Main content:
Lithium titanate battery is a lithium-ion battery that is used lithium titanate as the anode material. And some lithium ion battery anode material companies would combine it with lithium manganate, ternary materials or lithium iron phosphate and other cathode materials to form a 2.4V or 1.9V lithium-ion secondary battery. In addition, it can also be used as a cathode to form a 1.5V lithium secondary battery with a metal lithium or lithium alloy anode.
1. Characteristics of lithium titanate battery
The difference between lithium titanate battery and traditional ternary and lithium iron phosphate batteries is that the anode material is lithium titanate, and the characteristics of lithium titanate battery are: safer, low temperature characteristics, rate performance, and cycle life.
- Safety: through a series of research experiments in the industry, needle times, gunshots, burning, etc.
- Long life: better than traditional lithium batteries
- Fast charging and discharging: good rate performance
- Wide temperature resistance: can be used normally in extreme cold conditions
2. Lithium titanate vs other lithium batteries - pros and cons comparison
① Pros of lithium titanate battery
● Safety
Lithium titanate battery:
When a short-circuit fault occurs, the ohmic impedance increases sharply, suppressing the discharge reaction, and will not cause excessive instantaneous current and temperature rise; Lithium titanate battery itself is not flammable; The charging potential platform is slightly negative than 1.55V. Even in the later stage of charging, low temperature or high-rate charging, the potential of the anode will not reach the potential of lithium ions being reduced to metal lithium, and there will be no safety accidents caused by lithium precipitation.
Other lithium batteries:
Internal short-circuit events are prone to occur; It is inherently flammable; The potential of lithium intercalation is about 0.1V. When charging at low temperature and high rate, lithium metal is easy to precipitate on the surface of the anode, which will puncture the diaphragm to a certain extent, cause internal short circuit of the battery, and cause explosion and other serious hazards to personal safety.
● Cycle life
The volume change of the lithium titanate battery during the cycle is only 0.1% to 0.3%, which can avoid the structural change caused by the stretching change of the material during the charging and discharging process. Thereby improving the performance of the electrode and reducing the large attenuation of the specific capacity; the cycle process does not produce an SEI film. Other lithium batteries have about 10% volume expansion during the cycle, resulting in swollen battery; a layer of SEI passivation film is formed on the electrode surface. Both of these will reduce its cycle life.
● Excellent fast charging performance
Compared with carbon anode materials, lithium titanate has a higher lithium ion diffusion coefficient and can be charged and discharged at a high rate. While greatly shortening the charging time, it has less impact on the cycle life and has stronger thermal stability. According to the test, the lithium titanate battery developed by the latest technology can be fully charged in about ten minutes, which is a qualitative leap compared with the traditional battery.
Too long charging time has always been an insurmountable obstacle in the development of electric vehicles. Generally, slow-charging pure electric buses are used, and the charging time is at least 4 hours, and the charging time of many pure electric passenger cars is as long as 8 hours. Fast charging of electric vehicles is the future trend, and consumers do not want to waste too much time waiting for charging.
② Cons of lithium titanate battery
The anode of lithium titanate battery uses lithium titanate. Compared with the mainstream lithium battery with graphite anode, the market share is very small. Statistics show that in new energy buses, the market share of lithium titanate batteries is about 3%, which is far lower than the 88% market share of lithium iron phosphate batteries. In the field of passenger vehicles, lithium titanate batteries, together with other minority technologies, share 3% of the market space.
3. Application of lithium titanate battery
Application scenarios: mobile, communication application providers, national grid, rail transit, military systems Power battery, energy battery, lithium titanate communication base station backup power supply In the past two years, lithium titanate batteries have been successfully applied in two-wheelers and tricycles.
4. Why did lithium titanate battery not become the mainstream
The main reasons for this phenomenon are as follows:
● As for the long service life claimed by lithium titanate battery, it is more difficult to be certified. Battery life is also affected by the combination of cathode material, electrolyte, separator, and operating temperature. Lithium titanate as the anode also has problems such as flatulence and reduced consistency after long-term use. At present, it cannot be proved in principle that lithium titanate battery will have a longer life than other batteries.
At present, the cycle life of lithium iron phosphate and ternary batteries can reach more than 2,000 times. According to the general use frequency, it can already reach 7-10 years. With the advancement of technology, 3000 or 4000 cycles will not be too far away. In terms of performance, it can already be used for more than 10 years or even 20 years, which will exceed the general life cycle of a car. Even if the lithium titanate battery achieves a long life, it has no advantage.
● Few companies make lithium titanate battery, which will lead to less R&D investment in the industry as a whole. Judging from the current R&D investment and planning investment of lithium battery companies in the world, few companies will focus on developing lithium titanate battery. In the future, other lithium battery technologies will advance faster than lithium titanate battery.
● Lithium battery life, performance, etc. are affected by many aspects, especially the influence of the four major materials. Lithium titanate is only a anode material. No matter how advanced a material is, it is difficult to give the product an unrivaled advantage. What's more, the cathode material is the most important material that affects the performance of lithium batteries.
● The biggest disadvantage of lithium titanate batteries is low energy density and high cost. In particular, the low energy density is determined by the principle and performance of the anode material lithium titanate, and it is difficult to have a large breakthrough space. The cost can be reduced through scale, but based on the weakness of the principle, it cannot be changed through technology.
● The future market space of lithium titanate battery will be very limited. There is basically no room for the auto industry, and the future space for the auto industry will be smaller than it is now. The field of energy storage can be tried, but it will definitely not become the mainstream. Coupled with the high price, compared with the high cost performance of future energy storage, which is expected to be reused by power batteries, the prospect of lithium titanate in the field of energy storage is also worrying.
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