Pukyong National University

Pukyong National University Develops High-Capacity Anode Material for Next-Generation Sodium-Ion Batteries

-Professor Kyung-Ho Kim’s Research Team Achieves High-Rate, High-Capacity Performance Using Abundant Raw Materials

-Findings Published in the International Journal ‘Advanced Science’

Professor Kyung-Ho Kim’s research team in the Major of Materials Science and Engineering at Pukyong National University has developed a new anode material that can overcome the limitations of hard carbon anodes used in commercial sodium-ion batteries, particularly their relatively low capacity and limited high-rate performance.

The team developed a new magnesium phosphide (MgP₄) anode material based on magnesium (Mg) and red phosphorus (P), both of which are abundant resources with relatively stable supply chains. They then applied a stepwise carbon-compositing technique in which a small amount of MgP₄ is incorporated into a hard carbon matrix. The approach was inspired by graphite？silicon composite anode technology, which is widely used in lithium-ion batteries for electric vehicles.

In lithium-ion batteries, a commercialized approach involves incorporating a small amount of high-capacity silicon into lower-capacity graphite to increase energy density. Sodium-ion batteries have attracted attention as an alternative to lithium-ion batteries due to their cost competitiveness and safety. However, because they use sodium ions instead of lithium ions, silicon cannot exhibit the same high-capacity characteristics. This makes it difficult to directly apply the composite anode strategy used in lithium-ion batteries.

To address this challenge, the research team introduced magnesium phosphide (MgP₄), formed by alloying magnesium (Mg) with red phosphorus (P), a potential alternative to silicon, to overcome the flammability and low electrical conductivity of red phosphorus. By incorporating MgP₄ into hard carbon through a stepwise compositing process, the team successfully improved both capacity and high-rate charge？discharge performance while maintaining the excellent stability and processability of hard carbon.

Professor Kyung-Ho Kim said, “This study confirmed the potential of hard carbon-based composite anodes. If the performance of the composite is further improved through additional modification and particle-size control of high-capacity compounds while minimizing the amount added to hard carbon, we expect it could develop into a next-generation hard carbon composite anode platform following the single hard carbon anodes currently at the commercialization stage.”

The research team included Professor Kyung-Ho Kim of Pukyong National University as the corresponding author, post-master’s researcher Si-On Ha as the first author, master’s student Dong-Won Kim, doctoral student Do-Yeon Lee of Seoul National University, Dr. Won-Sik Kim, Professor Sung-Hyun Hong, and Dr. Min-Gyu Lee of Northwestern University in the United States.

The study was supported by the Individual Basic Research Program and the Innovation Research Center (IRC) Program funded by the Ministry of Science and ICT and the National Research Foundation of Korea. The paper presenting the findings, titled “MgP4/CNT-Graphene Embedded in Hard Carbon Matrix as a High-Capacity Anode for Next-Generation Sodium-Ion Batteries,” was published in the July issue of ‘Advanced Science’ (IF 14.1), a leading international journal in materials engineering and interdisciplinary science. <Pukyong Today>