Will lithium titanate batteries become a new force in new-energy automotive battery technology?

Thanks to Dong Mingzhu's strong support, the lithium-titanate battery suddenly stood under the dazzling spotlight. From the past, most people were not familiar with the short-term "halo-added", lithium-titanate battery can be described as "out of the limelight." However, people's different views on lithium-titanate batteries have also caused a lot of controversy. The focus of the controversy is mainly on whether "lithium-titanate batteries will become the mainstream of batteries in the future."

BYD Chairman Wang Chuanfu once said that although there are certain markets in some local areas, especially under extremely low temperatures, it is not as good as some people say. It also needs to "practice internal skills"; Huangshilin, president of the Ningde era, also told reporters that the energy density of lithium-titanate batteries is relatively low and will not be too mainstream in the future.

In addition, other people who hold a negative view said that the carbon negative fast recharging battery technology has developed rapidly, the energy density is high, and the cost is low. In the future, it will become the mainstream battery technology. Lithium-titanate batteries "have no future."

Proponents of lithium-titanate batteries say that no power cell is perfect. The word "mainstream" is just a hat that has been withheld by the times. It is not a standard for judging companies. The market is the "touchstone." Give the new technology some time and respect, speaking with facts, is the test of things right and wrong.

So what is the controversial lithium-titanate battery?

Learn about lithium titanate batteries

According to the interpretation of relevant experts, lithium-titanate itself can not provide lithium sources, so it can only be used in conjunction with electrode materials containing lithium. When lithium-titanate is a positive electrode, the negative electrode can only be a metallic lithium or lithium alloy. At this time, the battery voltage is about 1.5 V. Lithium-titanate can be used as a negative electrode and a positive electrode material such as LiCoO2 or LiMn2O4 to form a battery having a voltage of about 3V.

Although lithium-titanate can be used as both a negative pole and a positive pole, because the potential of Li + / Li is 1.5 V, there is not much research and application as a positive electrode material. Therefore, the lithium-titanate battery we usually refer to generally refers to a power lithium or energy storage battery with lithium-titanate as the negative electrode.

What are the advantages of lithium-titanate batteries?

As power batteries, consumers 'most important concerns are mainly focused on the five key indicators of safety, stability, cycle life, wide temperature resistance, charging speed, and energy density. Under the current technical conditions, only batteries with balanced performance indicators can adapt to the wider operating environment, and at the same time ensure the safety of users, reduce the cost of use and increase the efficiency of use, thus becoming the mainstream of the market. Compared with traditional lithium manganese acid batteries and lithium iron phosphate batteries, lithium-titanate batteries have obvious advantages in these aspects.

1, good security and stability.

Once the traditional carbon electrode is filled with lithium, the surface of the electrode is easy to precipitate metallic lithium, and its reaction with the electrolyte will produce flammable gas, which will bring about safety hazards. The potential of lithium-titanate is higher than that of pure metallic lithium, and it is not easy to produce lithium crystal branches. The discharge voltage is stable, and therefore the safety performance of lithium batteries is improved. There have been third-party tests of lithium-titanate batteries and found that under rigorous tests such as acupuncture, extrusion, and short circuit, there is no smoke, no fire, and no explosion, and the safety is much higher than other lithium batteries. Therefore, there are also many industry insiders who believe that lithium-titanate is very suitable for use in areas such as military industries that require high battery stability.

The safety and stability of electric vehicles is the most important indicator of consumers 'concern. No matter how far the mileage is, if the safety problem is not solved, consumers will only drive a car with no time bomb. And the Super safety performance of lithium-titanate batteries will undoubtedly be favored by consumers.

2, fast charging performance is excellent.

Compared with carbon negative electrode materials, lithium-titanate has a higher diffusion coefficient of lithium ions and can be charged and discharged at a higher rate. While greatly shortening the charging time, the impact on the cycle life is small and the thermal stability is also strong. According to the test, the latest technology developed lithium-titanate batteries can be filled in about ten minutes, which is a qualitative leap over traditional batteries.

Too long charging time has been a difficult obstacle in the development of electric vehicles. In general, slow-charging pure electric buses require a charging time of at least 4 hours, and many pure electric passenger vehicles have a charging time of up to 8 hours. Fast charging of electric vehicles is the trend in the future, and consumers do not want to waste too much time waiting to recharge this link.

3, long cycle life.

Battery cycle life determines the cost performance of the entire new energy vehicle, which is the main competition point after the new energy vehicle is out of subsidy policy in the future. The extension of the battery life of the car allows consumers to afford and afford it.

Other traditional lithium-ion batteries, such as lithium-iron phosphate batteries, will experience significant capacity decay and shortened life during use, which not only affects the normal use of users, but also increases the cost of battery replacement. This poor use experience is likely to deter consumers from electric vehicles, which is not conducive to the sustainable development of the new energy vehicle industry. Lithium-titanate batteries solve these problems well.

When lithium-titanate battery is charged and discharged, lithium ion intercalation and deintercalation do not cause a change in the crystal structure of lithium-titanate, and thus have little effect on the structure of the lithium-titanate material. For this reason, lithium-titanate is also known as "zero strain material." Lithium-titanate battery is superior to the current lithium iron phosphate battery with “slow charge for up to 5 years and fast charge for up to 2 years”. According to the test data, the average battery cycle life is 3,000 times, and the lithium-titanate battery can be fully charged and discharged up to 30,000 times. After 10 years as a power battery, it may be used as an energy storage battery. 20 years. This also means that the lithium-titanate battery can achieve the same life cycle as the vehicle, and the user does not need to replace the battery in actual use, and almost does not increase the later cost.

