The lithium titanate battery is a lithium ion secondary battery which is used as a negative electrode material for a lithium ion battery, lithium titanate, and can be composed of a positive electrode material such as lithium manganate, a ternary material or lithium iron phosphate to form a 2.4V or 1.9V lithium ion battery. In addition, it can also be used as a positive electrode, and a 1.5V lithium secondary battery is composed of a lithium metal or a lithium alloy negative electrode. Due to the high safety, high stability, long life and green environmental protection of lithium titanate. As a negative electrode material for a new generation of lithium ion batteries, lithium titanate materials are widely used in new energy vehicles, electric motorcycles, and applications requiring high safety, high stability, and long cycle.
Lithium titanate battery composition
Positive electrode: lithium iron phosphate, lithium manganate or ternary material, lithium nickel manganese oxide.
Negative electrode: lithium titanate material.
Diaphragm: A lithium battery separator that uses carbon as a negative electrode.
Electrolyte: A lithium battery electrolyte using carbon as a negative electrode.
Battery case: A lithium battery case that uses carbon as a negative electrode.
Lithium titanate battery characteristics
Lithium titanate (LTO) material is used as a negative electrode material in batteries. Due to its own characteristics, the material and the electrolyte are likely to interact with each other and produce gas evolution during the charge and discharge cycle reaction. Therefore, ordinary lithium titanate The battery is prone to flatulence, resulting in a battery pack, and the electrical performance is also greatly reduced, greatly reducing the theoretical cycle life of the lithium titanate battery. The test data shows that the ordinary lithium titanate battery will undergo flatulence after 1500-2 000 cycles, which may cause normal use, which is an important reason for restricting the large-scale application of lithium titanate batteries.
The performance improvement of lithium titanate (LTO) batteries is a combination of improved performance of individual materials and organic integration of key materials. In response to the requirements of fast charging and long service life, in addition to the negative electrode materials, other key raw materials for lithium-ion batteries (including cathode materials, separators, and electrolytes), combined with special engineering process experience, have finally formed " The non-flatulence lithium titanate LpTO battery product, and first realized the batch application on the electric bus.
The test data shows that under the conditions of 6C charging, 6C discharge and 100% DOD, the lithium titanate LpTO single cell has a cycle life of more than 25,000 times, and the remaining capacity exceeds 80%. At the same time, the flatulence generated by the battery is not obvious, It affects its life; the actual application of Chongqing fast-charging pure electric bus also shows that after the battery is grouped, the performance of electric performance is also very good, which can guarantee the daily commercial operation of pure electric bus.
Lithium titanate battery advantages
1. Good safety: The most important point of the electric vehicle battery is the high safety. Because of its high equilibrium potential, lithium titanate does not form lithium dendrites in the negative electrode, and has good safety.
2, good cycle performance: because it is a "zero strain" material, and will not undergo structural changes during charging and discharging, has a very superior cycle performance.
3, can quickly charge and discharge: lithium ion diffusion coefficient in lithium titanate crystal is 2 & TImes; 10-8cm-2 / s, an order of magnitude more than graphite negative, can quickly charge and discharge, fast charging ability is to investigate the battery of electric vehicles An important indicator.
4, the operating temperature range is -30 ° C ~ 60 ° C: lithium at the low temperature of the embedding and extraction capacity will be reduced, especially the embedding ability, lithium titanate negative electrode at -30 ° C charging will not cause short circuit or deterioration of the negative electrode Lithium dendrite appears, which is not possible with graphite anodes. It can be quickly charged and discharged in a wide range of environments, and is suitable for automotive applications.
5, self-discharge small: the positive electrode uses conventional lithium manganate, the negative electrode uses lithium titanate battery, 60-degree storage 28-day capacity remaining rate of 88%, capacity recovery rate of 95% or more.
Disadvantages of lithium titanate battery
1. The energy density of other types of lithium-ion power batteries will be lower.
2, the problem of flatulence has been hindering the application of lithium titanate batteries.
3. Relatively high prices for other types of lithium-ion power batteries.
4. There is still a difference in battery consistency. As the number of charge and discharge times increases, the difference in battery consistency will gradually increase.
Lithium titanate battery application prospects
Lithium titanate negative lithium ion batteries will be developed in the following areas:
(1) Substituting zinc-manganese and alkaline-manganese primary batteries to save wealth for the society;
(2) Substituting nickel-cadmium and nickel-hydrogen small secondary batteries for durability;
(3) Electric bicycles and electric motorcycle power batteries;
(4) Replace 5 ampere-hour nickel-metal hydride batteries for HEV vehicles;
(5) Light-duty special vehicles and small commuting vehicles;
(6) Household and grid storage energy.