Today's a big day for those of us obsessed with battery tech, with two new technologies in the works which promise to increase capacity for power packs -- if they manage to make it to market.

Up first is a new spin on the traditional lithium battery, which uses sulfur as part of the cathode in the cell instead of the more traditional metal oxides used today. To solve a decades-old challenge, a nanoscale carbon structure is used to trap liquefied sulfur, keeping the sulfur in electrical contact in sufficient surface area to work as a component of the battery.

The upshot is that the new sulfur-based design can theoretically store three times the energy of a traditional lithium-ion battery of the same size. And since sulfur is in such abundance -- sulfur is a by-product of oil and gas production and the stuff piles up in small mountains outside many refineries -- there's certainly no worry that we'll run out of it in the foreseeable future. Patents have been filed.

Battery breakthrough #2 involves the use of technology that would allow batteries to be recharged by simple exposure to the air. Also using a carbon lattice like the lithium-sulfur cell described above, oxygen molecules are drawn from the air and become trapped in the matrix for use as part of the chemical reaction in the battery. When spent, the battery can draw in more oxygen, allowing a sort of natural recharging to occur as the battery operates and giving it a theoretical running time up to 10 times that of a non-air-based cell. And, because air is weightless, the battery cell is lighter than a typical chemical cell.

The so-called STAIR cell isn't as far along as the lithium-sulfur cell, and prototypes are still being developed. However, if all goes well, it could be a suitable battery for many applications ranging from cell phones to electric cars -- anywhere where reducing weight is of special concern.