4, wide temperature resistance is good.

The spinel structure of lithium-titanate batteries has three-dimensional lithium ion diffusion channels, so lithium-titanate batteries perform very well at high and low temperatures. General electric vehicles will have problems with charging and discharging at minus 10 °C. Lithium-titanate batteries have good wide temperature resistance and high durability. They can be normally charged and discharged at minus 50 °C to zero at 60 °C, whether in the frozen North or in the hot South. Vehicles will not be affected by the battery "shock" and eliminate the user's worries.

These advantages of lithium-titanate batteries can greatly save the site construction and staffing costs of charging stations, and are more suitable for the promotion and application of public transportation. The public transportation system is the "main battlefield" for the promotion and application of new energy passenger cars in China. Feedback from the public transport market, which currently has the highest proportion of new energy vehicles, shows that the fast charging method is more suitable for the actual needs of the current public transport market. A public transport company in Handan, Hebei Province has been operating a new energy bus using lithium-titanate batteries for more than two years. The relevant person in charge of the bus is: "A car can be filled in 6-10 minutes, and the gap between the driver's shift and rest can be filled. good. "

Lithium titanate battery's "beauty deficiency"

Lithium-titanate batteries have obvious advantages and their disadvantages are also obvious. For example, the energy density is relatively low and the endurance is weak. After testing, lithium-titanate has a gram capacity of 160-170mAh/g, only half of the traditional graphite negative electrode material, and a lithium potential of 1.5 V, which will greatly lose energy density.

Lithium batteries are recharged and recharged by lithium ions. Lithium batteries in different battery systems consume the same lithium element per hour. Therefore, the higher the energy density of the battery system, the higher the utilization rate of lithium, and the lithium titanate batteries. The energy density is less than half of the lithium iron phosphate battery. The utilization rate of lithium is also less than half that of lithium iron phosphate batteries, which not only causes serious waste of lithium resources, but also leads to high cost of lithium-titanate batteries. In addition, the cost of titanium is high, and problems such as the lithium-titanate process also need to be solved urgently. At present, the cost of the triple-lithium-titanate battery is about 2-3 times that of the triple-graphite battery. The high cost limits the amount of lithium-titanate battery installed, which is the objective short plate of the technical route.

Development Status of Lithium Titanium Battery

Although there are still some deficiencies in lithium-titanate batteries, its significant advantages in safety performance, charging and discharging, and cycle life point to the pain of other types of power cells on the market today. At present, domestic companies engaged in the development of lithium-titanate batteries have silver dragons, micro-macro power, etc. With the increase of research and development of lithium-titanate by these companies, some technical difficulties will also be gradually broken through.

It is understood that Yinlong, which has mastered the core technology of lithium-titanate, has developed a fourth-generation high-energy density lithium-titanate battery, which has a cost decrease of 40 <UNK> compared to the third generation, and an energy density increase of 60 <UNK>. Yinlong also mastered the core technology of hydrogen and titanium research and development, which will effectively solve the problem of battery energy density. At present, Yinlong has not only achieved the successful operation of products in more than 30 cities in Beijing, Shijiazhuang, Handan and Zhuhai. It also successfully entered overseas markets such as the United States, Germany, and France. In 2015, Yinlong sold nearly 7,000 orders throughout the year. It is understood that in the future, Yinlong will also solve the problem of short mileage of new energy vehicles through the combination of lithium-titanate batteries and fuel cells.

For many years, Micro-Power has been focusing on the research and development of core materials for lithium-ion power batteries, and the development of lithium-titanate batteries as its main strategic direction. In 2011, Micro-Power invested in the first fast-charge bus line in China, achieving annual sales of 1.5 billion yuan by 2015. After years of research, Micro-Power selected a lithium-titanate porous composite carbon that can withstand high current and has a spinel structure as a negative electrode material. In 2013, the second generation fast-charge battery LpCO lithium battery was released in order to avoid fast. The high-power current is a threat to battery safety, combined with non-combustion electrolyte, high porosity and high permeability diaphragm technology and STL intelligent thermal fluid technology to improve the safety of charging. On June 9, 2016, at the award ceremony of the “Transformation Innovation Business Award” held by the Financial Times, Micro-Power won the “Low Carbon City Transformation Innovation Achievement Award” and the “Transformation Innovation Business Excellence Award”. Became the only Chinese company to be selected for the ceremony.

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Although the outside world's debate on lithium-titanate batteries has not yet stopped, the controversy is not a bad thing. Let the different voices be fully expressed, and the truth will become clearer and clearer. Although the controversy over lithium-titanate batteries will affect the market and consumer confidence in lithium-titanate batteries to some extent, it may also affect investment decisions, but from the five major advantages of lithium-titanate batteries, the future lithium-titanate battery technology continues. breakthrough, As well as the operating experience of companies such as Yinlong and Micro-Power in lithium-titanate supporting cars, it can be judged that lithium-titanate batteries may become a "living force" of new energy automotive battery technology in the future.

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