From smartphones to laptops, from electric cars to electronic cigarettes, lithium-ion batteries are powering a wide range of electronic products. However, with the potential of lithium being developed to the extreme, researchers are working hard to find the next breakthrough point.
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. Mike Zimmermann (Mike Zimmerman), founder and chief executive of Ionic Materials, said: "there is a smart phone in your pocket like kerosene in your pocket."
Zimmerman witnessed this burning effect at his company's 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 (Alessandro Volta) invented the battery in 1799 to solve the debate about frogs, every cell 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 (Stan Whittingham), worked at the Exxon plant in Linden, New Jersey, built an anode with aluminum to form "walls and floors in the apartment block" and used lithium as a 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 world's 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, John Goodenough, an American physicist 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, Goodnov's cathode appears in almost every handheld device on Earth, but he doesn't 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 J's 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.
Jean Bodichevski (Gene Berdichevsky) 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 charger 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. That's why airline safety videos now warn you not to try to adjust your seat if your phone falls into a mechanical device.
Every improvement of lithium-ion battery requires trade-offs. Increasing energy density reduces safety, and introducing fast charging may reduce the cycle life of the battery, which means the performance of the battery will decline more quickly. The potential of lithium ion is approaching its theoretical limit. Since Gould's breakthrough, researchers have been trying to find the next leap, including a systematic review of the four main components of the battery - cathode, anode, electrolyte and separator, and the use of more and more complex tools.
Claire Grey (Clare Grey), a student at the University of Oxford, has been studying the lithium 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 Gray's claims of recent breakthroughs, the group's 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, the material scientist, Liu Xuqing (Xuqing Liu), 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 iPhone X's battery is almost the same as that of SONY's 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 it's basically used in the thermodynamic capacity of batteries," Berdychevsky said. In 2011, he co founded Sila Nanotechnologies with former colleague of Tesla, Alex Jacobs (Alex Jacobs) and professor of materials science at Georgia Institute of Technology (Gleb Yushin). 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.