South Korean Researchers Look to Develop a New Electrode Structure for Solid-State Batteries

April 12, 2021 by Alessandro Mascellino

South Korean researchers have developed a new type of electrode structure for all-solid-state secondary batteries.

The discovery could significantly contribute to the increase in energy density of solid-state batteries. The research findings were published in the CS Energy Letters scientific journal last December.


South Korean Researchers Look to Develop a New Electrode Structure for Solid-State Batteries
Researchers working on the new type of electrode structure for all-solid-state secondary batteries. Image used courtesy of ETRI


A Technical Partnership

The new electrode structure was designed and created as part of a joint research project between the Electronics and Telecommunications Research Institute (ETRI) and Daegu Gyeongbuk Institute of Science and Technology (DGIST).

Founded in 1976, ETRI is a non-profit government-funded research institute based in Daejeon, South Korea.

The organization has, throughout the years, contributed to the development of various technologies worldwide, including TDX (Time Division Exchange) and 4M DRAM (Dynamic Random Access Memory)

Today, ETRI is one of the leading research institutes in wireless communication development, with more than 2500 patents filed over the last four decades.


DGIST is a public science and engineering university located in Daegu. 

DGIST was first established as a research institute by the Korean government in 2004, but in 2008 the Institute was officially granted the status of university thanks to an amendment of the Daegu Gyeongbuk Institute of Science and Technology Act.


What are Solid State Batteries?

The term solid-state batteries refers to battery technology utilizing solid electrodes and a solid electrolyte as opposed to liquid or polymer gel electrolytes that are commonly found in lithium-ion or lithium polymer batteries.

Research institutes and manufacturers alike have been experimenting with various materials to be utilized in solid-state batteries, including ceramics and solid polymers.

Generally speaking, solid-state batteries are potentially safer than their lithium counterparts and feature higher energy densities, but they are also typically more expensive to produce.

Moreover, even within solid-state battery applications, there are primary cells that can be only used once, and secondary batteries that can be recharged and used multiple times

According to ETRI and DGIST researchers, recent advances in electronic devices are now making the importance of secondary battery technology in robots, electric cars, energy storage systems (ESS) increasingly more relevant.

Devices utilizing all-solid-state secondary batteries work through a solid electrolyte that transports ions within battery electrodes.

In other words, the electrode structure of a typical all-solid-state secondary cell is composed of a solid electrolyte responsible for ionic conduction, a conductive additive for electron conduction, and a binder to hold these constituent parts together.

Now, South Korean scientists have discovered that ions are transported even between graphite active material particles.


Changing Battery Electrode Structure

The experiment brought the ETRI and DGIST to conceptualize a new type of electrode structure for all-solid-state secondary cells composed only of the active material and the binder.

In fact, as part of the experiment, the scientists proved that, even without the presence of a solid electrolyte additive within the electrodes, the performance of an all-solid-state secondary cell could be superior.

ETRI first scientists theorized the concept, which was then successfully verified at DGIST through electrochemical testing of a virtual model, and named “diffusion-dependent all-solid-state electrode”. 

If adopted by the international community, the new method would lead to the amount of active material in the electrode being increased by up to 98wt%, thus leading to an energy density 1.5 times greater than the conventional graphite composite electrode.

Moving forward, ETRI said it will continue this research using not only graphite but also various other electrode materials.