The development of lithium battery technology does not conform to "Moore's Law"

　　Although various mobile phone manufacturers claimed at the press conference that their products use large-capacity batteries, the phenomenon of mobile phones being charged once a day is still common. In the case of frequent use by users, mobile phone batteries cannot even last for a day. The weak battery life of mobile phones has become the biggest pain point for users when using smartphones, and it has also become the shortest board that restricts the development of smartphones.

　　In order to rush to launch new products before Apple's September conference, various mobile phone manufacturers began to intensively release new mobile phones in July and August. In the face of faster processors, clearer screens, and higher-pixel cameras, people’s demand for smart phone performance has been fully satisfied, but there is still one parameter that is difficult to satisfy consumers, that is, the battery life of mobile phones. .

　　Although various mobile phone manufacturers claimed at the press conference that their products use large-capacity batteries, the phenomenon of mobile phones being charged once a day is still common. In the case of frequent use by users, mobile phone batteries cannot even last for a day. For the "head-downers" who can't live without their mobile phones all the time, the most panic thing is that the mobile phone displays a low battery reminder. No matter how good the performance is, once the battery runs out, the mobile phone will immediately become useless.

　　In recent years, the development speed of smart phones has surpassed Moore's Law. According to estimates, from 2005 to 2015, the growth rate of smart phone processor clock speed was 1500%, and the growth rate of camera pixel reached 5000%. Faced with the geometric growth of mobile phone performance, the development of mobile phone battery technology seems to be slow. In the past 10 years, although the energy density of smart phone batteries has increased by 7.2% per year on average, the battery capacity has doubled, but the standby time of mobile phones has not been A qualitative change. The weak battery life of mobile phones has become the biggest pain point for users when using smartphones, and it has also become the shortest board that restricts the development of smartphones.

　　Why is the battery on the phone always insufficient?

　　Users always complain that the battery of their mobile phones is not enough, so you might as well learn about the battery that provides battery life. At present, most mobile phones use lithium-ion batteries. Lithium battery technology came out as early as the 1970s, but it was not until 1992 that Sony Corporation of Japan launched the first batch of commercial lithium batteries, which formally replaced the earlier ones. Ni-MH batteries used in "Big Brother" mobile phones.

　　Lithium batteries replace Ni-MH batteries, bringing a qualitative leap in the battery life of digital products, which also makes people rarely complain about mobile phone batteries in the era of feature phones. However, after the arrival of the smart phone era, users increasingly feel that the battery is "tight" when using mobile phones. In the era of feature phones, the hardware power consumption of mobile phones is very low, and the software is very simple, so the battery life of mobile phones is not so obvious. However, in the era of smart phones, the performance of mobile phone components continues to improve, and the power of lithium-ion batteries has begun to be somewhat stretched.

　　In the era of smart phones, touch-screen operation makes users continue to pursue larger screens. However, the large-screen configuration is the main reason for the rapid power consumption of smart phones. "The LCD screen of a smart phone is a major consumer of electricity. Once the screen is lit and the backlight module of the screen starts to work, the power consumption of the phone will soar. Take an Android smart phone in normal use as an example. , By looking at the battery power consumption rankings, you will find that the power consumption of the screen basically accounts for more than 50% of the total. This is why manufacturers claim that their mobile phone batteries can stand by for ten to tens of days, but in actual use The battery is still not enough." Li Xinghua, a mobile phone hardware test engineer, said in an interview.

　　From feature phones to smart phones, not only the screens of mobile phones continue to increase, but the functions of mobile phones are also getting stronger and stronger. When using mobile phones, users no longer have to choose a few features that come with them like in the feature phone era, but can install different applications according to their needs. This leads to the fact that in actual use, because some programs have been calling GPS and other functions in the background, it will cause the GPS module, communication module and soc chip to continue to work, so that the battery power is quickly consumed.

　　In addition, as mobile phone screens continue to grow larger, users are increasingly pursuing thinner and lighter mobile phones for ease of manipulation, which also limits the battery life of mobile phones to a certain extent. In the trend of mobile phone manufacturers pursuing thin and light design, it is often seen that the battery life of some flagship models is not as good as the performance of the previous ones. In the era of feature phones, 15mm body thickness is the norm, but nowadays, some manufacturers have developed smartphones with 6000mAh batteries, but the body thickness reaches 11.9mm, which is considered by most consumers to be too bloated.

