With the rise of the lithium-based battery, demand for this soft, silvery-white metal – the lightest solid element in the periodic table – has exploded. With the race to zero carbon by 2050 gathering steam, forcing the electrification of transport, lithium will be an even more valuable asset in the next 30 years.

The supply of raw materials for batteries could even end up being a national security issue, too; China’s global leadership on high-volume EV production has put it ahead of the game, and while the majority of ground-based lithium reserves are in the “lithium triangle” of Chile, Bolivia and Argentina, China controls more than half’s the world’s supply simply through investments and ownership. It has shown in the past that it’s not afraid to wield commodity supplies as a weapon.

But as with other metals like uranium, land-based lithium reserves pale in comparison to what’s out there in the sea. According to researchers at Saudi Arabia’s King Abdullah University of Science and Technology (KAUST), there’s about 5000 times as much lithium in the oceans as there is in land deposits, and a newly developed technology could start extracting it cheaply enough to make the big time – while producing hydrogen gas, chorine gas and desalinated water as a bonus.

Scientists in South Korea have made a breakthrough in battery research that could help us bust through a key bottleneck in energy storage. The team’s advance overcomes a technical issue that has held back highly promising lithium-metal battery architecture and could pave the way for batteries with as much as 10 times the capacity of today’s devices.

The reason lithium-metal batteries hold so much promise is because of the excellent energy density of pure lithium metal. Scientists hope to swap out the graphite used for the anode in today’s lithium batteries for this “dream material,” though this comes with some complicated problems to solve.

One of the key issues relates to needle-like structures called dendrites, which form on the anode surface as the battery is charged. These penetrate the barrier between the anode and the battery’s other electrode, the cathode, and quickly cause the battery to short-circuit, fail, or even catch fire.

The researchers started with a sample taken from the temporal lobe of a human cerebral cortex, measuring just 1 mm³. This was stained for visual clarity, coated in resin to preserve it, and then cut into about 5300 slices each about 30 nanometers (nm) thick. These were then imaged using a scanning electron microscope, with a resolution down to 4 nm. That created 225 million two-dimensional images, which were then stitched back together into one 3D volume.

Machine learning algorithms scanned the sample to identify the different cells and structures within. After a few passes by different automated systems, human eyes “proofread” some of the cells to ensure the algorithms were correctly identifying them.

The end result, which Google calls the H01 dataset, is one of the most comprehensive maps of the human brain ever compiled. It contains 50000 cells and 130 million synapses, as well as smaller segments of the cells such axons, dendrites, myelin and cilia. But perhaps the most stunning statistic is that the whole thing takes up 1.4 petabytes of data – that’s more than a million gigabytes.