Introduction to the "Past and present" of the ternary lithium power battery

Regarding lithium batteries, we must be familiar with them, but how much do we know about the history of lithium batteries? Hurry and follow the little one to learn!

Lithium-ion battery invention history and future development

Mobile phone batteries are generally divided into nickel batteries and lithium batteries. Among them, nickel batteries have low capacity, memory effect, self-discharge phenomenon, and environmental pollution caused by manufacturing materials, so they have not continued in the mobile phone industry. Although the birth of "lithium power battery" makes up for the shortage of nickel battery, and its high energy and environmental protection characteristics make it the only source of power in the mobile phone industry, people still have some misunderstandings about the "lithium power battery" on mobile phones because In a strict sense, lithium batteries are not rechargeable. Since they are not rechargeable, what is used on mobile phones? Or what kind of lithium power battery? The following small series will answer for you one by one.

First of all, let's take a look at what is a lithium power battery. In fact, the lithium power battery is a lithium primary battery in a strict sense. It contains pure lithium metal and is a one-time, non-rechargeable battery. Due to its own high technical requirements, only a few companies in a few countries are producing such lithium metal batteries.

Before the appearance of lithium batteries, the original battery can be said to be its originator, how was the original battery born? This dates back to the end of the 18th century, when the Italian biologist Galvani was conducting a famous frog experiment. When a metal scalpel was used to contact the frog legs, it was found that the frog legs would twitch. After many experiments, Galvani thought this might be "Animal electricity."

And Galvani’s friend, Volta, saw this phenomenon. After many experiments, it was found that as long as there are two different metals in contact with each other, the space is separated by wet cardboard, leather or other sponge-like things, with or without frog legs. There is a current generated, which negates the idea of "animal electricity." Because Volta recognizes that frog leg contraction is only a manifestation of the discharge process, the contact of two different metals is the real cause of the current phenomenon. Thus, Volta listed the order of zinc-lead-tin-iron-copper-silver-gold, which is the famous voltaic sequence. In 1800, Volta designed a device called a voltaic stack based on this principle. Zinc is the negative electrode, silver is the positive electrode, and brine is used as the electrolyte solution.

The above story is only the history of the invention of the original battery. The primary batteries that are often used by people are zinc-manganese dry batteries, zinc-mercury batteries, zinc-silver button batteries and lithium batteries. Among them, the lithium power battery is derived from the great inventor Edison, which is a battery made of lithium metal or lithium alloy as a negative electrode material and using a non-aqueous electrolyte solution. However, due to the very active chemical properties of lithium metal, lithium metal is processed and stored. In terms of use, the environmental requirements are very high, so lithium batteries have not been used for a long time in that era. Today, with the development of science and technology, lithium batteries have become mainstream. Since lithium batteries have become mainstream in the moment, what are their advantages and disadvantages? Let us first look at its advantages: 1, high energy 2, long service life; 3, high rated voltage; 4, self-discharge rate is very low, which is one of the most outstanding advantages of the battery, less than nickel-hydrogen 1/20 of battery; 5, high temperature and low adaptability, can be used in -20 ° C - 60 ° C environment, after processing, can be used in -45 ° C environment; 6, green, regardless of production , use and scrap, do not contain, do not produce any lead, mercury, cadmium and other toxic and harmful heavy metal elements and substances; 7, production basically does not consume water, is suitable for countries lacking water. Disadvantages: 1, lithium power battery safety is poor, there is a danger of explosion; 2, high production requirements, the cost will also rise; 3, the use of conditions are limited, high and low temperature use is dangerous.

Today, the common battery in mobile phones is a lithium-ion battery, but the electrolyte of a lithium-ion battery is flowing, and it may cause an explosion if it is hit by an external force or a charger that does not meet the standard. In fact, as long as we buy mobile phones from formal channels, proper use can avoid such things.

Since the mobile phone uses a lithium-ion battery, what is the difference between it and the lithium power battery described above? This is due to the early development of lithium batteries. Since the self-discharge rate of lithium batteries is extremely low and the discharge voltage is gentle, it is first used in pacemakers, so that pacemakers implanted in the human body can operate for a long time.

In 1992, Sony successfully developed a commercial lithium-ion battery. The battery's rechargeable nature makes it a source of power for portable electronic devices such as mobile phones and notebook computers. At the same time, the weight and volume of these electronic devices are greatly reduced, the use time is extended accordingly, and the lithium ion battery does not contain heavy metal cadmium, which greatly reduces environmental pollution compared with the nickel cadmium battery. To say the biggest difference between the two, it can be understood that the lithium power battery can only be used once, and the lithium ion battery can be reused. Of course, lithium-ion batteries can also be seen as derivatives of lithium batteries.

In addition, the previous mobile phone industry has also used nickel batteries for a period of time. However, as the preface of this article, since nickel batteries are polluted by the environment, and have memory effects and self-discharge, lithium-ion batteries are born. With its many advantages, it has become the object of favor of manufacturers, and nickel batteries have been labeled as "cold palace", which is why lithium-ion batteries are used in the current mobile phone market.

