French scientists have presented the first promising prototype of a sodium-ion battery, which will replace the now-popular lithium-ion batteries in the 18650 format. As the name implies, the base will be a sodium element, whose earth’s reserves are much larger than lithium, and it costs less . Scientists have managed to develop a battery of size 18650 (1.8 cm in diameter and 6.5 cm in length), in which sodium is used instead of lithium. The resulting copy was the next step leading the development from laboratory copies to a mass consumption product. The product already shows good test results. The energy density of the battery is 90Wh / kg, which is comparable to the parameters of the first lithium-ion batteries. In addition, the novelty is able to withstand more than two thousand charge / discharge cycles. Although lithium has several advantages – it is lighter than sodium and provides greater energy efficiency, the element itself is considered rare. While sodium is more affordable, its content in the earth’s crust is estimated at 2.6%. This means that the cost of batteries in the future can be significantly reduced. \. The team counts on successful tests and on the speedy launch of the product on the European consumption market.