Researchers at the Daegu Gyeongbuk Institute of Science & Technology (DGIST) said they have developed a new electrolyte technology through magnetic nanoparticles that can improve both the stability and lifespan of next-generation lithium batteries.

Lithium metal is actively being seen as the next-generation anode material.

Its commercialization was hindered until now owing to the problem of the generation of the dendrite, which is heavily dependent on the ion transport phenomenon in the electrolyte.

If a lithium metal battery is manufactured with the electrolyte developed by the team and used while applying a rotating magnetic field on the outside, it can dramatically improve lifespan compared to the existing system, the researchers affirmed.

At present most commercialized batteries use graphite electrodes as negative electrodes. However, a graphite negative electrode comes with its own setbacks; in terms of energy density owing to its size and weight occupying a lot of space inside the battery.

This limits long battery operation and therefore the demand for a lighter and smaller anode material has come to light.

The development is expected to solve the problem of “dendrite growth” – a twig-shaped crystal that accumulates on the surface of the anode during the lithium battery charging process — by turning the liquid electrolyte into a dynamic state and can possibly accelerate the commercialization of next-generation batteries.

Professor Lee Hong-Kyung of the Department of Energy Science and Engineering at DGIST explained that it is a new concept electrolyte system that can create a dynamic electrolyte and can change the paradigm of electrolyte research through magnetic nanoparticles.

The team of researchers produced a nano-spin bar (NSB) that responds to an external magnetic field so that the static electrolyte solution in the battery can be turned to a dynamic state and added to the electrolyte solution to generate micro-convection.

The team found out it was possible to rotate NSBs distributed throughout the electrolyte by applying an external rotating magnetic field to transmit power remotely.

This resulted in facilitating fast ion transport while reducing ion diffusion by about 35% compared to the previous method, thus enabling homogeneous ion transportation. The team said when the ion transport velocity is faster and the homogeneity is improved, it is easier to control dendrite.

The team said the dynamic ion transport realized through the application of magnetic nanoparticles (NSB) and an external magnetic field can promote rapid and uniform transport of lithium ions.

Additionally, the same effect could be achieved when they were added to other electrolytes.

The research was carried out with support from the Ministry of Trade, and the POSCO TJ Park Foundation, along with the National Research Foundation of Korea’s Excellent New Research.

In December last year, researchers at the University of Sydney claimed to have developed a new, low-cost sodium-sulfur battery with four times the energy capacity of lithium-ion batteries.

In the same month, researchers at the Chinese Academy of Sciences (CAS) claimed to have built a stable kilowatt-scale aqueous redox flow battery (AOFB) with high-performance organic redox-active molecules for renewable storage.