Is the Era of Generating Electricity from Car Exhaust Coming? New Technology Improves Power Generation Efficiency Using Heat Temperature Difference

UNIST Professor Son Jaesung's Team Develops 3D Printing Technology for Honeycomb Thermoelectric Materials that Distribute Force

Improved Durability and Efficiency... Lightweight Design Expected to Recycle Waste Heat in Aircraft and Vehicles

From the left, Professor Son Jaesung, Researcher Joo Hyejin, Researcher Choo Seungjun, Professor Chae Hanggi.

[Asia Economy Yeongnam Reporting Headquarters, Reporter Kim Yong-woo] Converting heat generated from car exhaust into electricity and reusing it? A breakthrough technology that significantly improves the durability and efficiency of thermoelectric generators has emerged.

Thermoelectric generation is a next-generation power generation method that converts temperature differences into electricity. It can convert the heat from waste gases emitted by factories, aircraft, and automobiles into electricity, making it a promising energy recycling technology.

The newly introduced technology utilizes the honeycomb structure's characteristic of effectively distributing force to prevent damage to thermoelectric materials. It also effectively suppresses heat diffusion, further improving generator efficiency.

Ulsan National Institute of Science and Technology (UNIST, President Lee Yong-hoon) announced on the 15th that a team led by Professors Son Jae-sung and Chae Han-gi from the Department of Materials Science and Engineering, along with Professor Kwon Beom-jin from Arizona State University, developed a technology that 3D prints the thermoelectric material copper selenide (Cu2Se) into a honeycomb shape to enhance the durability and efficiency of generators.

According to the research team, thanks to the newly developed ink made from thermoelectric materials, they were able to 3D print complex honeycomb structures.

The principle used is the Seebeck effect, where a temperature difference at both ends of the thermoelectric material generates an electric current within the material.

The thermoelectric material, which is the core of this generator, has weaker mechanical durability against impacts compared to other material groups.

Additionally, during operation, it is repeatedly exposed to thermal expansion and contraction as well as mechanical vibrations, making it prone to structural damage such as microcracks. Therefore, new technology to enhance durability was necessary.

Figure of 3D printing process study of copper selenide (Cu2Se).

The joint research team introduced a new technique to fabricate thermoelectric materials with cellular architectures.

Cellular architectures refer to structures where multiple unit cells are connected without gaps. By making the unit cells hexagonal prisms like a honeycomb, external forces are effectively dispersed, and less raw thermoelectric material is used, enabling weight reduction.

Seungjun Chu, first author and integrated MS-PhD student at UNIST’s Department of Materials Science and Engineering, said, “In this experiment, we fabricated copper selenide material into a cellular architecture, significantly increasing mechanical strength.”

Chu explained, “This material originally exhibits excellent thermoelectric performance at high temperatures (around 800℃), but its durability was easily weakened due to thermal expansion.”

The research team used an inorganic binder (selenium) to create ink suitable for 3D printing.

To produce thermoelectric materials in a high-viscosity ink form, a binder is necessary, but commonly used organic binders are not completely removed during heat treatment processes.

Comparison Study of Thermoelectric Generator Performance by Thermoelectric Material Form Figure.

Residual organic binders reduce electrical conductivity, lowering the efficiency of thermoelectric materials.

Professor Chae Han-gi explained, “This technology prevents degradation of material properties such as electrical conductivity, making it a fundamental technology that can be applied to 3D printing various semiconductor materials.”

The performance of generators made with honeycomb-structured thermoelectric materials was also simulated using computers.

Experimental results showed that the honeycomb structure had over 26% higher performance in converting temperature differences into electricity compared to rectangular flat plate generators.

This is because the honeycomb structure effectively suppresses heat diffusion from the electrodes attached to the thermoelectric material. When heat diffuses to the surrounding area and the temperature difference decreases, thermoelectric generation efficiency drops.

Professor Son Jae-sung said, “This is an excellent technology that minimizes raw material loss,” and added, “It is expected to be applied in aerospace and automotive industries where both weight reduction and durability are required.”

This research was published online on June 10 in the world-renowned scientific journal Nature Communications. The research was supported by Samsung Electronics through the Samsung Future Technology Development Program.

This content was produced with the assistance of AI translation services.