Do you have a low battery status? What if you don’t have to charge your phone again for another month? What if your electric car could travel 1000 miles on a single charge? And if your electric car charge in 10 minutes, and last for 1 million miles, with a new battery technology?
Current battery technology.
Today just about every electric car uses lithium-ion batteries. They are pretty good, but ultimately they are heavy. And have long charging times for the amount of energy they can store.
To add insult to injury, the energy density of decomposed organisms destructively drilled from the earth still achieve more than 100 times the energy density of the batteries used in most electric cars. 1 kilogram of gasoline contains about 48 megajoules of energy. lithium-ion battery packs only contain about 0.3 megajoules of energy per kilogram. What’s more, lithium batteries degrade with each charging cycle, gradually losing capacity over the battery’s lifetime. Researchers often compare batteries by the number of full cycles until the battery has only 80% of its original energy capacity remaining.
According to Elon Musk, battery modules are the main limiting factor in electric vehicle life. In 2019, he said that, “Tesla Model 3 drive unit can drive for 1 million miles”. But the battery only lasts for 300,000-500,000 miles or about 1,500 charge cycles.
Problems with lithium-ion battery technology.
Energy density and lifetime improvements to batteries appear to be the most crucial issues. There are environmental, geopolitical problems associated with current lithium-ion batteries. And they are pressing to solve to reach the battery of tomorrow.
China has over 80% of the world’s lithium deposits. And it leads to questions of international dependence on this monopoly of an element on which the world depends on technology to function.
Current technology also relies heavily on cobalt, an element mostly found in the Democratic Republic of Congo. The mining industry of the world’s largest producer is often made up of competing rebel militias that use child labor. Much is illegally exported and directly funds armed conflict in the region. Additionally, the camps often create conditions that drive deforestation and an array of human rights abuses.
To handle the predicted demand explosion for electric vehicles over the coming decades, we’ll need to create better batteries that are cheaper, longer-lasting, more durable, and more efficient. We must also address the issues of political and environmental sustainability to ensure batteries remain tenable in an increasingly electric future.
Tesla new 4860 tabless battery technology.
We have answers to many questions after Tesla’s long-awaited battery day took place on September 22nd. The Palo Alto automaker announced a larger, tabless 4680 battery cell. They did it with improved energy density, greater ease of manufacturing, and lower cost.
4680 battery cell
The king-sized cells make use of an improved design that eliminates the tabs normally found in Lithium-Ion batteries that transfer the cell’s energy to an external source. Instead, Tesla took the existing foils, laser powdered them. And they enabled dozens of connections into the active material through this shingled spiral. This more efficient cell design alleviates thermal issues, and simplifies the manufacturing process.
Tesla also introduced high-nickel cathodes that eliminate the need for cobalt.
And improved silicon battery chemistry in which they stabilize the surface with an elastic ion-conducting polymer coating. It allows for a higher percentage of cheap commodified silicon to be used in cell manufacture.
All together these changes create an expected 56% improvement in Tesla’s cost per kWh. And the new 4680 cells expect to achieve a 5 times increase in energy storage, a 16% increase in range, and a 6 times increase in power. Tesla hopes the improved cell design will allow them to achieve an eventual production target of 3 terawatt-hours per year by 2030. And help scale the world’s transition to ubiquitous long-distance electric vehicles.
New battery technologies
After Tesla’s recent battery day, the world’s attention is now more focused on batteries than ever before. But Tesla isn’t the only show in town. In the following article, we’re going to explore 5 exciting new battery technologies that could change the future.
Metal air batteries have been around for a while. You might find a little zinc air button cell in a hearing aid, for example. And scaled up aluminum and lithium-air chemistries are also promising for the automotive and aerospace industries. The potential for lightweight batteries with high-energy storage makes this battery technology promising.
lithium-air vs lithium-ion battery technology.
lithium-air batteries could have a maximum theoretical specific energy of 3,460 Wh/kg, almost 10 times more than lithium-ion. Realistic battery packs would probably be closer to 1000 Wh/kg. And this is still three to five times higher than lithium-ion batteries can achieve.
