The global demand for batteries is increasing. Already within the next 7 years, batteries will be in demand 14 times over, according to an estimate by the European Parliament (1). An estimate that makes one wonder whether and what the battery of the future will look like.
For powering electric vehicles, today's technology of choice is lithium-ion. It is also primarily used in mobile phones and notebooks. Nevertheless, lithium deposits are finite. The abundance of lithium in the earth's crust has been calculated at 0.006% (2). The main reserves are stored in hard rock in Australia or in brine in South America.
The member countries of the European Union have comparatively few natural resources. As a result, critical raw materials such as cobalt, manganese, lithium and nickel have to be imported for European battery production.
Alternatives for lithium-ion batteries are being sought both in Europe and worldwide. In this context, sodium-ion technology is currently considered a promising technology.
Sodium - advantages at a glance
The first advantage is that sodium is distributed worldwide on the earth's crust. With a share of 2.36%, it is the sixth most abundant element on earth (3). The deposits are evenly distributed worldwide, so there is no dependence on individual countries. Sodium occurs, for example, in sea salt as sodium chloride.
However, sodium ions are about three times heavier than lithium ions and thus have a lower energy density. Therefore, sodium technology has been identified as a relevant technology for the future.
Why sodium is also of interest for battery technology
Scientists assume that sodium-ion batteries will be cheaper than lithium-ion batteries. They are also expected to be safer. It is estimated that the safety of sodium-ion technology will approach that of lead-acid technology. Compared to lead-acid batteries, they are expected to have better cycle life and faster charging. In addition, they are expected to perform better at low temperatures.
Sodium-ion technology is a so-called drop-in technology. Drop-in technology because the electrochemical processes of a sodium-ion and lithium-ion battery are identical and thus the same production facilities can be used.
Sodium-ion batteries are free of lithium, copper and cobalt. This makes their production independent of critical raw materials. Instead of graphite, non-graphitised hard carbon is used for the anodes, which requires less energy to produce. No natural raw material is mined, because hard carbon can be obtained from biowaste, among other things.
The first vehicles with sodium-ion batteries were already tested in China in 2022. As part of the "Battery 2020 Transfer" funding, BAM, the Federal Institute for Materials Research and Testing, is researching new types of materials for the anodes of sodium-ion batteries (4).
We at HOPPECKE are also looking into future technologies and the possible use of sodium-ion batteries in industrial applications. The first prototype cells are currently being tested in our laboratories. In addition, HOPPECKE is currently applying for third-party funding in an industrial and scientific consortium to further develop this technology.
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