If you read this article on a smartphone, it means you are holding a bomb. Under a protective screen, lithium (a very volatile metal, once touched with water) is being decomposed and rebuilt in a powerful chemical reaction that provides an indispensable impetus to the modern world.
Lithium is being used in mobile phones, tablets, laptops and smart watches, and in our electronic cigarettes and electric cars. It is light and soft and belongs to energy intensive substances, making it the source of the perfect power of portable electronic products. However, as consumption technology becomes more and more powerful, lithium-ion battery technology is still difficult to keep pace with. Now, just as the world is addicting to lithium, scientists are scrambling to reinvent batteries that provide power to the world.
A huge light screen, faster processing speed, fast data connection and light design fashion, which means that many smartphones are hard to support all day. Sometimes, the mobile phone users even have to recharge it many times. After two years of use, the battery life of many devices will be sharply shortened and they will have to be thrown into the garbage dump. The great advantage of lithium is its greatest weakness. It is unstable and may explode. The power of lithium ion laptop batteries is almost the same as grenades. IonicMaterials founder and chief executive Mike Zimmermann (MikeZimmerman) said: there is a smart phone in the pocket like the kerosene in the pocket.
Zimmerman witnessed this burning effect at his companys research laboratory in Woburn, Massachusetts. In one experiment, a machine drives a nail through a battery pack, and the battery pack expands quickly, like a popcorn in a microwave oven, and then sends out bright flashes. Battery research over the past 50 years has always been a tightrope between performance and safety, that is, extruding as much energy as possible without pushing lithium to extremes.
We are doing this right now. It is predicted that by 2022, the global battery market will reach US $25 billion. However, consumers believe that battery life is the most concerned function of smart phones in one after another investigation. With the popularity of 5G networks with higher energy consumption in the next ten years, the problem will only become more and more serious. And for those who can solve problems, they will get huge rewards.
Ionic Materials is just one of dozens of Companies in an epic race to fundamentally rethink the battery problem. However, the competition was beset by false beginnings, painful lawsuits and failed start-ups. But after ten years of slow development, hope is still there. Scientists from start-ups, universities and well-funded national laboratories around the world are using sophisticated tools to find new materials. They seem to be going to substantially increase the energy density and endurance of smartphones and create more environmentally friendly and safer devices that will be charged in a few seconds and will be used throughout the day.
The battery generates electricity by decomposing chemical substances. Since the Italy physicist Alessandro Volta (AlessandroVolta) invented the battery in 1799 to solve the debate about frogs, every battery has the same key component: two metal electrodes - negative anode and positive cathode, separated by substances called electrolytes. When the battery is connected to the circuit, the metal atoms in the anode react with each other. They lose an electron, become positively charged ions, and are attracted to the cathode by electrolytes. At the same time, electrons (also negatively charged) will flow to the cathode. But it does not pass through electrolytes, but is transmitted through the circuit outside the battery, supplying power to the equipment connected to it.
The metal atoms on the anode will eventually run out, which means the battery will run out of electricity. But in rechargeable batteries, this process can be reversed by charging, forcing ions and electrons back to their original positions, ready to start the cycle again. The electrodes made of pure metals cannot withstand the pressure of the atoms to go in and out without collapse, so the rechargeable battery must use composite materials to keep the anode and cathode shape through repeated charging cycles. This structure can be compared to apartment buildings, including rooms for reactive elements. The performance of rechargeable batteries depends largely on how fast you can get in and out of these rooms without causing buildings to collapse.
In 1977, the young British scientist, Stan Whittingham (StanWhittingham), worked at the Exxon plant in Linden, New Jersey. He built an anode with aluminum to form walls and floors in the apartment block and used lithium as an active material. When he recharges the battery, lithium ions move from the cathode to the anode and precipitate in the gap between aluminum atoms. When discharging, they move in another direction and return to the cathode side by electrolytes.
