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- September 24, 2022
- battery materials
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- 07 mins
Research status and application prospect of lithium titanate cells
At present, commercial lithium-ion batteries mainly use graphitized carbon materials as negative electrodes. Graphite, which is rich in resources and excellent in performance, plays an important role in the lithium-ion battery industry as negative electrodes. To know more about cathode, you can click our ternary cathode material article article.
However, the graphite anode battery will suffer structural damage during the cycling process, and will also cause irreversible capacity loss due to lithium precipitation, which is difficult to meet the requirements of high rate and long life.
In order to overcome these shortcomings, the research of lithium titanate cells have gradually become a hot spot. Lithium titanate is a zero-strain material with almost no volume change during the intercalation and deintercalation of lithium ions, and its cycle stability is very good. It also has a lithium ion diffusion coefficient much higher than that of graphite.
In addition, no SEI film is formed on the surface of the lithium titanate negative electrode, which avoids the deterioration of the battery performance due to the destruction of the SEl film during the battery cycle, and has extremely high safety performance.
Research status of lithium titanate cells
Lithium manganate/Lithium titanate cells
Spinel-type lithium manganate is one of the mainstream cathode materials on the market. In the crystal structure, oxygen ions are closely packed by face-centered cubic, and lithium ions can be reversibly deintercalated from the spinel lattice without causing structural changes. Collapse has the advantages of high voltage, easy synthesis, low cost, and environmental friendliness.
The 3Ah lithium titanate cells has a capacity retention rate of 95% after 30,000 charge-discharge cycles at a 10C rate of 100%. The 50C rate discharge capacity remains 94% at room temperature. It is discharged at a rate of 1C at a low temperature of -40°C, and the capacity is 80% of that at room temperature. It has excellent cycle performance, rate performance and low temperature performance.
The experts also compared the safety performance of lithium manganate/graphite and lithium manganate/lithium titanate batteries. After the two batteries were placed in a 100 ℃ oven for 12 hours, H2, C2H6, CH4 were generated inside the lithium manganate and graphite batteries. and many other flammable gases, while the lithium manganate and lithium titanate batteries do not generate any flammable gases, and the safety performance is significantly improved.
Ternary/Lithium titanate cells
Nickel-cobalt-manganese ternary material combines the advantages of a single metal oxide, high specific capacity, good structural stability and thermodynamic stability, and is a promising cathode material for lithium-ion batteries.
20Ah ternary/lithium titanate cells, the 8C discharge capacity at room temperature is almost the same as the 1C discharge capacity. The 1C discharge capacity at low temperature -30 ℃ is 80% of room temperature. 3C, 100% charge and discharge cycle 6000 times, the capacity retention rate is 86%.
After 365 days of full-charge storage at 25 and 45°C, the capacity retention rates were 88% and 73%, respectively. The battery has excellent low temperature performance, rate cycling performance and storage performance.
Scientists used the surface-treated lithium titanate as the negative electrode and the self-made nickel-cobalt-manganese ternary material as the positive electrode to prepare a 18650 lithium-ion battery. The capacity retention rate of 14,000 cycles at 25°C and 3C was 75.8%.
During the 1C and 5V overcharge test, the battery did not smoke, catch fire or explode, and the maximum surface temperature was only 35°C, showing good anti-overcharge performance.
Lithium iron phosphate/Lithium titanate cells
As a cathode material for lithium-ion batteries, lithium iron phosphate has high reversible capacity, stable voltage platform, and excellent safety, cycle life and overcharge resistance.
The 18650 type 0.8Ah lithium-ion battery prepared by using 2% carbon-doped nano-lithium iron phosphate as the positive electrode and lithium titanate as the negative electrode can be charged at 10C, discharged at 5C, and cycled 20,000 times at 100% charge and discharge, and the capacity is almost unchanged. 15C charge, 5C discharge, 100% charge-discharge cycle 30000 times, the capacity retention rate is 95%, and the high-rate cycle performance is extremely excellent.