Speaking of this, I don't know if you are out of the misunderstanding of cell phone battery awareness. First of all, lithium-ion battery is only one kind of lithium power battery, it can also be regarded as a modified version of lithium power battery, and lithium power battery is a branch of primary battery, and It can only be used once and can not be charged, so in a strict sense, lithium-ion batteries can be called mobile phone batteries. What is the difference between a lithium-ion battery and a nickel battery? This point can be seen from the above introduction. Since the nickel battery has a memory effect, the user needs to first use the remaining power of the new machine, and after repeated charging for a few times, thereby exerting maximum efficiency, this is now Young people are very cumbersome to operate.

However, many people still use the charging habits of the nickel battery era, which will greatly reduce the battery life for mobile phones using lithium-ion batteries, because lithium-ion batteries have no memory, and users can follow them during use. With the charge, as long as it is put or overshoot, reducing the charge cycle and extending the life of the mobile phone battery is not a problem.

Here is a small series for everyone to explain what is the charging cycle? In fact, a charging cycle refers to the process of charging the battery from full to empty and then filling it to full. However, this does not mean charging the battery once. For example, when the battery is used halfway through the first day, it is again Fully charged, the same is true the next day. It can only be counted as one cycle, not two. Therefore, it is obviously not advisable for some people to run out of electricity, and some high-quality batteries will retain 80% of their original capacity after several charging cycles.

The current lithium-ion battery is just a technical application to improve the life of mobile phones. It is believed that in the near future there will be more advanced technology to replace lithium-ion batteries, perhaps liquid or gas, but from the perspective of the whole industry, it is a battery. Ultra-fast charging seems to be a technology that is easier to implement.

In addition, in the past, many manufacturers have come up with solutions for mobile phone life, such as LG's solar charging, fuel supply and other technologies, their working principle as the name suggests, solar power is to use light energy to achieve charging, while fuel power is It is the reaction of hydrogen and oxygen extracted from normal fuel to convert chemical energy into electrical energy, while discharging uncontaminated water. Fuel cells of the same weight can provide up to 10 times the power of lithium-ion batteries.

Since there was a solution outside the lithium-ion battery, why didn't the mobile phone's battery life be solved? This is because the solar energy conversion efficiency is low, and there is no market competition condition, and the most direct reason for the fuel cell is the high cost, so from now on, the lithium ion battery can not be replaced.

Looking forward to the future, the research and development direction of mobile phone battery technology should be developed to small size and high battery life. Only by controlling the volume of mobile phone battery can the mobile phone be better used, but should it solve the problem of battery life or solve the volume problem first? I don't know what consumers think, Xiaobian said his own point of view, look at the thickness of the current mobile phone, not the thinnest and only thinner, so I believe that priority is to solve the problem of battery life, is the manufacturer's top priority.

Comments: The above is a review of the history and future development of mobile phone lithium batteries. In fact, today, in addition to the widespread use of lithium batteries in mobile phones and mobile power supplies, lithium batteries in electric vehicles also have a very wide range of applications. Different from mobile phone applications, lithium batteries have also led to a battle for battery materials in new energy vehicle applications!

The cathode materials used in lithium batteries for new energy vehicles are mainly lithium iron phosphate, ternary materials, lithium cobalt oxide and lithium manganate. lithium iron phosphate has a low energy density of about 120 Wh per kilogram, but it has the best thermal stability, high safety and is not easy to deflagrate. The domestic representative car manufacturer adopts BYD. The energy density of the ternary material can be 150Wh or even 200Wh per kilogram. The electric vehicle adopting it is lighter and has a longer cruising range, but the safety is questioned. The representative car company is Tesla, and the foreign car companies such as Nissan Leaf. .

The battle for ternary materials and lithium iron phosphate has a long history. Since its introduction in China in 2004, lithium iron phosphate has been the mainstream route for Chinese power batteries, and there are only a handful of users of lithium manganate and ternary materials. But Tesla's profit in the first quarter of 2013 instantly magnified the advantages of ternary materials. According to the report of BOC International, “The reason why Tesla is not the wind to let the market popularize the ternary materials is that it has a great relationship with the adoption of global supply chain procurement, which can drive the development of the whole industry. At the same time, Tesla is indeed very good. Marketing."

On the one hand, Tesla's success has dispelled the concerns of many car companies. On the other hand, on October 16, 2012, the Ministry of Finance, the Ministry of Industry and Information Technology, and the Ministry of Science and Technology and other three ministries and commissions announced the "Notice on Organizing the Application for the 2012 New Energy Vehicle Industry Technology Innovation Project." The technical innovation goal given by the notice is that the energy density of the battery cells in 2015 is more than 180Wh per kilogram (modular energy density is above 150Wh per kilogram). Liu Lian, the investment director of DT Capital, told reporters that the density requirements mentioned by the three ministries would not necessarily imply the use of that material, but only one ternary material can be achieved by the "energy density".

The above notice is not mandatory, but the energy density requirements are imposed on the car companies. In addition to the Tesla effect, domestic car companies have announced their turn. At the 2014 Beijing Auto Show, Jianghuai, Chery, Beiqi, Zotye and other manufacturers all said that ternary materials will be used in the latest models. This situation has also caused concern among many insiders. A senior lithium power battery said that Tesla's strength lies in the use of batteries provided by Panasonic, but the original package and battery management system. Many domestic car manufacturers and battery factories are going to subsidize, but now whether domestic battery manufacturers can provide consistent batteries, packaging and battery management systems are still doubtful, and it is difficult to assess safety.

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