Crystal grains can hold huge amounts of oxygen for lighter underwater breathing

Researchers from the University of Southern Denmark have synthesized crystalline materials that can bind and store oxygen in high concentrations.The stored oxygen can be released again when and where it is needed.
We do fine with the 21 per cent oxygen in the air around us. But sometimes we need oxygen in higher concentrations; for example lung patients must carry heavy oxygen tanks, cars using fuel cells need a regulated oxygen supply. Perhaps one day in the future even sunlight-driven “reversible” fuel cells will be made. With these we will have to separate oxygen from hydrogen in order to recombine them in order to get energy.
A few grains contain enough oxygen for one breath, and as the material can absorb oxygen from the water around the diver and supply the diver with it, the diver will not need to bring more than these few grains. The new material is crystalline, and using x-ray diffraction the researchers have studied the arrangement of atoms inside the material when it was filled with oxygen, and when it was emptied of oxygen.