Using lithium iron phosphate as the positive electrode material, a 32650 type 4Ah lithium titanate cells was designed, and the battery has a very stable voltage. But at low temperature -20 ℃, the 1C discharge capacity is only 44.9% of the normal temperature discharge capacity.
However, lithium iron phosphate is still popular in lithium battery industry and it is widely adopted in many lithium iron phosphate battery suppliers. In order to offer you with more information, you can read our top 10 lithium iron phosphate power battery manufacturers in China article.
It can be seen that the lithium iron phosphate/lithium titanate cells has excellent cycle performance and stable voltage platform, but the low temperature discharge performance is poor.
Lithium cobaltate/Lithium titanate cells
Lithium cobalt oxide occupies an important position in the lithium-ion battery cathode material market due to its simple production process, high specific capacity, and outstanding comprehensive performance. It is widely used as a lithium-ion battery cathode material for mobile phones, notebook computers and other portable electronic devices.
The lithium-ion battery prepared with lithium cobaltate as the positive electrode material and lithium titanate as the negative electrode material can be cycled 500 times at a rate of 2.5C at 60°C, with a capacity retention of 83.6%. The lithium cobalt oxide/lithium titanate cells with a capacity of 5350mAh, the battery discharge platform is 2.2V, and the battery is charged and discharged at 1C, 3C, 5C and 7C rates respectively. When the charge and discharge rate is less than 7C, the charge and discharge capacity reaches 1C.
More than 90% of the charge and discharge capacity. Under the low temperature environment of 0, -20 and -40 ℃, the 0.5C discharge capacity of the battery is 98.8%, 82.8%, and 58.6% of the room temperature discharge capacity, respectively.
Application prospect of lithium titanate cells
Lithium manganate/lithium titanate cells has excellent rate performance, cycle performance and good high current high and low temperature discharge performance, which can meet the requirements of rapid discharge under different temperature environmental conditions. It is very suitable for low temperature power supply or full temperature range power supply in transportation, military, aerospace and other fields, and has broad application prospects.
Ternary/lithium titanate cells has excellent cycle performance, good rate performance and high and low temperature performance. It is one of the preferred lithium-ion battery systems in the field of power energy storage. It also occupies a large proportion in the field of power batteries. The most promising lithium titanate system lithium-ion battery.
The lithium iron phosphate/lithium titanate cells have good cycle performance and safety performance, the battery voltage is stable but the voltage platform is low, and the low temperature performance needs to be improved. It is suitable for fields with strict voltage requirements.
Lithium cobalt oxide/lithium titanate cells have significant advantages in rate charge-discharge performance and rate cycle performance, as well as high and low temperature discharge performance. However, the prices of lithium titanate and lithium cobalt oxide materials are both high, and their applications are greatly restricted. .
In addition, the lithium nickel manganate/lithium titanate cells has a high voltage platform and energy density, and is also a current research hotspot, but the preparation process of the lithium nickel manganate material is not fully mature, and it can work stably at a high voltage of 4.7V. The electrolyte has yet to be developed, so it has great research value and room for improvement.
The analysis results of the research status of different lithium titanate batteries show that the lithium manganate/lithium titanate cells and the ternary/lithium titanate cells have excellent comprehensive performance and are currently the most ideal lithium titanate system lithium ion batteries. And the application prospect is broad.
The lithium iron phosphate/lithium titanate cells has good cycle performance and safety performance, but it is only suitable for fields with stable voltage platform and low voltage requirements. The comprehensive performance of lithium cobalt oxide/lithium titanate cells is not as good as that of other lithium titanate system batteries, and the material cost is high, making it difficult to face the market.
The preparation process of lithium nickel manganate raw materials and high-voltage electrolyte is the biggest obstacle to the commercialization of lithium nickel manganate/lithium titanate cells.
Summary
The energy storage market is full of prospects and development potential. Here is a top 10 energy storage battery manufacturers in China list for you to know about the industry tendency. Lithium titanate cells have the characteristics of being suitable for peak regulation and frequency regulation of large power grids. The rise of the grid energy storage service market in the future is an inevitable trend, and the market scale of lithium titanate cells will expand more and more.
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