When FMC (NYSE: FMC) came out with stellar numbers some days back, it took my focus back to a metal that has a lot of practical uses but hasn't caught much attention yet. Lithium, a lightweight silvery metal, has made our lives easier in more ways than we may know. For instance, nearly 90% of laptops and 60% of mobile phones are powered by lithium-ion batteries today.

However, the biggest potential for lithium lies in electric cars. High-energy storage and long-lasting traits of lithium batteries are attracting more automakers now. And there is speculation about a possible change of the long-wait tax credits an electric/hybrid vehicle buyer currently gets into quick rebates. If legislators approve the proposal, lithium-ion battery makers and lithium producers may be in line for some rewards.

The lithium story could indeed be a big money maker in the long run, and you can get into it by considering individual stocks of companies that are in the lithium business. But is there a way to get exposure to all at once? Yes. Consider an exchange-traded fund. Take a look at the Global X Lithium ETF (NYSE: LIT), which gives you exposure to most of the big lithium plays with lower risk and lower cost. (Click here to read more about ETFs).

Diverse yet focused exposure
Global X Lithium tracks the Solactive Global Lithium Index, made up of companies that are into lithium mining or exploration or are producers of lithium batteries. The fund currently offers exposure to 20 companies, and has a good mix of both lithium producers and battery makers. Nearly 42% is allocated to the U.S.

Here's a quick look at the top three holdings as of Feb. 14:

  • Sociedad Quimica y Minera (NYSE: SQM)  -- Being the world's largest lithium producer, with huge reserves in Chile, Sociedad is the most important company in the fund's holdings, constituting 19%. The company has been performing well, with revenue and net income climbing at a compounded rate of 23.4% and 38.7 %, respectively in the past 12 months. Sociedad's shares have risen around 10% since the beginning of this year.
  • FMC -- This chemical maker constitutes 17.1% of the fund's holdings. Although FMC is not a pure lithium play, it is nevertheless trying to take full advantage of the lithium run as the metal is playing a critical role in driving up its revenue. FMC is expanding capacity of its lithium facility in Argentina by 30%, and has plans for more. It has also shown interest in putting a foot in Chile after the world's largest lithium supplier announced auctioning of lithium mining contracts to new companies. If FMC decides to enter Chile, it is most likely to boost its share price. The company's top line and bottom line have grown at a compounded rate of 8.4% and 112.1%, respectively, in the past year. FMC's shares have climbed around 14% since the beginning of this year.
  • Rockwood Holdings (NYSE: ROC) -- Rockwood forms 9.95% of the fund's holdings. The company is directing a major chunk of its investments toward lithium now. New plants in North Carolina and Germany are already under way, and Rockwood has also unveiled plans for a new plant in Chile to double lithium production. In the past year, Rockwood's revenue and net income have grown at a compounded rate of 22.4% and a staggering 225.7% (a good part of which was due to earnings from discontinued operations), respectively. Rockwood's shares have gained a phenomenal 33% since the beginning of January.

Among battery producers, names like A123 Systems, Exide Technologies, Ener1 and SANYO Electric feature in the fund's top holdings.

The Foolish bottom line
With the global consumer battery market projected to explode in the next five years, betting on this great alternative to fossil fuels could turn out to be a smart move. Global X Lithium's expense ratio is 0.75%, which is on the higher end of the spectrum, but the ETF continues to deliver good performance. The fund is up nearly 13% since Jan. 1, and any dip could be a good opportunity to make way for lithium in your portfolio. Let me know what you think using the comments section below.

Interested in an easy way to track Global X Lithium? Add it to your watchlist. And if you want more great ETF ideas, we've got three more that you shouldn't miss. Read our free special report to get our list of ETFs that should soar in the recovery.