How do Lithium Titanate
batteries work and are they really superior to conventional Lithium-ion
batteries? Are they going to substitute for their counterparts in the future
market?
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.
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).
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.