Whittingham invented the worlds first rechargeable lithium battery, a coin-sized battery that powers a solar watch. But when he tries to increase the voltage (to get more ions in or out) or try to make bigger batteries, they continue to burn. In 1980, American physicist John Goodnov (JohnGoodenough), who worked at University of Oxford, made a breakthrough. Goodnov was a Christian who served as an Army meteorologist during World War II and an expert on metal oxides. He doubted that there must be some kind of material that could provide a stronger cage for lithium than the aluminum compounds used by whiting ham.
Goodnow J instructing two postdoctoral researchers systematically groped in the periodic table, compared lithium with different metal oxides to see how much lithium could be pumped out of them before they collapsed. In the end, they identified a mixture of lithium and cobalt, which is a bluish gray metal in Central Africa. Lithium cobalt oxide can withstand half of the lithium being pulled out. When it is used as cathode, it represents a big step forward in battery technology. Cobalt is a lighter, cheaper material, suitable for both small and large equipment, and much better than other materials on the market.
Today, Goodnovs cathode appears in almost every handheld device on Earth, but he doesnt make a penny out of it. University of Oxford refused to apply for a patent, and he himself gave up the right. But it changed what could happen. In 1991, after 10 years of repair, SONY combined Goodnow Js lithium cobalt oxide cathode with the carbon anode to try to improve the battery life of its new CCD-TR1 camera. This is the first rechargeable lithium ion battery for consumer products, which has changed the whole world.
Photo: the production line of the Candy plant in Jinhua, Zhejiang, China, has a birds eye view of countless electric cars.
Jean Bodichevski (GeneBerdichevsky) was once the seventh employee of Tesla. When the electric car company was founded in 2003, the steady increase in battery energy density had been going on for a decade, by about 7% a year. But before and after 2005, Bo Dichev J Ki found that the performance of lithium ion batteries began to stabilize. In the past seven or eight years, scientists have to do their best to win even 0.5% of the battery performance.
Progress at that time mainly came from improvements in engineering and manufacturing. Bo Dichev J Ki said: after 27 years of modern chemical reactions, they are constantly being refined. Purer materials, battery manufacturers have been able to load more active materials into the same space by making each layer thinner. Bo Dichev J Ki called it sucking the air out of the jar. But it also has its own risk. Modern batteries are made up of alternating layers of extremely thin cathode, electrolyte and anode materials, closely combined with copper and aluminum charge collectors to bring electrons out of the battery and send them to where they are needed.
In many high-end batteries, the plastic diaphragm is located between the cathode and the anode to prevent their contact and short circuit, which is only 6 microns thick (about 1/10 of human hair thickness), which makes them vulnerable to extrusion damage. Thats why airline safety videos now warn you not to try to adjust your seat if your phone falls into a mechanical device.
Claire Grey (ClareGrey), a student at the University of Oxford, has been studying the lithium - air battery, which uses oxygen in the air to act as another electrode. In theory, these batteries provide a huge energy density, but to recharge them reliably and last for more than a few dozen cycles is difficult enough in the laboratory, not to mention in the dirty and unpredictable air of the real world.
Despite Grays claims of recent breakthroughs, the groups attention has shifted to lithium-sulfur batteries because of the problems. It provides a cheaper and more powerful substitute for lithium ions, but scientists are always trying to stop the dendrites formed on the cathode (cathode) and the sulfur on the anode to dissolve because of repeated charging. Sony claims to have solved the problem and hopes to bring consumer electronics with lithium-sulfur batteries to market by 2020.
At the University of Manchester, material scientist Liu Xuqing (XuqingLiu) is one of those who try to squeeze more energy out of the carbon anode, combining a two-dimensional material similar to graphene in order to expand the surface area and increase the number of lithium atoms. Liu Xuqing compares it to the number of pages added to a book. The University also invested in the construction of dry laboratories, which would enable researchers to exchange different components safely and easily to test the combination of different electrodes and electrolytes.
It is unbelievable that even Goodnow J himself is studying this problem. Last year, he published a paper at the age of 94, describing a battery that is three times the capacity of the existing lithium ion battery. This has been widely questioned. A researcher said, if anyone else from Gould, published this article, I might have to curse.
