Lithium
Lithium-carbon dioxide batteries are attractive energy storage systems because they have a specific energy density that is more than seven times greater than commonly used lithium-ion batteries. Until now, however, scientists have not been able to develop a fully rechargeable prototype, despite their potential to store more energy.
Researchers at the University of Illinois at Chicago were the first to show that lithium-carbon dioxide batteries can be designed to operate in a fully rechargeable manner, and they have successfully tested a lithium-carbon dioxide battery prototype running up to 500 consecutive cycles of charge/recharge processes
Using Light to Recharge Lithium-Ion Batteries Twice As Fast
Exposing cathodes to light decreases charge time by a factor of two in lithium-ion batteries.
https://www.sciencenews.org/all-stories
The new 'gold rush' for green lithium
https://www.bbc.com/future/article/20201124-how-geothermal-lithium-could-revolutionise-green-energy
Cornwall, 1864. A hot spring is discovered nearly 450m (1,485ft) below ground in the Wheal Clifford, a copper mine just outside the mining town of Redruth. Glass bottles are immersed to their necks in its bubbling waters, carefully sealed and sent off for testing. The result is the discovery of so great a quantity of lithium – eight or 10 times as much per gallon as had been found in any hot spring previously analysed – that scientists suspect “it may prove of great commercial value”.
But 19th-Century England had little need for the element, and this 122C (252F) lithium-rich water continued boiling away in the dark for more than 150 years.
Fast forward to autumn 2020, and a site nearby the Wheal Clifford in Cornwall has been confirmed as having some of the world’s highest grades of lithium in geothermal waters. The commercial use for lithium in the 21st Century could not be clearer. It is found not only inside smart phones and laptops, but is now vital to the clean energy transition, for the batteries that power electric vehicles and store energy so renewable power can be released steadily and reliably.
Lithium is currently sourced mainly from hard rock mines, such as those in Australia, or underground brine reservoirs below the surface of dried lake beds, mostly in Chile and Argentina. Hard rock mining – where the mineral is extracted from open pit mines and then roasted using fossil fuels – leaves scars in the landscape, requires a large amount of water and releases 15 tonnes of CO2 for every tonne of lithium, according to an analysis of the whole lithium production process by raw materials experts Minviro. The other conventional option, extracting lithium from underground reservoirs, relies on even more water to extract the lithium – and it takes place in typically very water-scarce parts of the world, leading to indigenous communities questioning their sustainability.
Extracting lithium from geothermal waters – found not just in Cornwall, but Germany and the US as well – has a tiny environmental footprint in comparison, including very low carbon emissions.
Company claims solid-state lithium-metal battery breakthrough
All modern lithium-ion batteries are, in a way, a compromise. The original concept was a “lithium metal” battery, which could hold substantially more energy in the same volume. There was just one small problem: they invariably self-destruct. But this week, a long-watched battery-tech company announced that it believes to have solved this problem. If what the company shows is accurate, this is a big deal.
The solution was to utilize a graphite anode. The orderly structure of graphite makes a good hotel for lithium ions, which safely check into a room for their stay during charging. This greatly reduces the risk of dendrite formation. But this graphite can take up nearly half the volume of the cell without adding additional energy storage. This makes the battery work safely but dilutes its performance.
One strategy that has been pursued to improve lithium-ion batteries is the creation of a solid electrolyte material. That’s attractive because it replaces the flammable component of the battery and also because it could reduce unwanted chemical reactions between the electrolyte and other battery materials that cause degradation over time. QuantumScape has been working on a solid electrolyte for around a decade, after the project spun off from a Stanford lab and received some funding from the US Department of Energy. (Although the company started with a different technology that didn’t pan out.) But in addition to these benefits, QuantumScape says its solid electrolyte material also prevents dendrites from forming.