KIST Uses Salmon DNA to Increase Stability of Lithium Batteries

The Korea Institute of Science and Technology (KIST) announced the development of high-performance cathode material for lithium batteries by stabilizing the surface of over-lithiated layered oxides, using the salmon DNA.

The overlithiated layered oxide is a material that contains a large amount of lithium by replacing the transition metal element with the lithium element in the layered structure of the material. The development of high-capacity cathode material is essential to increasing the capacity of lithium batteries. Over-lithiated layered oxides possess a high reversible capacity of 250 mAh/g, which is 100 mAh/g higher than existing commercial materials.

the lithium battery uses salmon DNA image

Over-lithiated layered oxides have a potentially fatal flaw. During charge or discharge cycles, the layered structure of over-lithiated layered oxides may collapse, causing swelling and rendering the battery unusable. The KIST team used transmission electron microscopy to analyze changes in the crystal structure. The researchers achieved this by dividing specific areas into overly lithiated layered oxides from the surface to the inside.

Transmission electron microscopy uses the diffraction phenomenon of electrons accelerated by a high voltage to provide information on the morphology, crystal structure, and elements of various materials at the atomic scale. The analysis results confirmed that the metal layers of the over-lithiated layered oxide started to collapse at the surface by repeated charge/discharge cycling.

Salmon DNA for lithium batteries. The DNA of salmon has a strong affinity for lithium ions, so the researchers used it to control the chemically overlithiated layered oxide on the surface. The researchers found that the DNA of salmon tends to accumulate in aqueous solutions. To solve this problem, the research team synthesized a composite coating material that combines carbon nanotubes (CNT) and salmon DNA. The DNA/CNT mixture is evenly arranged and attached to the surface of the over-lithiated layered oxide, leading to the development of new cathode materials.

conceptual illustration of battery material based on salmon DNA image

The research team conducted comprehensive advanced analysis techniques and found that the electrochemical characteristics of the over-lithiated layered oxide and the mechanism of its structural stability have been improved. The researchers confirmed that the structural degradation can be suppressed during the charge/discharge cycle and the thermal stability is improved.

Professor Sang-Young Lee of the Ulsan National Institute of Science and Technology (UNIST) said: "Unlike pre-existing attempts, this study uses DNA, the basic unit of life, suggesting a new direction for the development of high-performance battery materials."

Kyung Yoon Chung, director of the KIST Energy Storage Research Center, said: "This research of using salmon DNA to increase the stability of lithium batteries is very meaningful because it proposes the use of integrated advanced analytical techniques to stabilize the design factors of high-capacity cathode materials. Based on this research, we will invest more efforts to develop a new material that can replace existing commercial materials."