But despite the thousands of publications, billions of dollars in funding, dozens of start-ups and funding support, the basic chemical functions of most of our consumer electronics have hardly changed since 1991. There is no substitute for lithium cobalt oxide and carbon in terms of cost, performance, and portability of consumer electronics. The principle of iPhoneXs battery is almost the same as that of SONYs first portable camera.
So in 2008, Bo Dichev J Ki left Tesla and began to focus on new battery chemistry. He is particularly interested in finding alternatives to graphite anodes, which he believes are the biggest obstacles to making better batteries. Graphite has been used for 67 years, and its basically used in the thermodynamic capacity of batteries, Berdychevsky said. In 2011, he co founded SilaNanotechnologies with Alex Jacobs, a former colleague of Tesla, Alex Jacobs (AlexJacobs) and Gleb Usin, a professor of materials at the Georgia Institute of Technology. They have an open layout in the Bay Area Office in Alameda, a conference room named after the yatali game, and an industrial laboratory full of furnace and gas pipes.
After investigating all possible solutions, the three of them theoretically identified silicon as the most promising material. They just need technology to play a role. Many people tried before them, but they all failed. However, Bo Dichev J Ki and his colleagues are optimistic about their success. A silicon atom can attach four lithium ions, which means a silicon anode can store 10 times as much lithium as a graphite anode of similar weight. This potential means that the American National Institute is full of interest in silicon anode materials, as is the same for start-ups supported by Amprius, Enovix and Envia.
When lithium ions are attached to the anode when the battery is charged, it will slightly expand and then shrink again when used. During repeated charging cycles, the expansion and contraction destroy the solid electrolyte interface layer, which is a protective substance that forms patches on the anode surface. This damage can cause side effects and consume part of the lithium in the battery. Bo Dichev J Ki said, its trapped in useless garbage.
Over time, this is the main reason why smart phones start to lose energy quickly. The graphite anode expands and shrinks by about 7%, so it can complete about 1000 charging and discharging cycles before the performance starts to decline sharply. This is equivalent to a smartphone lasting two years and charging every day. But because silicon particles can absorb so much lithium, they expand much more when charging (up to 400%). Most silicon anodes break after several charging cycles. Over the past 5 years in the laboratory, SilaNanotechnologies has created a nanocomposite to solve the problem of expansion.
Bo Dichev J Ki explained that if the graphite anode was a apartment area, all the rooms were the same size, and they were tightly packed together. After 30 thousand iterations (different columns and room combinations), they formed an anode, where each layer had enough space to expand the silicon atoms when they were getting lithium. He said, we are trapped inside the building. This solves the expansion problem while maintaining the external dimension and shape of the anode.
Bo Dichev J Ki said that the first generation of materials that SilaNanotechnologies will provide to manufacturers next year will increase the energy density by 20%, and eventually increase the energy level by 40%, as well as to improve security. He said: silicon can keep you away from the edge. You can leave 1% or 2% space to really increase your safety. Most importantly, it can also be directly converted into existing designs. As battery manufacturers in Asia are scrambling to increase factory capacity and prepare for the era of electric cars, Bo Dichev J Ki believes that any products that are incompatible with current production processes may be excluded. If there is no alternative to lithium ion, it will have a huge user base by the time it comes on the market, he said.
Photo: The man works on a salt beach in Uyuni, Bolivia, a 4,000-square-mile remote area with the worlds largest lithium reserves
When the battery is full of electricity and discharge, lithium ions dance between the two electrodes, sometimes they are hard to return. On the contrary, especially when the batteries are charged too quickly, they gather outside the electrodes and gradually form dendritic branches, like stalactites at the top of the cave. Eventually, these looks like the frosted dendrites on the window glass that can be extended through the electrolyte through the diaphragm, and a short circuit can be generated by touching the opposite electrode.