As usual, this technology is not without its drawbacks. Current electrodes of lithium-air batteries tend to clog with lithium salts after only a few tens of cycles. Most researchers are using porous forms of carbon to transmit air to the liquid electrolytes. Feeding pure oxygen to the batteries is one solution but is a potential safety hazard in the automotive environment. Researchers at the University of Illinois found that they could prevent this clogging by using Molybdenum Disulphide Nanoflakes to catalyze the formation of a thin coating of Lithium Peroxide (Li2O2) on the electrodes. Their test battery ran for 700 cycles, compared to just 11 cycles of an equivalent with uncoated electrodes. While this isn’t enough lifetime for a car, it’s a promising hint of things to come. More on nanotechnology later.
Use of lithium-air battery technology.
NASA researchers have also been investigating lithium-air batteries for use in aircraft. They believe that once their research cell is optimized, it should be looking at around 800-900 Wh/kg. Powerful enough to reach the high power requirements of takeoff. But they too are struggling with low battery life. For them, the solutions will boil down to improvements in the electrolyte. In an interview with Chemical and Engineering News, researchers commented, “From an organic chemistry perspective, the challenge of lithium-oxygen (Li-O2) is that you’re basically asking an electrolyte to face many of the harshest reactive oxygen species possible.” They are now investigating molten salt electrolytes, but hope to carry over the research into solid-state alternatives in the future to improve battery lifetime and cyclability.
This technology still has a long way to go before you take your next business trip is in an electric passenger jet, but the promise of such high specific energy will hold researchers’ interest for the foreseeable future, driven on by the promising advances made in recent years.
what is Nanotechnology?
Nanotechnology has been a buzzword for several decades. It is now finding applications in everything from nanoelectronics to biomedical engineering, body armor to extra-slippery clothing irons, and in Battery technology. Nanomaterials make use of particles and structures 1-100 nanometers in size, essentially one size up from the molecular scale. The magic is that they behave in unusual ways. Because this small size bridges the gap between that which operates under the rules of quantum physics and those of our familiar macro world.
The role of nanotechnology in the development of battery.
One of the challenges in battery design is the physical expansion of lithium electrodes as they charge. Researchers at Purdue University made use of antimony ‘nanochain’ electrodes last year to enable this material to replace graphite or carbon-metal composite electrodes. This extreme expansion can accommodate by structuring this metalloid element in this ‘nanochain’ net shape, within the electrode since it leaves a web of empty pores.
The battery appears to charge rapidly and showed no deterioration over the 100 charge cycles tested. Carbon nanostructures also show great promise. Graphene is one of the most exciting of these. Graphene is made up of a single atomic thickness sheet of graphite, and it turns out that this material has very interesting electrical properties, being a very thin semiconductor with high carrier mobility. Meaning that electrons are transmitted along with it rapidly in the presence of an electric field, as inside a battery.
It is also thermally conductive and has exceptional mechanical strength, about 200 times stronger than steel. Grabat, a Spanish nanotechnology company is pursuing graphene polymer cathodes with metallic lithium anodes, a highly potent combination if their electrolyte can adequately protect the metallic anode and prevent dendrite growth.
This New battery technology promises to be lighter and more robust than current technology while charging and discharging faster and with greater energy capacity. Samsung has patented a technology they call ‘graphene balls’. These are silicon oxide nanoparticles which are coated with graphene sheets that resemble popcorn. These are used as the cathode as well as being applied in a protective layer on the anode.
The researchers found increases in the volumetric density of a full cell of 27.6% compared to an uncoated equivalent and the experimental cell retains almost 80% capacity after 500 cycles. Additionally, they accelerated the charging and improved temperature control. NanoGraf, meanwhile, are using graphene sheets to produce carbon-silicon batteries to increase stored energy by 30%. Amprius go one stage further with their anodes of 100% silicon nanowire.
