What has changed from battery to lithium battery?

Battery pioneer Whitingham said: "We only know a little fur." As the world makes every effort to get rid of its dependence on fossil fuels, batteries are likely to play an increasingly important role in our daily lives, with lithium batteries even worse.

Can the battery compete with the storage capacity of gasoline in the future?

Three years ago, science journalist Farhad Manjoo wrote an article to the American online magazine saying that "a better battery will save the world," but the subtitle "retorted" the headline saying "too bad." It is impossible to do it." Although the automotive sector had just launched Tesla S, Nissan LEAF, Chevrolet Volt, and released a large number of new hybrid and pure electric vehicles, from box economy cars to two luxury hybrid Porsche.

The problems that Manoyo and others foresee are multifaceted: (1) car batteries are very expensive; (2) “energy density” (the amount of energy per unit weight) seems to be far worse than gasoline; (3) there may be Danger - The emerging key material of the battery, lithium itself, is unstable and turns into a powder in the air. One problem is that moisture can explode. Another problem is that the material is "isolated" and there is a possibility of "hot breakdown" - rapid heating until it catches fire. Therefore, it is important that lithium be kept cool and dry.

But the last warning is precisely why lithium is an attractive battery material: Its dangerous energy is a huge advantage. Therefore, there is a silent lithium "sprint" in battery technology that has been and continues to improve. In recent years, due to the advancement of batteries, fossil fuel vehicles have become an "aesthetic" choice, not a necessity for the economy. Our urban grid will become more complex, more predictable, reliable and economical.

Battery shock

The car battery has shifted from lead acid to lithium battery, nickel-cadmium flashlight to handheld lithium ion design, and the battery has become more efficient. Without a lithium-ion battery, there will almost certainly be no "mobile phone society". But approaching large equipment such as vehicles and power stations, where we can save our energy-consuming lives, there are plenty of winners such as the A123 system and its sponsors, Fiskar Karma, Mori Energy, Avestor, and Envia, which once powered the GM team, all lost millions and barely fled the starting gate.

If someone understands the challenges of the battery revolution, it is this man who opened the battle for the invention of lithium-ion batteries by Exxon in the late 1970s. It is M. Stanley Whittingham, now a professor of chemistry at Bingham University in northern New York State, who predicted that “every car will be a hybrid or an electric car in 10 years.”

He believes there are many reasons to be optimistic. For example, a lot of resources are being put into the technical challenges of making better batteries, from small start-up small computer companies and colleges to well-funded universities such as Harvard and Stanford labs, as well as major US national laboratories, including Agung, Lawrence Livermore and San Diego, as well as laboratories in major companies in Germany, the Netherlands, France, Japan, South Korea and China.

There is also a clear and urgent need to reduce the need for humans to emit greenhouse gases. By replacing fossil fuel energy, batteries will play a big role. Consumers clearly need renewable energy: for example, electric and hybrid car sales are growing strongly.

Better batteries offer two big awards: first, affordable electric vehicles, which are the backbone of our future “mobile society”; second, more flexible, decentralized power grids, because advanced stationary batteries will be lower Prices keep the electricity supply to our homes and factories.

Ending "mileage" anxiety

The originally proposed electric and hybrid vehicles were modest, with a range of 40-100 miles per charge (except for the high-priced Tesla electric cars rated 265 miles), and only under ideal conditions. However, the second generation will soon reach 200 miles. South Korea's big company, LGChem, supplies the Chevrolet Volt and Ford Focus with battery packs, and its updated lithium-ion design is reported to bring these cars to 200 miles in 2016. Tesla Electric's chairman and major shareholder, Elon Musk, said his company was working on new batteries in August this year, raising the company's driving range to 500 miles.

At the same time, the cost of batteries is declining. According to research firm Navigant, the price of laptop batteries was about $1,000 per kWh five years ago, and today's prices are close to $250 per kWh. In July 2012, McKinsey Company reported that the price of advanced lithium-ion batteries for automobiles will fall from $500 per kilowatt-hour in 2011 to $160 per kilowatt-hour. According to Favhan, the volume of batteries will increase from $12 billion today to $75 billion by 2020.

In the near future, battery cars will compete with gasoline-powered cars at cost. Musk once said that the battery-powered "Holy Grail" is $100 per kilometer - he expects to be realized in "five to seven years." Tesla is working with Panasonic Corporation of Japan to build a $5 billion "battery factory" in Sparks, Nevada, to manufacture advanced batteries that are profitable on a scale. It is expected to produce 500,000 battery packs per year, doubling the world's lithium-ion battery production.