As the distance between layers becomes closer, the risk will increase and the possibility of error will increase. As Samsung discovered last year, mistakes can be damaging and costly. Tiny manufacturing defects have led to internal short circuit in GalaxyNote7 cell phone batteries. On some devices, the anodes and cathodes eventually came into contact with each other, a disastrous recall that is estimated to have cost Samsung 3.4 billion euros. When this happens, the battery becomes very hot, and the liquid electrolyte can escape, eventually causing fires and explosions, explains IonicMaterialss Zimmerman.
Because this situation is very dangerous, in fact, there are not so many lithium batteries in lithium ion batteries, only about two percent. But if there is a way to safely release pure lithium from metal cobalt oxide cages, as whence Hamm tried in 1970s, it could increase the energy density of ten times. This is known as the Holy Grail of battery research, and Zimmerman may have found it.
He thinks electrolytes are actually the biggest obstacle to increase the energy density of batteries. People have gradually no longer used substances immersed in liquid electrolytes, but using gels and polymers, but they are usually flammable and are not helpful in preventing rapid thermal escape. Zimmerman himself admitted that he was not a battery control. He majored in materials science, especially polymers, and he taught at Bell Laboratories and Tufts University for 14 years before starting a business.
In early twenty-first Century, Zimmerman began to interest in rechargeable batteries. At that time, some people were trying to turn from liquid electrolyte to solid electrolyte. Senior energy storage scientist Donald Highgate (DonaldHighgate) explained: in principle, because the solid electrolyte battery is safer, you can make it work harder. With the same application, you can use smaller batteries. But they are mostly ceramic or glass products, so they are brittle and difficult to mass produce.
Plastics have been used in batteries for isolators, which are in the middle of electrolytes to prevent electrodes from touching. Zimmerman believes that if he can find the right material, he can discard liquid electrolytes and separators, instead of a layer of solid plastic that can be fireproof, and also prevent the growth of dendrites between two layers. Through Ionic Materials, Zimmerman created a polymer that mimicked the way electrons travel through metals with a completely new conduction mechanism. This is the first solid polymer that can conduct lithium ion at room temperature. Materials are flexible, low cost and stand up to all kinds of tests.
In one experiment, they sent the raw material to a ballistics laboratory, where it was commonly used to test a bullet-proof vest and fire it with a 9mm bullet. Two wires connect the battery (flat silver bag) to the Samsung tablet computer, the latter being carefully removed. After the bullet struck, the battery exploded like a volcano. In slow motion, plastic and metal can be seen from the crater, just like lava. But there was no explosion inside the battery, no explosion or fire. Every collision, the equipment remains open. Weve always believed that polymers make it safer, and weve never expected batteries to continue to work, Zimmerman said.
According to Zimmerman, the polymer will drive the development of lithium metals and accelerate the adoption of new battery chemicals, such as lithium-sulfur or lithium-air. But the long-term future is probably not just lithium. Liu Xuqing, a researcher at the University of Manchester, said: This improvement can not match the speed of equipment performance improvement. We need a revolution.
In Oxford countys huge Havel science and Innovation Park, where John Goodnov (JohnGoodenough) signed an agreement to renounce his major breakthrough in the field of lithium ion, Stephen Waller (StephenVoller) holds a carbon fiber similar to the size and shape of the drink cup. Waller is an amiable City fan who is nearly 50 years old. Prior to joining the first browser brand Netscape (Netscape) company, he worked as a software engineer in IBM. Waller became increasingly frustrated with the laptop battery life limit after the company was acquired by AOL and decided to take steps.
Wallers first idea was to use hydrogen fuel cells to extend battery cruising time, but its volatility proved to be an insurmountable challenge for portable electronics. It is quite difficult to get hydrogen through airport security, he said. Then, through acquaintances at Oxford, Waller heard about some exciting research, including ultrafast charging materials that behave more like supercapacitors. When batteries store energy chemically, supercapacitors can place it in an electric field, just like a balloon collects static electricity.