Usage of nanotechnology batteries
The maker claims that they can achieve 500 Wh/kg which is in the range suitable for enabling electric Aircraft, Airbus Space and Defence announced a partnership with the company last October. The silicon nanowires are attached to a thin foil by vapor deposition in a continuous. Roll-to-roll production process helping keep manufacturing costs down. The clever part is that these finger-like projections are porous on a micro and macro scale. It allows them to swell freely without significant expansion of the whole electrode. Just as trees swell with leaves in spring but the forest remains the same size.
Some internet sleuths concluded that Tesla acquired the company recently. Because Amprius recently moved their headquarters right next to a Tesla facility. But Elon Musk debunked these claims on Twitter. Saying, “But actually nothing. I surprised to hear they’re across the road. Adding silicon to carbon anode makes sense. We already do. The question is just what ratio of silicon to carbon & what shape? Silicon expands like crazy during discharge & comes apart, so cycle life is usually bad.”
Nanomaterial research is promising. The University of California Irvine have even produced electrodes good for 200,000 cycles using gold nanowires and manganese dioxide with a polymer gel electrolyte and many other research efforts are ongoing with other diverse materials.
One thing that seems to be sure though is that as soon as it’s possible to mass-produce suitable nanotechnology, we will be seeing this New battery technology in our batteries in some form and quite possibly in conjunction with silicon.
Lithium Sulphur batteries are one emerging new battery technology that can offer greatly improved energy densities compared to lithium-ion. The theoretical maximum specific energy of this chemistry is 2,567 Wh/kg compared to lithium ion’s 350 Wh/kg maximum. This is a huge improvement. A lithium Sulphur battery could be up to seven and a half times lighter than its current equivalent. Right now, lithium Sulphur batteries are nowhere near their theoretical limit. But the ALISE, a pan-European collaboration is working towards attaining a stable automotive battery of 500 Wh/kg based on this technology. In terms of economics, Sulphur is much cheaper than cobalt and manganese. It would replace and can be extracted as a by-product of fossil fuel refinement or mined from abundant natural deposits.
Lithium Sulphur vs lithium-ion battery technology.
Existing lithium-ion batteries are made up of an anode and cathode between which a liquid electrolyte allows dissolved lithium ions to travel. Lithium Sulphur batteries are constructed similarly, except that the active element in the cathode is Sulphur, while the anode remains lithium-based.
Researchers are facing a few challenges in bringing this new battery technology to market. Firstly, Sulphur is a poor conductor of electricity. Typically the Sulphur atoms are embedded within the matrix of carbon atoms in graphite, an excellent electrical conductor. This arrangement is vulnerable to a process known as shuttling. It causes batteries to drain when not in use. And also corroding metallic lithium anodes, reducing capacity as the battery is cycled. Next and most significantly, the electrodes physically swell up as lithium ions bond to them. This is more dramatic with lithium Sulphur than existing chemistries. The Sulphur cathode expanding and contracting by as much as 78% as the battery cycles or eight times more than cathodes typically used in lithium-ion batteries.
As might be expected from this kind of repeated strain, polymer or carbon-based supports and binders fragment and can disintegrate as the battery cycles, reducing capacity and performance. One approach to solving this is to bind the cathodes with different polymers and to reduce their thickness so that the absolute change in dimension is not so extreme.
Problems with lithium-based batteries
Many lithium-based batteries deal with dendritic growth. When this happened Thin fingers of the metal grows away from the surface. It eventually reaches across to the cathode. This creates a short circuit and rapid discharge. This is the same thermal runaway malfunction which has caused lithium-ion battery fires in the past. So research for coping with this effect can be carried over to lithium Sulphur technology, including exciting uses of graphene and other nanostructures to act as scaffolds for the deposition of lithium. Solid-state electrolytes could also offer solutions to these issues.
Lithium Sulphur batteries are not just an idea. Airbus Defense and Space flew a 350 Wh/kg battery made by Sion Energy back in 2014 powering their Zephyr High Altitude Pseudo-Satellite. Researchers at Monash University in Australia announced in 2020 that they anticipate having a product ready for commercialization in 2-4 years which could provide electric cars with a 621-mile range.
