Sodium-sulphur molten salt battery promises much better performance

Previous molten salt batteries use aluminium-sulphur compounds and generally have a low energy density and require high temperatures to keep the salt molten, making them quite unusable. This new development, however, instead uses a unique sodium sulphur compound and room temperature molten salt, making it much more usable, cheaper and environmentally friendly than other molten salt batteries. To test this, the researchers created a prototype button cell and put it to the test, and what they found was remarkable.

Firstly, this battery was incredibly energy dense at 1017 mAh/g. For comparison, high energy density lithium-ion batteries have an energy density of about 250 mAh/g, which means this battery can do four times more than that!

However, there is no data on how much such a device would cost. However, it is estimated that another battery using more expensive materials, such as molten salt, would cost around $15/kWh. By comparison, current lithium-ion batteries cost roughly $132/kWh. Assuming, therefore, that this new molten salt battery would be similarly priced, it would be about 90 percent cheaper than current cells.

Since this new molten salt battery operates at room temperature, it could theoretically be used in Evtol. All that would be needed is a small secondary battery to power the heater in cold weather.

So this would be the ultimate EV battery ? If these were used then four times the capacity could be incorporated without increasing weight. In addition, this mega battery pack would cost less. In other words, using this battery would make EVs almost perfect.

However, there is a catch. In fact, tests of the battery have shown that after 1000 charge cycles, its capacity has dropped by 50 percent. For more affordable vehicles that use smaller packs, this level of degradation would result in a life cycle too short to be viable. Since this was a test cell, it was not designed for long life, so it’s actually surprisingly good. This also means that future versions of this cell could be further refined and improved to last much longer.

But as things stand, this terrifically cheap and environmentally friendly cell is much more suited to being used as a storage battery for the renewable energy grid. Its safe nature and super-low price amply compensate for its short lifespan. Moreover, as this battery is built from readily available materials, it can be used to rapidly expand grid storage capacity without supply chain problems or the price of EV batteries skyrocketing as supply cannot keep up with demand.

Therefore, researchers are now developing a larger-sized battery cell version (like those used to power phones and laptops) and could work specifically in such devices.

Source: onlinelibrary.wiley.com