Redefining Energy Storage in Transportation Markets:
The Lithium Revolution

Anu Elizabeth Cherian, Industry Analyst
Frost & Sullivan

Almost two decades ago, North America was the leading oil user in the world, especially in light of the automotive market. Light and heavy vehicles alike required a lavish supply of oil for performance, features and the ultimate driving experience. As the political relationships between different continents has significantly influenced the price and supply of natural gas, there is an increasing need among the global gas consumers to look for more efficient and successful alternatives to sustain industrial growth while preserving earth’s natural resources and refraining from the exploitation of its rich treasures.

Reminiscing on the evolution of the energy storage market from lead acid to lithium ion brings credibility to the future direction this market is likely to take. Lithium has been around since the 1800s, but its potential in energy storage mechanisms was discovered more than a century and a half later. Lithium was identified as a very good anode material for batteries in the 1970s. When lithium is placed as a metal at the anode, there is a serious safety hazard involved. The groundbreaking discovery and the combination of the use of graphite anode and a workable cathode, were officially launched by Sony in 1991. After almost two decades, our experience with the many benefits of the lithium-ion battery has only become better.

The third decade holds high expectations. This battery type is expected to leverage and revolutionize the transportation market in providing efficient energy storage mechanisms, thereby reducing the amount of gas used in the combustion engine. Currently, there are several types of lithium-ion chemistries that exist in the market, such as lithium manganese, lithium titaniate and lithium phosphate, among others.

Hybrids
Hybrid electric vehicles (HEVs) and electric vehicles (EVs) are a few of the applications in which lithium-ion batteries are expected to create a spur in the market. HEVs are widely used in North America. Nearly 15 different types of HEVs manufactured by major automotive manufacturers are projected to be launched in 2009. Along with an increased focus on newer vehicle technologies, the core energy storage mechanism also projects to display a dynamic shift of focus.

The traditional nickel metal hydride (NiMH) chemistry currently powers all HEVs. However, there are great expectations from the lithium-ion chemistry to be a viable and winning competitor to the NiMH battery. Several prototypes were on display at all global auto shows, displaying newer additions such as the lithium-ion and the ultracapacitor. The HEVs and EVs powered by this chemistry are undergoing vigorous testing and modifications to tailor to the needs of the highly cost-conscious end user.

HEVs utilize the features of a conventional engine as well as a battery, reducing its dependence on both. The features required for HEV/EV batteries that make it desirable are high energy density, high specific power, long shelf life, less maintenance, lightweight, compact size, quick charge and discharge capabilities and competitive price.

Many major automotive manufacturers have entered an alliance or a multi-year contract with Li-ion battery manufacturers to develop Li-ion batteries suitable for HEV/EVs. These automotive manufacturers have started testing their HEV/EVs using Li-ion batteries and are expected to launch Li-ion powered HEVs and EVs by the end of 2009.

Automotive Partnerships with Lithium-ion Battery Manufacturers
• Toyota is closely working with Matsushita Electric Industrial and Panasonic EV Energy, which recently acquired Sanyo to build its Prius’s and other concept cars.
• Volkswagen relies on Panasonic for its hybrids with the Audi brand while working with Toshiba for its electric vehicles.
• Daimler is working with JV Company and Evonik to develop its electric vehicle
• GM, now owned by the government, is working with LG Chem on its Chevy Volt while its subsidiary Saturn associates with Hitachi Vehicle Energy Ltd., a combined partnership with Hitachi and Shin-Kobe Electric Machinery.
• Mitsubishi is working with its parent company along with GS Yuasa and Lithium Energy Japan.
• Ford and Daimler are also in a consortium with BYD in sponsoring research on battery technology with Johnson Controls-Saft.
• Tata Motors from India is working closely with Electrovaya to create a revolution in the electric vehicle market just as they accomplished with the Nano.