　　The continuous improvement of the performance of mobile phone components and the continuous thinning of the body has made it difficult for lithium battery technology to keep up. Another reason for the tight battery power of mobile phones is the continuous spread of "mobile phone dependence". In the past, people rarely stared at their mobile phones all the time except for calling and texting. Nowadays, mobile phones have been held by people from time to time, such as WeChat, Weibo, taxi, navigation, shopping, games, office, etc., people’s lives have been completely tied to mobile phones, and the amount of time they use mobile phones is increasing every day. Naturally, mobile phone power is becoming increasingly difficult to meet demand. "It also has a display screen and also requires calculations, but people rarely complain about lithium batteries in digital cameras, because most users use digital cameras much less frequently than smart phones, and people use smart phones every day. At times, more and more heavy use scenarios such as navigation and games, coupled with the trend of large screens and thinner smartphones, have formed a situation where the demand for mobile phone power has increased rapidly, and the increase in supply has been hindered." Technology commentator Qian Sheng accepted an interview Shi said.

　　Curve to save "electricity"

　　The most direct way to improve the battery life of a mobile phone is to make the battery of the mobile phone as large as possible. In order to achieve this in the limited space of the body, more and more mobile phone manufacturers are beginning to imitate Apple's iphone and design the mobile phone battery as Not removable. "Through the'integration' of the battery and the mobile phone, the hard case protection of the original battery is eliminated, and the battery volume and energy density can be increased," Qian Sheng told reporters. However, under the mainstream trend of thinner and lighter mobile phones, the size of the battery cannot be increased indefinitely. Moreover, the shortcomings of this "all-in-one" design are also obvious. Users can no longer prepare a few spare batteries for replacement as in the past, and once the mobile phone is exhausted, they have to find a power source for charging.

　　The battery life of mobile phones is "not powerful" and non-removable, and even gave birth to a new digital consumer product-mobile power, which people are accustomed to calling it "power bank". Today, mobile power products have formed a huge consumer market. According to data, the domestic mobile power market was 16.5 billion yuan in 2014 and is expected to grow to 22 billion yuan in 2015, an increase of more than 30% year-on-year. The reporter found in the investigation that the battery capacity of the mainstream mobile power products currently on the market ranges from 5000mAh to 50000mAh, and some are marked as 80,000mAh. The price of mobile power products also ranges from tens of yuan to thousands of yuan. Alternative "power banks" that use solar energy and hand-cranked charging are also emerging in endlessly. Many mobile power products are also designed by manufacturers to be as beautiful as possible. It is not so clumsy and ugly in use.

　　However, due to the lack of standards, online shopping and mobile power products on the market are mixed and flooded with inferior products. Accidents caused by quality problems are not uncommon. In response to the chaotic situation in the mobile power product market, the official website of the National Standards Commission recently released the national standard "Safety Requirements for Lithium Ion Batteries and Battery Packs for Portable Electronic Products" (GB31241-2014). The standard has detailed test requirements for mobile power products, including more than 30 test requirements such as working parameters and circuit safety, to ensure that mobile power products are safe and reliable. The standard has been officially implemented on August 1, which will make the mobile power product market more standardized in the future. When people are still "unable to get rid of" mobile power products, at least they are using mobile power products to "bottle mobile phones". It can be used safely and at ease.

　　Mobile phone manufacturers have also seen huge business opportunities for mobile power products. Domestic mobile phone manufacturers such as Xiaomi, Meizu, and OnePlus have also launched their own mobile power products, but no matter how safe and reliable mobile power is, it is a burden for consumers.

　　Today’s mobile phones are already highly integrated smart terminals with hardware and software. This has also led many mobile phone manufacturers to try to optimize the battery life of their phones from a software perspective. The reporter learned that most Android phones currently have a built-in power saving mode, and the iPhone ios9 system, which will be released this year, also exposed the "low battery mode" in the beta. When the user turns on the power saving mode of the mobile phone, the power consumption will be greatly reduced, but some functions of the mobile phone will also be limited. The power-saving modes of smart phones mostly reduce the power consumption by reducing the brightness of the screen, turning off WIFI and cellular data networks, and reducing the processor frequency. Some models even provide a simplified main screen or even a black-and-white display on the screen. "The way to extend the battery life of the mobile phone.

　　Qian Sheng told reporters that using the power-saving mode allows users to barely maintain the phone when the battery is low, but its essence is nothing more than turning the smartphone back into a functional machine when the battery is low, not a fundamental solution. Battery life of the smartphone. In addition, many companies have developed mobile phone applications such as "Battery Doctor" and "Power Saver" to reduce the power consumption of mobile phones by managing background applications, but this seems to be a drop in the bucket under heavy use by users.

　　As the "power bank" and software optimization failed to solve the problem of mobile phone battery life, R&D staff began to try new ways to solve the problem, and they put the breakthrough in the charging time of the mobile phone. Users complain about mobile phone batteries, on the one hand because of insufficient power, and on the other hand because of the long charging time. Taking the entry-level 2000mAh battery configuration of this year's smartphone as an example, it usually takes about 3 hours to fully charge such a mobile phone. If the charging time can be greatly reduced, the user experience will be greatly improved. pregnancy.

