Quest goes on to create better batteries

At a cozy watering hole in Brooklyn's Bedford-Stuyvesant neighborhood, bartender Kathy Conway counted four different phone chargers behind the bar.

Call it the scourge of the red zone, call it battery anxiety. Smartphone users are tired of begging to charge devices behind bars or hunting for hidden electrical outlets in airports and train stations. Where, oh where, is a better battery?

The common lithium-ion battery that is used to power laptops, cellphones and tablets has improved in recent years. Battery capacity has tripled since 1990, says K.M. Abraham, a professor at Northeastern University who researches batteries.