Usage of solid-state batteries
A common theme in emerging technologies so far has been researchers desire to develop solid state electrolytes. These would replace flammable organic liquids with stable, crystalline or glassy-state solids, or polymer-base. It is hoped that using these solid electrolytes would enable the use of metallic lithium electrodes to provide higher output voltages and allow for increased energy density. Additionally battery safety improves in vehicle crashes, and becomes more resistant to overheating and short circuiting, in part due to physical blocking of the dendritic growth of lithium and other electrode materials which currently plague lithium batteries.
Apart from its theoretical promise, we can be confident that we will see solid-state batteries powering us along the road in the near future. Because carmakers as diverse as Volkswagen, Toyota, BMW, and Hyundai have all been investing in the technology. Volkswagen, for example, put $300 million into QuantumScape, a Stanford University spin-off. QuantumScape has been holding its cards close to its vest as the website offers no information on their product, only a long list of new job openings, implying company expansion and confidence in their product. It is notable that they hold patents on sulphide-based lithium-ion technology and seem to be interested in thin, sintered ceramic films and lithium impregnated garnet.
Difficulties with solid-state battery technology.
One of the difficulties in solid-state electrolyte design is dealing with the expansion of electrodes. It is more difficult to manage in solid materials. A solid electrolyte must be sufficiently flexible to permit this, yet also tough enough to resist dendrite penetration. QuantumScape hold a patent for Composite Electrolytes to allow them to customize and adjust the physical properties of their electrolytes for such conflicting requirements.
Panasonic have also been looking into solid-state electrolytes. It is notable that Tesla partnered with Panasonic in their existing lithium-ion manufacturing capacity. But Toyota publicly announced their collaboration with Panasonic to develop next-generation solid-state batteries.
Samsung too are working on this new battery technology, and in May 2020 described their technology based on a silver and carbon anode, claiming this could give a generic electric car a 500 mile range and survive over 1000 charging cycles.
This is probably good news for your phone and laptop too given their current commercial interests. It may be just a matter of time before solid state electrolytes are in your pocket and in your car.
Dual Carbon vs lithium-ion battery technology.
This new battery technology has the ability to extract more power than from conventional lithium-ion, and their ability to charge 20 times faster, and these lithium-ion variants could be the future for electric vehicles. PJPEye, an offshoot of Japan Power Plus have developed this technology with the National Kyushu University in Fukuoka and are currently supplying their Cambrian batteries to an electric bicycle company, Maruishi Cycle.
Currently, these are single carbon electrode batteries, and details of their exact makeup are hard to find, but they are simultaneously working on a fully dual carbon battery with two carbon electrodes, eventually to be manufactured from natural, agriculturally grown products.
They anticipate achieving performance similar to graphene-based batteries. Although their Cambrian batteries have lower specific energy and lower energy density than lithium-ion – meaning that their batteries are both heavier and bulkier than their equivalents – they boast higher specific power.
Advantages over lithium-ion battery technology.
For the same mass of battery as a lithium ion-based alternative, it’s possible to extract the energy much faster, translating into faster vehicle accelerations. In addition to this, unlike lithium-ion, these carbon-based batteries are fully dischargeable .
The maker claims that this changes the equation for actual usable energy density, boasting a 40% improvement in range over lithium-ion batteries of the same capacity. Moreover, they say that the battery runs cool and does not require the heavy cooling systems of current electric vehicles. Their claim that a proof-of-concept battery degraded only 10% after 8000 cycles is very promising. They plan to gradually upscale from low volume applications, such as medical devices and satellites, towards mass-market aerospace and automotive customers with a battery made from carbonized cotton fibers rather than exotic, toxic metals. With fast charging and exceptionally low battery degradation over thousands of charging cycles. Maybe these will provide long term, sustainable solutions for commercial vehicles in the coming decades.