How Lithium Titanate Batteries Work
Lithium titanate (LTO) based batteries rely on a promising new technology that employs nanostructured materials to improve the performance, quality, and lifetime of these batteries.
The battery consists of the three main parts: an anode, a cathode, and electrolyte solution. However, the anode in these batteries is covered with nano-structured lithium-titanate instead of carbon (in the case of Li-ion batteries). This new technology increases the electrode's active surface area and allows electrical charges to move more easily and quickly. The high currents can then provide fast charging and discharging rates, long cycle life, and the ability to withstand diverse environmental and temperature conditions.
Lithium Titanate vs. Lithium-Ion Batteries
Listed below are the main advantages of LTOs compared to the conventional Li-ion batteries:
- Li-ion batteries generate power by allowing lithium ions to pass from the lithium cobalt oxide made cathode to the carbon made anode through the electrolyte solution of the battery. As described above, the anode of the lithium titanate battery is covered with lithium titanate nanocrystals that are chemically enhanced in order to provide a larger surface area (100 m2/gram compared to the 3m2/gram for carbon). This allows greater charge and discharge rates and an increase in energy storage. These batteries can be recharged in 10 minutes roughly, while conventional batteries demand hours.
- The lack of carbon in the anode of the LTOs eliminates any overheating problems making the battery safer to use.
- Conventional Li-ion batteries can be recharged approximately 1,000 times. The total number of recharges for a lithium-titanate battery range between 15,000 to 25,000 times, as was demonstrated in Altairnano's labs.
- LTOs are suitable for low temperature environments and can also endure high temperature more effectively (-40°C to 55°C).
However, LTOs have some drawbacks including the low voltage (2.5V vs. LiCoO2 and 1.9V vs. LFP) and still low capacity compared to their lithium-ion counterparts. They also have low power density, although Altairnano claims to have achieved a much higher power density than the conventional Li-ion batteries (power per unit weight: 4000 W/Kg and power unit volume over 7,500 W/litre).
High Application Potential and Current Status for Lithium Titanate Batteries
The two leading companies in lithium titanate battery technology are Altairnano and Toshiba.
Altairnano announced the breakthrough of nano-structured lithium titanate battery technology in February 2005. They used this material to replace the carbon in conventional lithium-ion batteries and achieved better performance and a high potential for various energy storage applications.
Altairnano developed a series of lithium-titanate batteries for electric vehicle use and many electric-vehicle manufacturers announced their intention to use this new battery technology; the list includes Lightning Car Company, Phoenix Motorcars, Protera, etc. They are also currently collaborating with the US Navy in order to incorporate the new battery technology in Navy equipment. Finally, they have deployed these new energy storage systems for electric grid ancillary services as well.
Toshiba is the second leading company in the field. After having developed their own lithium-titanate battery, they dubbed it the "Super Charge Ion Battery," or SCiB. It is designed to offer 90% charge capacity in 10 minutes. They intend to use them as laptop batteries and also plan to use their SCiB for powering electric cars and bikes.
Currently, Toshiba is investing in a $279 million additional lithium titanate production facility in order to increase production. They estimate to reach $2.2 billion in sales by 2015.
Analysts speculate that LTO-based batteries will dominate the market of electric vehicles in the near future. Companies such as Toshiba have started investing enormous amounts of money on this new technology. Vehicle manufacturers are seeking to invest in lithium titanate batteries in order to improve their vehicles performance. It is very likely that Lithium Titanate batteries will revolutionize the market the way Li-ion batteries did.
- "Altairnano Wins 10MW Lithium-Titanate Battery Project", ElectroIQ
- "Lithium Titanate Based Batteries for High Applications High Rate and High Cycle Life Applications", Nei Corporation
- "Lithium Titanate Battery – Charge 18,000 Times" by prlog.org
- "Toshiba Looking to Supply Lithium Titanate EV Batteries to 5 Automakers" , allcarselectric.com
Conventional Lithium Ion Battery by commons.wikimedia.org