RS2E Network Researchers Develop First Sodium-Ion Battery In 18650 Format

The first sodium-ion battery in an 18650 format was recently developed by researchers in the RS2E network (Réseau sur le stockage électrochimique de l’énergie) in France, according to recent reports.

The new sodium-ion (Na-ion) battery prototype possesses an energy density of 90 Wh/kilogram — putting it on roughly equal ground with early lithium-ion batteries. The lifespan of the prototype is higher than 2,000 charge-discharge cycles, though, and sodium is cheaper than lithium of course.

Also worth noting, is that the prototype possesses rapid charge and delivery rates.

The press release, emailed to EV Obsession, stated:

The first step was to find the ideal “recipe” for the positive electrode (cathode) of the battery. Six partner laboratories of the RS2E (see list below) were involved in the project with the goal to find the right composition for this sodium electrode. The development of a future prototype was then entrusted to CEA, a member of the RS2E network. In only six months, CEA was able to develop the first sodium-ion prototype in the “18650” format, that of the batteries found on the market, i.e. a cylinder 1.8cm in diameter and 6.5cm in height. This should facilitate technology transfer to existing production units. Other international laboratories also work on this technology, but none of them has yet announced the development of such a “18650” prototype.

This second stage made it possible to move from the laboratory scale (synthesis of several grams of cathode material) to the “pre-industrial” scale (synthesis of 1kg batches). It enabled the production of batteries with unmatched power performance levels. This new technology is already showing promising results. Its energy density (the quantity of electricity that can be stored by Kg of battery) amounts to 90Wh/kg, a figure already comparable with the first lithium-ion batteries. And its lifespan—the maximum number of charge/discharge cycles that a battery can withstand without any significant loss of performance—exceeds 2,000 cycles. But most of all, these cells are capable of charging and delivering their energy very rapidly. The main advantage of the technology is that it does away with lithium, a rare element only found in specific locations, contrary to sodium. Its other advantage is financial, as using sodium could make it possible to manufacture less expensive batteries.

The project has given rise to a number of CNRS and CEA academic publications and patents. It received financial support from the French Ministry of Higher Education and Research, the CNRS, CEA, the French National Research Agency (ANR) and the Ministry of Defence’s Armament Directorate (DGA), among others.

The researchers involved are now working to improve reliability, and pave the way to commercialization and, presumably, to a wide rollout where application of the technology makes sense. At this point, the exact circumstances where the technology will immediately make sense aren’t yet clear.

Image Credit: RS2E