The Future of Batteries: Sodium-ion Technology

Researchers at the Karlsruhe Institute of Technology (KIT) are using computer simulations to study new battery materials. They’re focusing on sodium-ion batteries, which are similar to lithium-ion batteries but use more readily available materials.

One of the materials they’re studying is sodium-nickel-manganese oxide. When used in a battery, this material changes its structure during charging, which can cause the battery to lose capacity over time.

The sodium-nickel-manganese oxide used as the cathode material in these batteries undergoes modifications in its crystal structure during charging. This leads to an elastic deformation and the crystal contracts, which may cause cracking and a reduction in capacity. The simulations show that this mechanical influence significantly determines the charging time of the material.

Furthermore, the researchers combined microstructured models with slow charge and discharge experiments to study the NaXNi1/3Mn2/3O2 layered oxide. They found that the material exhibits several degradation mechanisms causing a loss of capacity, making it not yet suitable for commercial applications.

“Computer models can depict various length scales, from the arrangement of atoms in electrode materials to their microstructure to the cell as the functional unit of any battery,” Daubner says. To study the NaXNi1/3Mn2/3O2 layered oxide, microstructured models were paired with slow charge and discharge experiments. The material was found to display several degradation mechanisms leading to a loss of capacity. Hence, it is not yet fit for commercial applications. A change in the crystal structure results in an elastic deformation. The crystal contracts, which may lead to cracking and a reduction in capacity. Simulations by INT and IAM-MMS show that this mechanical influence significantly determines the charging time of the material. These results were confirmed by experimental studies at ZSW.

The study’s findings can be partially applied to other layered oxides. “We now understand the fundamental processes and can focus on developing battery materials that are durable and can be charged as swiftly as possible,” Daubner concludes. This could pave the way for the widespread adoption of sodium-ion batteries in the next five to ten years.

In conclusion, the research being conducted at KIT is paving the way for the future of battery technology. The exploration of sodium-ion batteries and their potential to replace lithium-ion batteries is a promising development. While challenges remain, particularly in the area of rapid charging and the resulting structural changes in the cathode material, the researchers are making significant strides. The hope is that, with continued study and innovation, sodium-ion batteries could become a common and efficient energy storage solution in the next decade. This would mark a significant step forward in our quest for sustainable and accessible energy solutions.

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Source: CleanTechnica / DOI: 10.1038/s41524-024-01258x