The possibility of using "self-ordering" materials to manufacture batteries of higher storage capacity and reduced degradation through use has taken a step nearer to becoming a reality, thanks to the study conducted by the Japanese researcher Atsuo Yamada from the University of Tokyo. The findings of the study published in the current issue of the journal Nature Communications, and in which CIC energiGUNE has taken active part through its researchers Marine Reynaud and Montse Casas-Cabanas, lay the ground for a new way of designing materials for batteries,
CIC energiGUNE´s involvement in this project, in which the Institute for Solid State Chemistry Bordeaux has also collaborated, has been focused on developing a specific X-ray diffraction analysis programme. On an international level, the Basque Research Centre is one of the few organisations capable of providing this type of service, making its contribution crucial to the project.
As Montse Casas-Cabanas, researcher at CIC energiGUNE and the person responsible for this part of the project, explains: “Our collaboration in this project is the result of our knowledge and experience in the structural and microstructural characterization of battery materials, and in particular of the FAULTS program developed by us in partnership with Dr. Juan Rodriguez-Carvajal of the Institut Laue Langevin in Grenoble, France”.
According to Dr. Casas-Cabanas, the study material of this publication is characterised by its layered structure, i.e. atoms are organised in different layers stacked on top of each other, like Lego bricks. However, instead of being perfectly stacked, the layers of atoms are slightly displaced on top of each other, forming what are known as "planar defects" and resulting in a disordered structure. Analysis of this type of disordered structure requires a specific methodology, different from the one generally used in the vast majority of material studies.
The specific contribution of CIC energiGUNE in this project has been to study the reaction mechanism of the material selected. As Montse Casas-Cabanas adds: “Our FAULTS software and analysis have enabled us to observe and understand this mechanism for the first time. This is a new mechanism that involves self-ordering of the structure during the process of charging the battery, and which is also reversible, as battery discharge triggers a return to the original disordered structure”. For Dr. Casas-Cabanas, the process of ordering-disordering can be defined as “atomic choreography”.
Thus, the process increases the capacity of the material - which increases energy storage capacity - and aids reversibility of the reaction, which reduces unit degradation. The CIC energiGUNE researcher concludes: "This ability to self-organize represents a new strategy for the design of new electrode materials that will enable the energy storage capacity of lithium and sodium batteries to be increased".