Powerful BYD Qin

The battery has three basic components: two electrodes, an anode (negatively charged) and a cathode (positively charged), and an intermediate electrolyte (or commonly known as a battery fluid). What happens is a chemical reaction that closes the battery loop (that is, turns on the light switch), electrons flow from the anode, flow through the electrolyte into the cathode, and flow through the bulb to do work. The ion flow is in the opposite direction. The end result is a neutral state and the battery is either discarded or recharged.

Most car batteries are now rechargeable and use some form of lithium as an electrode, cobalt or carbon as the other electrode, and alumina as the electrolyte. But researchers are eager for the next big thing to explore the progress of "from crawling to sprinting" in battery technology. Some major advances have shown hope for success, with energy densities about three to five times that of lithium ions, which, according to theoretical platinum standards, fuels even more than gasoline.

The most daring concept is lithium-air. Get rid of the traditional metal as the cathode, replace it with carbon, completely reform the battery, and extract the oxygen atoms in the air to replace the oxide in the electrolyte. A team at the Massachusetts Institute of Technology (MIT) proposed a cathode composed of nanowires. This is a very tiny structure built with a single atom, actually made from a genetic variant virus. This is a very tricky material, and the lab design proves to be twice as powerful as a typical lithium-ion battery and recharge faster.

As battery chemistry progresses, new materials like this will become key. Graphene, an ultra-thin (only as thick as atomic) single-layer carbon, was originally manufactured by two Russian scientists at the University of Manchester in 2003 (and won the 2010 Nobel Prize in Physics for this purpose) and developed as an electrode material. Its strength, flexibility and conductivity are surprising, and it can be manufactured on a large scale and cheaply, ordering online for $5 per gram. In the battery, it can drastically reduce the charging time and increase the energy storage capacity. Both XG Science and SciNode systems from Northwestern University and Argonne National Laboratory, based in Michigan, USA, are working on graphene batteries. According to SciNode, its anode provides three times more storage capacity than conventional carbon. According to the China Xinhua News Agency, the company may also have a graphene project.

Graphene is an atomic ratio honeycomb lattice made of carbon atoms

Another promising variant is the lithium-sulfur design, which replaces high-priced cobalt with cheap sulfur and provides extremely high energy density. Scientists at Berkeley National Laboratories have proposed a design that doubles the energy density of lithium-ion batteries, with potential costs as low as $100 per kWh. More research is needed, but this method is very tempting and is said to defeat gasoline.

In addition, the design of iron-phosphate does not require lithium at all. In China, automaker BYD has put E6, an iron-phosphate battery-powered taxi, on the market, driving a mileage of 185 miles. It is based on a battery that BYD calls Fe (iron element symbol). BYD "Qin" is a hybrid car with a maximum power output of 223 kW and a bitt S-type slightly lower. According to the company's test, after 10,000 charge and discharge cycles, the Fe battery still maintains 70% of its capacity. That is 27 years of daily recharge.

Electric taxi produced by Shenzhen BYD Auto Company

Stick to it, "to the dawn"

At the same time, we may be approaching the golden age of “fixed energy storage”. No need to move batteries without weight requirements, meaning developers can use heavier, less unique and cheaper materials. Such batteries provide backup power to make the grid more reliable, and avoid peak energy cost spikes, collecting non-peak renewable wind turbines and solar panel energy, and thus at a low price.

This design tendency reflects the work done on the car, but there are significant exceptions. Pittsburgh-based Aquion Energy specializes in microgrid, partially complete power solutions, including solar, wind or other renewable energy sources in remote areas. Its advanced battery cost is about the same as an old-fashioned lead-acid battery, but its duration has doubled.

At the Massachusetts Institute of Technology (MIT), Donald Sadoway and his team developed solid-state batteries that lasted for a long time. According to them, it is easy to scale up. The material is ordinary and inexpensive, but the design is completely innovative: it stays completely liquid, accelerates electron and ion exchange, and the battery itself is kept at high temperatures, relying on strict insulation to maintain 350°F or higher, but still produce energy at 75% efficiency. , more than double the internal combustion engine. AMBRI (formerly Liquid Metal Battery Company), based in Cambridge, is manufacturing the battery, which is said to last for decades and has almost no degradation in performance. Even with full discharge, it is expected that the 10,000 cycle capacity will still be 98%. This is a huge success. Next year, the prototype will be sent to four states for field testing.

At this time, the competition is to compete with local power companies, and there is no advanced battery in this place. If you only do “peaking” and add extra power to the grid during peak demand, the rate may double or even triple (usually in the afternoon) and the place will pay in person.

Of course, there is still a long way to go. As the battery pioneer Whitingham said, "We only know a little fur." As the world makes every effort to get rid of its dependence on fossil fuels, batteries are likely to play an increasingly important role in our daily lives and may help save the planet.

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