Why can't lithium titanate battery be widely used
1. What is a lithium titanate battery
Lithium titanate battery is a lithium ion battery negative electrode material - lithium titanate, which can form a 2.4V or 1.9V lithium ion secondary battery with positive electrode materials such as lithium manganate, ternary material or lithium iron phosphate. In addition, it can also be used as a positive electrode to form a 1.5V lithium secondary battery with a metal lithium or lithium alloy negative electrode, but it has not been widely used, why?
2. Those shortcomings make the lithium titanate battery not widely used
Although the lithium titanate battery has excellent safety performance, the research on lithium titanate battery has become a hot spot, but Li, Tis0: the material itself has low electronic conductivity (10-13S/cm) and lithium ion diffusion coefficient (10 -10~10-13cm2/S) greatly limits the application in high-rate charging. Nano-sized Li and TiO particles can expand the effective reaction area and reduce the diffusion distance, thereby significantly improving the rate capability of the material.
However, the process of material particle nanoization is often difficult and requires high cost, and it is currently difficult to achieve large-scale industrial production.
Lithium titanate battery will continue to produce gas in the cycle of use, which will cause the battery pack to swell, especially at high temperature, which will affect the contact between the positive and negative electrodes, increase the battery impedance, and affect the performance of the battery. This is also one of the main obstacles that limit the wide application of lithium titanate as an anode material in batteries.
Lithium titanate (LTO) material is used as a negative electrode material in batteries. Due to its own characteristics, it is easy to interact with the electrolyte and generate gas during the charge-discharge cycle reaction. Therefore, ordinary lithium titanate battery Flatulence is prone to occur, resulting in bulging of the battery core, and the electrical performance will also be greatly reduced, which greatly reduces the theoretical cycle life of the lithium titanate battery. The test data shows that the ordinary lithium titanate battery will experience flatulence after about 1500-2000 cycles, resulting in the inability to use it normally, which is also an important reason that restricts the large-scale application of the lithium titanate battery.
3. Why electric bicycles and cars with lithium titanate battery are not popular
The lithium titanate battery is lighter than the iron-lithium battery (weight advantage), super low temperature resistance, and is very popular in the north (at low temperature, the lithium titanate discharges a minimum of 3c and a maximum of 6c compared to the low temperature of iron-lithium). Compared with the situation, he is completely unaffected), and the safety is high. I did an experiment to pierce the lithium titanate battery with scissors, but the experiment told us that he would not say that the phenomenon of short circuit and sudden smoke and fire occurred.
Although the lithium titanate battery has the above advantages, these disadvantages cause most users not to choose lithium titanate battery electric vehicles:
The lithium titanate battery has a small capacity and is troublesome to assemble. It is very afraid of water. It can be said that soaking in water is equivalent to waste.
4. Advantages of lithium titanate battery
The lithium titanate battery has the advantages of small size, light weight, high energy density, good sealing performance, no leakage, no memory effect, low self-discharge rate, rapid charge and discharge, long cycle life, wide working environment temperature range, safe and stable green environmental protection, etc. Features.
1) When lithium titanate is used as the negative electrode material, the potential platform is as high as 1.55V, which is more than 1V higher than that of the traditional graphite negative electrode material. Although some energy density is lost, it also means that the battery is safer.
2), because the lithium titanate battery can be used safely in both high temperature and low temperature environments, it also reflects its important advantages of wide temperature resistance (especially low temperature resistance). At present, the safe working temperature range of Yinlong lithium titanate battery is between -50 degrees and 65 degrees, while the energy of ordinary graphite anode batteries begins to decay when the temperature is lower than -20 degrees, and the charging capacity is only charging when the temperature is -30 degrees. 14% of the total capacity, it simply cannot work properly in severe cold weather.
3) The last advantage of lithium titanate is its fast charge and discharge capability and high charge rate. At present, the charging rate of Yinlong lithium titanate battery is 10C or even 20C, while the charging rate of ordinary graphite anode material is only 2C-4C.
5. Technology status of lithium titanate battery
An important problem faced by lithium titanate batteries in large-scale applications is cost. At the beginning of the project's development, the price was 46 times that of lithium iron phosphate batteries. Although the performance is significantly better than the existing lithium-ion batteries, economic factors greatly limit the market promotion of lithium-ion titanate batteries. Therefore, in order to achieve large-scale energy storage applications for lithium titanate batteries, it is necessary to carry out technical reconstruction on the basis of existing lithium titanate batteries for electric vehicles. cut costs.
From the perspective of practical application value, lithium titanate batteries are expected to bring customers a lower cost advantage by virtue of their long cycle life. With the increasingly reasonable price, lithium titanate is about to stage a counter-attack. The future market space of lithium titanate ion battery will be very limited, coupled with the high price, compared with the future energy storage is expected to use the high cost performance of power lithium battery secondary utilization, The prospect of lithium titanate in the field of energy storage is also worrying.
The development prospect of lithium titanate battery in China. In the past, the important markets for lithium-ion batteries were portable appliances, mobile phones, laptops, etc. As for the future development prospects, the key to improving the energy density of lithium titanate batteries is the development of high-capacity, high-potential electrolytes and anti-oxidation separators. . The efforts of China's lithium battery industry to develop lithium titanate battery technology will be rewarded handsomely by the emerging markets for electric vehicles, energy storage and industrial applications.
Although lithium titanate batteries do not have an advantage in energy density, with their unparalleled advantages in fast charging, safety and lifespan, and through differentiated competition, they can be used in high charging speed and frequency requirements. Winning a place in the field, the power company will continue to deepen the research and development of lithium titanate fast-charging battery technology, and constantly explore its performance limit and application potential, so as to bring customers a more superior and convenient user experience.
6. What are the main difficulties affecting the promotion of lithium titanate at present? Energy density or cost?
The flatulence problem of lithium titanate is not a big problem at present. The improvement of material coating and electrolyte has greatly improved the flatulence problem.
The advantages of this material lie in high-power charge-discharge and low-temperature performance, but in fact, soft carbon materials can also achieve the same results at a lower cost, so there is no technical difficulty in the promotion of this material. The biggest problem is cost performance and product competitiveness.
In addition, Toshiba recently released a new generation of SCiB batteries. The negative electrode is no longer lithium titanate, but titanium oxide directly used. The status of lithium titanate is even more embarrassing.