The problem with supercapacitors is that they dont store as much energy as batteries, and the electricity leaks out quickly. If you dont use it very often, the discharge of lithium ion battery will last for 2 weeks, while the super capacitor can only be kept for several hours. Many in the industry believe that combining supercapacitors with batteries could benefit smartphones and other power-hungry consumer technology products. Highgate says supercapacitors can be used to make hybrid phones that can be full of electricity in one or two minutes, and can be used as a spare lithium ion battery. If you can charge very quickly, you can put it on the coil and charge it while you stir the coffee, he said.
Waller thinks he can do better. In 2013, he founded ZapGo, which is developing carbon based batteries that charge as fast as supercapacitors, but the charge time is similar to that of lithium ion batteries. By November 2017, the companys staff had increased to 22, working at Javiers Rutherford Appleton laboratory and Sherlocks office in North Carolina, respectively. Its first consumer battery will be used on third party products launched at the end of this year, including the booster starting device for cars, and electric scooters that shorten the charging time from 8 hours to 5 minutes.
The carbon fiber in Wallers hand is a battery, which uses solid electrolytes and does not catch fire. The two electrode is made of thin aluminum and covered with nanostructured carbon to increase the surface area. Waller said, you want it to look like Himalaya Range. Though under the microscope, it is more like the outline of the city skyline. The key to ZapGo technology is to improve efficiency and reduce leakage, mainly by ensuring that the electrolyte is seamless with the carbon skyline above, like nylon clasp.
The biggest advantage of carbon based batteries is longevity. Because ZapGos battery storage is more like a balloon than a traditional battery. As Waller puts it, No chemical reaction, he claims the new battery can last 100,000 discharge cycles, 100 times as long as the lithium-ion battery. Even if you charge your cell phone every day, you can use it for 30 years. The current third generation of ZapGo batteries are not yet strong enough to run smartphones, but because the materials used do not provide an obstacle to increasing the voltage, Waller expects the battery to be put into use in 2022, either before and after the iPhone15.
This needs to change the charging infrastructure. Many of the explosions were blamed on inexpensive third-party chargers that didnt have the electronic equipment needed to stop the explosion. For ZapGo batteries, or any system based on supercapacitors, you need a charger to do the opposite - absorb and store energy from the grid and send it to your cell phone in a short time. In the lab, Wallers team has built laptop-sized power supplies, but theyre trying to make them smaller and more efficient.
Compared with the existing technology, carbon based energy storage technology has another main advantage. It can actually be used as external structure of mobile phones. Instead of designing batteries that fit current mobile phone designs, Waller is preparing for the future of flexible screens and foldable devices. In the 5G network, all our data come from the cloud, and battery life becomes even more important.
Waller walked along the narrow corridor of his office and walked through the sun in the afternoon, through the shadow of DiamondLightSource, a huge ring building that looked like a spaceship landing in the countryside of Oxford county. Internally, researchers are using an accelerated beam to study potential battery materials at microscale, explore why lithium - sulfur batteries fail, and find alternative materials to obtain anode and cathode, which have been puzzling the field for nearly 30 years. Waller waved his smartphone in the air and lamented the defects of the lithium ion battery, which prompted him and hundreds of other people to join the high risk competition to reinvent these excellent but defective batteries. We all have to make strategies to deal with this, whether its a back - up battery or two mobile phones, he said. Its crazy. It shouldnt be that way. (small) source of this article: NetEase science and technology report editor: Wang Fengzhi _NT2541
Waller walked along the narrow corridor of his office and walked through the sun in the afternoon, through the shadow of DiamondLightSource, a huge ring building that looked like a spaceship landing in the countryside of Oxford county. Internally, researchers are using an accelerated beam to study potential battery materials at microscale, explore why lithium - sulfur batteries fail, and find alternative materials to obtain anode and cathode, which have been puzzling the field for nearly 30 years.
Waller waved his smartphone in the air and lamented the defects of the lithium ion battery, which prompted him and hundreds of other people to join the high risk competition to reinvent these excellent but defective batteries. We all have to make strategies to deal with this, whether its a back - up battery or two mobile phones, he said. Its crazy. It shouldnt be that way. (small)