　　In order to improve the battery life of mobile phones, people seem to have tried various methods, but they are still a desperate choice. If you want to really solve the problem of weak battery life of mobile phones, you should also look for more from the battery technology itself. breakthrough.

　　Will the future be all right?

　　Someone once said that if you think you are smart enough and you are lucky, then you should engage in battery technology research. As long as you hold the new rechargeable battery patent in your hands, then you will become the top rich man in the world. More importantly, you will become the technological hero of this era. Andy Chu, an executive of the new energy startup A123, said that energy storage is a game that big players only enter, because too many things can go wrong with the battery. As a branch of applied electrochemistry, battery technology can be described as difficult in its progress, but every step forward will bring huge surprises and changes to the world.

　　The battery technology of smart phones does not seem to develop as rapidly as the mobile phone itself, but in fact, people's research on battery technology is not stagnant. Whether it is the lithium anode battery led by Stanford University, the silicon battery researched by the University of California, Riverside, or the “nano generator” that Nokia and Queen Mary University of London collaborated to generate electricity by absorbing environmental noise, they are constantly exploring the future of battery technology. . Tel Aviv University in Israel also accidentally discovered a peptide molecule with extremely high capacitance while researching drugs for the treatment of Alzheimer’s. These researchers also set up a special company, hoping to develop a mobile phone battery that can be fully charged in one minute. However, these technologies that sound good can only work in high-end environments such as laboratories.

　　News about battery technology progress is exposed by the media every year or even every month, but it takes a long process to realize industrialization. New battery technologies require long-term experiments to solve various problems in batches. Only when basic conditions such as high efficiency, stability, and ease of packaging and use are achieved, can new battery technologies have commercial potential. At present, these new battery technologies are far from large-scale manufacturing. There is still a long way to go with commercial use. In addition, consumer electronics giants such as Apple, Google, and Dyson are also actively cooperating with battery manufacturers, hoping to achieve technological breakthroughs, but it is difficult to make huge progress in the short term.

　　It will not happen overnight for the future "super battery" to get out of the laboratory and come to consumers. The historical mission of lithium-ion batteries is likely to continue for a long time in the future.

　　Faced with the development bottleneck of the battery industry, it is like facing a dry well with no water. We can relocate and build a new well, but we may not be able to achieve our wish. We can also try to drill the well in front of us deeper. With technology to tap greater potential, is there still room for improvement in lithium-ion battery technology? 　　 From the first lithium-ion battery made in the 1970s, 20 years later, Sony officially put lithium-ion battery technology into commercial use. Now that it is becoming more and more mature, the development of lithium-ion battery technology has passed nearly 50 years. But many people in the industry believe that from the perspective of reducing production costs and increasing energy density, there is still a lot of room for improvement in lithium-ion batteries.

　　The new darling of the auto industry, Tesla’s electric cars use their own lithium-ion batteries. Someone once disassembled Tesla’s battery pack and discovered that it is composed of batteries like AA batteries. In order to supply its own electric cars, Tesla invested 5 billion US dollars to build a super battery factory in Nevada, USA. Relying on the cooperation with Panasonic, Tesla has innovated the battery production process. Since 2008, Tesla's battery composition cost has been reduced by nearly half, which is 30% lower than the production cost of ordinary lithium-ion battery manufacturers. The efficiency of energy storage has increased by nearly 60%. It can be seen that there is still a lot of room for improvement of other lithium-ion battery manufacturers.　　The energy density of lithium-ion batteries has been rising in shocks for the past 10 years. In 2005, lithium-ion batteries using polymer electrolytes began to gradually replace the previous liquid lithium-ion batteries. Polymer lithium-ion batteries are more excellent in electrochemical characteristics, and are more flexible in shape, which can make the volume utilization rate of the battery more High, lithium-ion batteries usher in a big increase in energy density. However, around 2008, the increase in the energy density of lithium-ion batteries began to slow down. As battery safety issues have attracted everyone’s attention, battery manufacturers have begun to continuously improve battery safety indicators and thicken the lithium-ion battery casing. In the following three to four years, the energy density of mobile phone batteries has remained stable. After 2013, battery manufacturers have improved the compaction density of battery materials through continuous improvement of the process, and the energy density of lithium-ion batteries has increased again.

　　At present, the energy density of mainstream mobile phone batteries has reached about 600Wh/L (watt-hours per liter). The Blue Devils Digital, which has joined with BYD to enter the smartphone market, has also been rumored to use 800Wh/L ultra-high energy density on its own mobile phones. Battery. In recent years, my country’s