Lithium-titanate (LiTi) is a new generation of lithium-ion battery, which uses lithium titanium oxide (Li 4 Ti 5 O 12) instead of graphite as the anode material. Fast charging is considered as the most attractive feature of lithium-titanate battery, although it has a relatively lower cell voltage compared with other lithium-ion batteries.
Using Li4Ti5O12 as its anode instead of graphite, the lithium titanate battery has the inherent advantages in rate characteristics, cycle life and chemical stability, which is more suitable for rail transit application. As an indicator of battery available energy, state of energy (SOE) is of great importance to estimate.
This paper investigates the characteristics of lithium titanate batteries at normal temperature in storage field. It has been reported that lithium-ion batteries ages faster at high state of charge (SOC) , so the batteries were charged 100%SOC before storage.
Lithium titanate material known as zero-strain material has a spinel structure, cell volume of which will shrink after multiple cycles. In addition, lithium titanate battery doesn’t have solid electrolyte interphase (SEI), which avoids capacity fade and thus, has a longer life as a result.
Two batteries nominal capacity are both 8.5Ah. After storage, actual capacities of two batteries are both more than 8.5Ah and capacity loss is not obvious during storage. Combined with results of Table.2, it can be noted that lithium titanate battery capacity loss is caused due to self-discharge.
A disadvantage of lithium-titanate batteries is their lower inherent voltage (2.4 V), which leads to a lower specific energy (about 30–110 Wh/kg ) than conventional lithium-ion battery technologies, which have an inherent voltage of 3.7 V. Some lithium-titanate batteries, however, have an volumetric energy density of up to 177 Wh/L.
A lithium-titanate battery is a modified lithium-ion battery that uses lithium-titanate nanocrystals, instead of carbon, on the surface of its anode. This gives the anode a surface area of about 100 square meters per gram, compared with 3 square meters per gram for carbon, allowing electrons to enter and leave the anode quickly. Also, the redox potential of Li+ intercalation into titanium oxides is more positive than that of Li+ intercalation into graphite. This leads to fast charging (hi…