Scientists have developed a special electrode that allows you to quickly and efficiently extract lithium ions from seawater.
Lithium is the preferred element in modern batteries because it can store more energy per unit weight than other materials. Due to the development of electronic devices and energy storage systems, its annual consumption is increasing and, according to forecasts, by 2025 will reach 500 thousand tons..
Researchers estimate that seawater contains 57 000 times more lithium than on land. The problem lies in its low concentration (about 1 particle in 5 million), which, combined with the high content of sodium ions in the water, significantly complicates the extraction.
Researchers at Stanford University solved the problem by developing a special coated electrode from a thin layer of titanium dioxide. The TiO2 shell acts as a barrier to the passage of large sodium particles, but smaller lithium atoms can pass without problems.
An efficient method for extracting lithium from seawater has been developed
Despite the effectiveness of this coating, sodium accumulates over time on the surface of the protective layer, blocking the filter. The team decided given problem by repeatedly changing the voltage to the opposite. This pushes the ions away from the electrode, but the sodium particle is the first to leave the surface, and the lithium is the last to leave. After ten such cycles, the ratio of recovered lithium to sodium is 1: 1. The whole process takes a few minutes.
Although this method is effective, it is more expensive to recover lithium than traditional onshore mining. Therefore, scientists continue to improve the system and test other types of electrodes..
Recall that recently Russian scientists have created a new material for the production of hydrogen from dirty and salt water.
text: Ilya Bauer, photo: wallhere