What’s In Store For Next-Generation Hybrids

Recent decades have seen almost symbiotic advances in the capabilities of portable consumer electronic devices and the batteries that power them.

As laptop computers, PDAs, mp3 players and other electronic devices have entered the market, their energy requirements have driven an evolution in battery technology. Those advances have enabled not only longer operation, but enhanced functionality, which in turn has frequently led equipment manufacturers to demand yet further battery improvements. 

Remembering the Past

Think about cell phones. In the mid-80s, early adopters had to carry around a lead-acid battery (PbA) that looked a little like a small briefcase and could weigh more than ten pounds. Imagine lugging that as you run errands around town. 

Today’s cell phones, in contrast, are powered by lithium-ion batteries that permit as much if not more talk time, support cameras, Internet access, and a multitude of other features at a fraction of the weight.   

If these developments are any sign, we may soon see a revolution in higher-voltage batteries—ideal for powering cars and light trucks. The success of hybrid electric vehicles over the past few years has motivated substantial research into batteries that are relatively lightweight, pack a lot of punch, and are safe for the road.

The Current Technology

Hybrid electric vehicles (HEVs) for sale today come with nickel metal hydride (NiMH) batteries. These batteries have better energy density (i.e., lighter weight) than their PbA cousins (the kind of starting battery you find in non-hybrid cars) and can last for more than 500 full discharge cycles.
 

The benefit of hybrid-electric drivetrains is that they seldom drain the battery entirely. Instead, they use a “shallow” cycle for pulsing the vehicle in its various acceleration modes. Engineers at Toyota, Ford and other car manufactures believe this technology will allow NiMH batteries to last for far more than a few hundred cycles—somewhere between six and ten years, depending on how the car is driven.
 

By those calculations, the battery needs replacing only once during the life of the car. Many manufacturers cover the battery under warranty—so you needn’t worry about getting stiffed with a few thousand-dollar repair bill later if you plan to hold on to your HEV into its later years. However, this is new warranty territory and the business models are built on speculation.
 

Manufacturers have a real incentive to recycle these batteries when they do need replacing, since the materials they contain are valuable. (In fact, car batteries in general are one of the lesser-known recycling success stories in the U.S. -- over 95 percent of PbA car batteries are diverted from the landfill each year.) Should HEVs one day carry lithium-ion batteries, there will most likely be a large market for deconstructing and reclaiming their components. Some companies, like Umicore, are already establishing facilities to recycle lithium-ion batteries in a sustainable, green fashion.  

The Cost of Innovation
 

One major hurdle to bringing this advanced battery technology to market, however, is cost. Historically, most companies have failed in bringing new energy storage technologies to market due to the exorbitant investment associated with ramping up research and development (R&D) results to full-scale production. On average, bringing a radically new energy storage technology to market is a $100 million, 10-year adventure that only the well-funded survive.

 
The good news is that the ever-growing need for improved battery capabilities has spurred unprecedented investment in battery research. (Car manufacturers would love to increase the battery life from between six and ten years to fifteen years or more. That would eliminate the need to replace the battery over the life of the car, saving the companies money.) Despite the costs, there is some evidence that recent development activity in energy storage is beginning to bear fruit.

What the Future Holds

 
If the future in transportation solutions repeats the recent history in consumer electronics, then lithium-based batteries will eventually dominate the market.
 

However, the demands on energy storage from transportation and stationary applications are so severe that familiar and trusted energy storage solutions using PbA and NiMH batteries might maintain their current niche for some time.
 

In my opinion, these niche markets will be temporary as a large-format lithium-based battery is developed, proven, and ramped up to high-volume production, allowing an affordable energy storage solution that has little competition. 

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John Waters heads the Plug-in Hybrid Electric Vehicle (PHEV) Team at the Rocky Mountain Institute. He is an engineer and business development professional with 20 years' experience in product design, strategic planning, and production of engineered products and solutions. He has taken the lead of RMI’s newest team to develop a practical and profitable Plug-in Hybrid Electric Vehicle and an associated vehicle-to-grid strategy.