Enhancing All-Solid-State Battery Stability with Light Treatment

A technology that enhances the stability of "high-nickel cathodes" using only light treatment has been developed. High-nickel cathodes are a key material in all-solid-state batteries. The newly developed technology is attracting attention as a breakthrough that can simultaneously improve both the lifespan and stability of next-generation batteries to be used in electric vehicles and energy storage systems (ESS).

Ultrafast heat treatment process using light. National Research Foundation of Korea

According to the National Research Foundation of Korea, a research team led by Professor Youngbum Kim at Hanyang University announced on April 1 that they have developed a technology to address the performance degradation of high-nickel cathode materials for all-solid-state batteries using an ultrafast heat treatment process with intense light.

All-solid-state batteries, which use solid electrolytes instead of liquid ones, are regarded as next-generation battery technology because they lower fire risks and increase energy density.

However, "nickel-rich" cathode materials, which have a high nickel content, offer high energy storage capacity but suffer from rapid performance deterioration, as their structure collapses or reacts with the solid electrolyte during charging and discharging. Cathode materials are the most important component in lithium-ion batteries, as they determine both capacity and voltage.

To address the drawbacks of nickel-rich cathode materials, coating and doping technologies have been introduced. However, these require additional processes and heat treatment, which increase time and costs, and they also face limitations in mass production.

The research team solved this issue using a flash-light sintering (FLS) process, which irradiates strong light for several milliseconds (ms).

Flash-light sintering is a next-generation sintering process that uses the intense white light energy from a xenon lamp to densify materials in a very short time (ms). This process instantly heats only the surface of the material using the strong light emitted from the xenon lamp. As a result, the cathode surface can be directly processed without the need for additional coating or precursors (intermediate substances before becoming a final material).

Professor Youngbum Kim, National Research Foundation of Korea

When this process was applied, the team confirmed that the surface of the cathode was instantly heated to over 900 degrees Celsius, while the interior remained at around 63 degrees, allowing for selective surface modification without structural damage.

In particular, the self-formed protective layer created on the cathode surface by this process served as a chemical barrier that blocked reactions between the cathode and the sulfide solid electrolyte, and as a support that suppressed cathode structure collapse during charging and discharging.

Performance evaluations showed that cathode materials processed using the FLS method demonstrated significant performance improvement in all-solid-state batteries. While conventional materials retained only 55% of their capacity after 100 charge-discharge cycles, FLS-processed materials maintained a retention rate of approximately 81%. Notably, under high-voltage conditions, FLS-processed materials exhibited nearly twice the stable capacity retention compared to conventional materials.

Professor Kim stated, "This research has enabled us to solve both the interfacial stability between the cathode and electrolyte, and the structural collapse issue—two core challenges of all-solid-state batteries. It is meaningful in that we have presented a new manufacturing platform for efficiently producing high-performance battery materials through an ultrafast light process."

This research was supported by the Global Research Laboratory project of the Ministry of Science and ICT and the National Research Foundation of Korea. The results were recently published online in the international journal Advanced Functional Materials, a leading journal in materials engineering.

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