The Tesla Roadster
The car that has gained significant attention in the past year has been the Tesla Roadster. Initially slated for production in October 2007, the production did not go live until March 2008. The Tesla Roadster is based on the Lotus Elise and is powered by 6,831 lithium-ion cells with 248 hp output. The basic chassis design is from Lotus Cars and it shares less than 10 percent of its components from the Lotus Elise. The light weight of this car is maintained by the RTM carbon fiber body panels, the only one of its kind provided by the French company SOTIRA.

The end of 2008 saw the delivery of the first 100 Tesla Roadsters. However, the first quarter of 2009 witnessed more than double that number in sales, despite the high price premium placed on this car. The car produced in the model year 2008 was sold at a price of $100,000 while the 2009 model starts at a base price of $109,000 due to the improvements made in the transmission reliability. The significant feature of this car is the achievement of 0 to 60 mph in four seconds powered by the lithium battery. The distance traveled between batteries charges averaged at 227 miles.

The Energy Storage System
The Energy Storage System or ESS, is the combination of innovation and technology to sustain the heart of a car such as the Roadster. The cells used in the Tesla Roadster are called 18650 based on its individual dimensions, 18 mm diameter by 65 mm length. The basic intent is to have a smaller cell so that the impact of a failure from a single such cell will be lesser than a cell many times larger. The total weight of the energy storage unit alone is 450 kg.

Arranged similar to the laptop batteries, the 6,831 lithium-ion cells are placed in 11 sheets in series. However, a brick of 69 cells is connected in such a way that failure in one cell will not affect neighboring cells. This is highly essential for the safety of the car, especially while it is moving and there are ample opportunities to spark a fire. It is the safety aspect of the lithium-ion which is a great concern among end users. Nevertheless, essential safety measures have been devised in the Tesla Roadster to protect from all possible disasters.

Safety Measures
• It has an internal positive temperature co-efficient (PTC) current limiting device. It limits short circuit in individual cells.
• At the individual cell level, a Current Interrupt Device (CID) is present that protects each cell from excess internal pressure.
• Packaging of cells is done in steel cans, providing strength to the battery unit. Steel also offers good thermal conductivity thus extending the life of the battery in addition to dissipating excess heat from causing sparks in the material of the battery.
• The battery pack is enclosed with aluminum as opposed to plastic used for laptops. Aluminum has excellent ability to withstand heat.
There are several other features incorporated into the design of each battery on a micro-level to ensure the ultimate in safety and abuse protection.

A recent and very significant development is the equity position that Daimler AG has taken in Tesla Motors to propel and significantly accelerate the commercialization of the lithium-ion battery. This is in addition to the relationship with Evonik, and an interim arrangement until Evonik has its batteries ready for the electric vehicle.

The Issue of Material Shortages
A question that arises is the availability of lithium and its ability to sustain growth in the batteries market, especially in a high demand transportation sector. The answer is fairly unclear right now; however, the following facts remain.
• Lithium is the 35th most abundant element on the planet.
• Raw material prices overall have been extremely volatile over 2008 and continue to remain unsteady in 2009 as a result of
the economic situation.
• Lead and steel in particular, have witnessed several deficiencies in supply and, as a result, prices began to increase.

However, with the already commercialized Tesla and upcoming models by the end of 2009, the issue on the availability of lithium and its extraction and use is another issue that needs to be addressed at large, before getting too comfortable with the technology.

The Future of Lithium is at Hand
As we stand on the threshold of the third decade of lithium-ion batteries and their revolutionary role in powering our lives, the journey begins in the transportation world. Although the keys have unlocked the technology, there are several holes to fill, such as more power in a smaller size and weight of the battery. However, the two most important tests the automotive lithium-ion battery must take from an end-user perspective is cost and safety for its road suitability. Its proven record in these two areas will increase confidence and bring us closer to the use of lithium over natural gas.

For more information regarding this article, please contact Johanna Haynes at johanna.haynes@frost.com.

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