Technology Developed for Long-Lasting Use from a Single Charge of Electric Vehicle Battery

Ulsan National Institute of Science and Technology Develops Low-Cost Long-Life EV Battery Protection Technology

Professor Jo Jaepil's Special Research Team Introduces Novel 'Cobalt-Boride' Electrode Coating

Affordable Room-Temperature Coatin

Schematic diagram of the developed coating method coating inside the particles and actual microscope images.

[Asia Economy Yeongnam Reporting Headquarters Reporter Kim Yong-woo] A groundbreaking technology to protect large-capacity electrodes has been developed, enabling the commercialization of electric vehicle batteries that can run longer on a single charge.

A domestic research team developed a coating technology that protects large-capacity electrodes (cathode materials). Battery cells using the new coating material maintained stable material structures even after hundreds of charge-discharge cycles and showed about 20% longer lifespan compared to commercial cathode materials.

The research results were published on March 2 local time in Nature Energy, a prestigious journal in the energy field.

The research team led by Distinguished Professor Cho Jae-pil from the Department of Energy Chemical Engineering at Ulsan National Institute of Science and Technology (UNIST, President Lee Yong-hoon) developed a coating technology that can dramatically improve microcracks and chemical instability of cathode particles that degrade battery life.

This innovative technology is notable for its ability to coat not only the particle surface but also the interior of particles at room temperature.

High-nickel materials, considered as large-capacity battery cathode materials, enable high capacity expression and are relatively inexpensive.

However, repeated charging and discharging cause microcracks inside the material particles and side reactions with the battery electrolyte, leading to a rapid decrease in lifespan.

Currently, to protect electrodes, all material surfaces in production are coated with a coating agent and heat-treated at high temperatures above 700°C, but this method causes performance degradation and increased processing costs.

The UNIST research team developed a room-temperature coating technology that allows the protective compound ‘Cobalt Boride (CoxB)’ to penetrate evenly not only on the surface but also inside the cathode particles.

The ‘Cobalt Boride (CoxB)’ material can be coated at room temperature due to its strong bonding with oxygen, a component of high-nickel cathodes.

Cracks usually start on the particle surface and penetrate inward, causing internal cracks, but the newly developed coating method protects both inside and outside of the particles, resulting in excellent lifespan maintenance.

The researchers manufactured batteries using high-nickel cathode materials coated with the agent and commercial artificial graphite as the anode and evaluated the coating performance.

Experimental results showed that even after 500 charge-discharge cycles, the battery retained 95% of its original capacity, which is about 20% better lifespan retention than general high-nickel materials.

UNIST Researcher Yoon Moon-soo (left) and Professor Cho Jae-pil.

First author Moon-su Yoon, a doctoral student in the Department of Energy Engineering at UNIST, explained, “High-nickel materials have a problem of microstructure collapse at temperatures above 45°C, but the newly developed coating method also solved this issue.”

The research team also clarified the principles and phenomena by which the developed coating material improves the structural stability of high-nickel cathode materials through theoretical calculations and atomic-level transmission electron microscopy.

Advisor Distinguished Professor Cho Jae-pil said, “Currently, commercial high-nickel cathode materials commonly use wet coating processes, but there is a high potential risk of infringing already registered U.S. patents, and high-temperature synthesis leads to increased production costs.”

Professor Cho added, “If a large-scale cathode material synthesis process is developed applying the newly developed coating method, it is expected to reduce costs by at least 20% compared to existing coating processes.”

This research was conducted jointly with Professor Ju Li’s research team at MIT (Massachusetts Institute of Technology). (Paper title: Reactive boride infusion stabilizes Ni-rich cathodes for lithium-ion batteries)

Effect of using cathode materials with the developed coating method on battery life retention.

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