Sunday, February 22, 2009

PHEV and Li-ion Batteries: Environmental Consequences of Mass Production

Many people would agree that plug-in hybrid (PHEV) and electric (EV) vehicles are the next big shift in the auto industry. They are certainly an attractive alternative to traditional automobiles, and have caught the eye of environmentalists and politicians alike. However, advancements in storage, weight, and cost of batteries are needed before these vehicles can truly be marketable. Lithium-ion batteries may hold the solution to the energy storage problem, and are already widely used in the portable electronics industry. Currently, lithium-ion batteries are also the preferred battery type by a handful of companies developing PHEV and EV systems. In 2010, General Motors expects to release two PHEV models that use lithium-ion batteries [1].

Lithium is extracted from deposits beneath brine pools, sometimes called “salt flats” [2]. According to the Handbook of Lithium and Natural Calcium, “lithium is a comparatively rare element…always in very low concentrations…[and] only comparatively a few of [the deposits] are of actual or potential commercial value” [3]. Like oil, lithium is a limited commodity and the same economic and political principals should apply. Unfortunately, this fact has gone largely overlooked, overshadowed by the enthusiasm for these “green cars.” Where we get our source of lithium and the environmental, political, and social impacts caused by a large increase in its demand are important policy issues that future PHEV and EV manufacturers will have to face.

In 2008, Meridian International Research conducted a study of the world’s existing and future lithium resources and what that means for the future market of PHEV and EV vehicles. The study resulted in four main conclusions. First, anticipated demands for lithium, from the PHEV and EV markets as well as the growing portable electronics industry, far exceed the existing and future reserves. Secondly, these recoverable reserves are significantly lower than previously estimated. Thirdly, substantial damage to the ecosystem will result from the mass production of lithium. And lastly, production of lithium will worsen the U.S.’s already strained relationship with Latin America, where the vast majority of lithium resources are located [3]. A recent NY Times article highlights the political concerns effecting future lithium production, calling Bolivia, home to half of the world’s lithium deposits, the “Saudi Arabia of lithium” [2].

While the availability and future demand for lithium can only be speculated, more research should be done into less harmful methods for lithium extraction and production. Similarly, more R&D dollars could be spent on improving other types of batteries that aren’t dependent on non-renewable resources. In fact, improving energy storage is also essential to making renewable energy technologies like solar and wind competitive with conventional technologies. Batteries that can store energy from the sun and wind, to be dispatched to the grid during peak demand, are critical if solar and wind technologies are ever going to surpass fossil fuels for power generation. The need for improved energy storage will only grow from here, and a sustainable source will need to be discovered. And while it’s easy to get caught up in the excitement of renewable energies and “green cars,” we cannot disregard the need for a comprehensive analysis of the long-term costs of their mass production.



Mithun said...

So many people believe that PHEV is such a good idea, still why is it that, we dont see so many of them ? It is said that, we had an EHV program in this country in 1976, its been 31 years since we were aware of this technology, then what are the major roadblocks in getting the EHV on the streets. Its the battery and their associated high costs. At times, battery costs exceed the the cost of the car itself. In case of Li-ion there are a few technical problems. Li-ion batteries are high on energy but low on power, it means that Li-ion are unable to provide huge bursts of energy in short time (power) resulting in lower acceleration. Their life spans are short. For a car a battery life span of atleast 8-10 years is expected, while they have a lifespan of 2-3 years. There are safety issues too with Li-ion batteries. Li-ion battery disposal is another issue. Keeping all this in mind, we have to improve our technology in battery production and move on from Li-ion to more advanced battery technology to address the technical and cost problems associated with Li-ion batteries.

Windy said...

This is a good article that points out a very important issue. Before we put all of eggs in one basket (in terms of policy decisions, research and development, etc.) we should take steps to ensure that our future plans are, in fact, sustainable.

I think that PHEVs and EVs can and should play a large role in our future. I think the technical issues with batteries could be greatly reduced with increased research and development. However, as the blog pointed out, concerns regarding the availability of the batteries, environmental impacts associated with mining the lithium, and potential political issues are going to be more difficult to handle.

My question then, is do we have other options? If our current gas-guzzlers are too dirty and expensive to drive and our future hope for battery-operated vehicles are dashed, what can we turn to? (In terms of personal transportation—mass transit is an obvious answer, but that is a topic unto itself).

A quick Google search turned up a couple interesting options. An article by Joseph Ogando in Design News ( explained the concept of a hydraulic hybrid vehicle. These cars and trucks are similar to battery-powered hybrids with one major difference—no battery. Instead, energy is stored in high-pressure hydraulic accumulators. The article noted that these vehicles could double gas mileage, reduce emissions by 50% and that they would actually get better gas mileage in the city than on the highway.

This technology is currently being tested in big vehicles (like UPS and FedEx trucks). More information can be found on the EPA’s website (

Another article from Popular Mechanics ( discussed the idea of replacing lithium-ion batteries with ultracapcitors. Researchers at MIT are working to find ways to do just that. Although the technology is years away from mass production, it holds promise.