Ternary lithium has large capacity, but its safety is not very good and its low temperature performance is not very good. The charge and discharge current is not very large. In addition, the domestic quality is not very good. The number of cycles is not as large as the theory, but the quantity is large, and the various charging and protection boards are relatively mature.
The relative capacity of lithium titanate is smaller. The main reason is that the cell voltage is a little low, but the discharge and charge performance is good and the charging is very fast. Ultra-large current discharge, cycle times are also quite good and low temperature discharge is also very good. But the price is a bit expensive. There aren't a lot of protective panels or anything like that.
Generally speaking, it is best to use iron lith phosphateium for electric vehicles, putting safety first. Ternary and titanic acids have their own strengths, it depends on personal preference. Give me a choice, I like titanate. The main reason is that no one recycles lithium batteries today. If they break down in 3/5 years, will they have to be thrown away?
Advantages of lithium titanate:
1. Stress-free negative electrode, stable structure, can withstand large magnification and ultra-long service life (otherwise the negative electrode material itself will not affect the disadvantages of service life)
2. The potential is high and the lowest potential is greater than the precipitation potential of lithium. There is no need to worry about safety risks caused by lithium precipitation.
3. The thermal decomposition temperature of the material itself is high. Good security
4. A wide ptemperature range, particularly good low temperature performance, can reach -40℃.
Disadvantages of lithium titanate
1. The most fatal drawback is that it is expensive. Titanium dioxide and graphite, you can feel it. The battery price is more than 3 times more expensive than lithium iron + graphite.
2. It is a stress-free material and has a low compaction density. At the same time, the voltage is high, resulting in a low voltage platform for the entire battery. Ultimately, the energy density is too low. The corresponding energy density of lithium titanate + ternary is probably less than 100wh/kg, while the corresponding energy density of graphite + ternary can reach 200wh/kg. Lithium titanate + lithium iron and graphite + lithium iron
3, safety under the same energy density. To achieve the same energy density, the safety of the lithium titanate + nick ratiohigh el and graphite + iron-lithium will be worse. Although lithium titanate itself is safe, the bottleneck will become something else (like the positive electrode)
4, producing gas. SEI film cannot form on the surface of lithium titanate. The electrolyte constantly reacts with the negative electrode, resulting in continuous gas production, which can only be slowed down but cannot be eliminated. This leads to two problems: a. It is not possible to create software packages. (Some people say Yinlong has soft bags. They did it just for energy density and already cut it out in later planning). b. Excessive gas production will affect life and safety. Although there are more than 20,000 cycles in the laboratory, no one dares to promise 20,000 times in batches (unless it is an excessive promise). Compared to iron-lithium from today's leading manufacturers, which can already promisere tens of thousands of cycles, there is no advantage. Excessive gas production will affect the design of safety devices such as explosion-proof valves, potentially causing premature valve explosion or excessive valve pressure.
4. There is no obvious advantage in terms of magnification. At present, fast-charging lithium iron can already charge and discharge at 5-6°C, basically reaching the current level of lithium titanate batteries. The advantageous range of lithium titanate is 5-10°C, but at that time, heat, charger and positive electrode will become bottlenecks.
5, (full)The application space is small. Based on the above comparison of advantages and disadvantages, it can be seen that the obvious advantage of lithium titanate lies in its low temperature performance. However, in an environment where the temperatureis greater than -30°C, the overall performance (price + charging capacity, energy density is not taken into account for the moment) has no advantage (or the price is high) compared to lithium iron + graphite + auxiliary thermal device, plus the disadvantage of energy density, it is difficult to gain PK. This is one of the reasons for the recent poor performance of Yinlong market. It has advantages at temperatures around -40°C, but there are very few application scenarios. It can only have advantages in certain military-industrial scenarios in Northeast Siberia, and the overall market is not large.
In summary, the advantages and disadvantages of lithium titanate , it can be seen that lithium titanate is just a beautiful thing, with limited practical application scenarios and prospects. After all, when there is no obvious performance gap, price is king.