Splitting Water

Many engineers will tell you that hydrogen isn't a fuel so much as an energy carrier. That is, hydrogen is usually produced with a process that requires an energy input of some sort. Reducing the energy needed to make hydrogen would cut its costs and improve its net energy balance. 

Most of the world's hydrogen gas is produced from fossil fuels, like methane. Scientists recently developed a catalyst that can better produce hydrogen from water. The new material requires less energy, making water a more viable option for producing hydrogen.

Finally getting it right with lithium ion

Researchers recently figured out that some of their models of lithium ion batteries were based on flawed assumptions. The old model used experimental results, but assumed that battery performance is governed by lithium ion movement between electrodes. The new findings show that it's actually electron movement that's the rate-limiting step, so scientists switched to a new model.