Electric cars: waiting for the battery

If you are fortunate enough to visit California's super-rich regions such as La Jolla, or go to places where high-tech companies such as Mountain View get together, you have the opportunity to experience the future.

To be precise, the future of the automotive industry is understood. Tesla, Nissan Leaf and Toyota Prius or similar cars abound on the road. Electric cars and hybrid cars are common in the traffic flow with ordinary fuel vehicles; charging poles are also installed in many companies, shopping centers, and homes.

If the electric car manufacturers really got their wish, this is the future in which we will be in a certain period of time; car manufacturers are not hesitating to invest heavily to make this reality a reality. The question is, how easy is it to turn the demand in small areas into a national one?

In another part of California, Tesla Motors, founded by Elon Musk, recently proposed plans to build a giant battery factory in the undisclosed US southwest region (a specific site has become a hot topic) ). The so-called “Gigabit Factory” is expected to cost as much as US$5 billion and lithium-ion batteries, which are scheduled to be produced by 2020, can meet the demand of 500,000 vehicles—the annual output exceeds the global annual production in 2013.

However, some people believe that Tesla’s plan seems obsolete by the time the factory opens. IHS Automotive is a leading provider of global automotive business intelligence. Phil Gott, the company’s senior planning director, believes that Tesla’s ambitious plan “I am afraid to think about the week”. The reason is that the new technologies being developed are expected to provide better alternative technologies and solve one of the biggest obstacles that experts have mentioned about electric vehicles.

The problem with electric cars is that the batteries are large and heavy; therefore, the number of installed batteries is limited. For example, the battery pack of the Tesla Model S is tiled on the floor of a car, which is about 2 meters long and 1.2 meters wide. In the top-end model, the battery pack provides approximately 300 miles (482 kilometers) of driving range, after which it is necessary to insert a charging post to charge. The Nissan Leaf wind can run 80 miles (128 kilometers) or so on a single charge. In addition, the charging process is much slower than just refueling.

So, how can we produce a battery with better performance? At the most basic level, batteries contain positive and negative electrodes, separators, and electrolytes. Many different types of materials can be used as electrolytes, and different combinations of materials allow batteries to store different amounts of energy. However, if the material changes, the battery life and security features will change, so there is always a compromise. Lithium-ion batteries are popular, but there have been incidents of lithium batteries short-circuiting on the aircraft, so the carriage is strictly limited. Any more active or unstable battery has safety implications. However, if you design the best combination of materials, you are expected to get a huge return.

In the decades before the recent research work, battery technology has undergone a series of improvements.

The first to come out was lead-acid batteries, which are still widely used today in automobiles. They are huge. Then came the nickel-cadmium (NiCad) battery, which opened up a new era of portable technology's protagonists: mobile devices such as laptops and cell phones, and remote cars when we were kids. A nickel-hydrogen (NiMH) battery then appeared, and the battery capacity or energy density roughly doubled. Lithium-ion (Li-ion) batteries are now commonly used in modern equipment and electric vehicles.

Looking to the future, we are ready to welcome the increasingly complex battery technology, such as lithium nickel manganese cobalt (LiNiMnCo) batteries. The properties of this material are complex; for now, researchers are committed to not only figuring out why these materials work, but also figuring out how to work—the basic physical principles of how electrons move through materials.

Daniel Abraham, a materials scientist at the Argonne National Laboratory in the United States, said: “We at Argonne National Laboratories are studying materials that are expected to double the current energy density of batteries. Let’s dream or imagine first. Want to handle the materials and then work hard to synthesize the materials in the lab."

Currently, several batteries that have attracted attention include lithium-air batteries (more specifically, lithium-oxygen batteries) and lithium-sulfur batteries. If it can be done under all kinds of conditions, the performance of lithium-ion battery is expected to be significantly higher than that of current lithium-ion batteries, and it will increase by an order of magnitude. Abraham said: "This is a very popular area of ​​research."

Indeed, Volkswagen recently suggested that it is studying lithium-air batteries. As the development work has not yet been finalized, the specific chemical/material combination adopted by the public has not yet been disclosed. The company’s engineers are not even willing to say that the technology has been tested in the car, or is still in the “experimental stage” stage.