including results that show operation at -30 degrees Celsius.
“The hardest part about making a working solid-state battery is the need to simultaneously meet the requirements of high energy density (1,000 Wh/L), fast charge (i.e., high current density), long cycle life (greater than 800 cycles), 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,” said Dr. Stan Whittingham, co-inventor of the lithium-ion battery and winner of the 2019 Nobel prize in chemistry.
Researchers recently and quite accidentally discovered something that could change the whole electric car ballgame. If their predictions are accurate, then we can one day live in a world where cars can be fully charged in minutes instead of hours, and their power shortage units would last decades instead of years.
A monumental leap forward in capacitor technology. Many of the current drawbacks of electric cars stem from how batteries work. Batteries rely on chemical reactions, which means for a lithium-ion battery to release energy, you must wait for the lithium to shuffle through an electrolyte and when you want to store energy you have to wait for the lithium to shuffle back.
Lithium-ion batteries also degrade and replacing one in an electric car would be enormously expensive. In contrast capacitors store static electricity, like what builds up on a balloon as you rub it on your hair.
Capacitors can be as simple as two metal plates separated by air. When a current is applied to the plates, a positive charge builds up on one plate and a negative charge builds up on the other. No electrolytes, no shuffling ions, just electrons on a plate waiting to pounce. As a result, capacitors can be fully charged almost instantly and since they can also deliver energy quickly that means capacitors can provide more power than batteries. They are much more durable than lithium-ion batteries too, lasting through tons of charge and discharge cycles with little degradation. There is one little obstacles to this, they just can’t hold very much energy. There are tricks to squeeze more charge onto the plates, like increasing their surface area and reducing the distance between them by swapping out the air with a thin insulator.
Supercapacitors today still hold just 10 watt-hours per kilogram, about 5% of the energy density of a lithium-ion battery of the same weight. You would need a capacitor the size of a bus to get any real use out of it.
For now, regular old chemical batteries are still the best fit for electric cars, but if there is a breakthrough that researchers are currently focused on, batteries could be on their way out in the next decade.