GIST Develops High-Capacity Silicon Anode Material for Lithium Secondary Batteries

From the left in the photo: Seoseokho, PhD student; Kim Hyeongjin, professor; Yoon Hocheol, master's student. Photo by GIST.

[Asia Economy Honam Reporting Headquarters Reporter Cho Hyung-joo] Professor Kim Hyung-jin's research team at the Graduate School of Energy Convergence, GIST (Gwangju Institute of Science and Technology), announced on the 25th that they have improved the performance and durability of silicon anodes, which are attracting attention as next-generation lithium secondary battery anodes.

Silicon anodes theoretically have more than 10 times the energy density of conventional graphite commercial anodes, and are gaining attention as next-generation anodes due to their economical and eco-friendly materials.

In particular, they can be used for medium-to-large energy storage devices that require high energy density and power density, such as large-capacity energy storage systems (ESS) and electric vehicles, leading to fierce competition worldwide for their development.

However, the non-conductive nature of silicon and the low lifespan caused by volume expansion of silicon during charge-discharge cycles have been obstacles to commercialization.

The research team succeeded in improving the electrical conductivity of silicon electrodes and alleviating mechanical stress within the electrode generated during charge-discharge by applying a simple electrode heating process to induce silicon-copper alloy reactions and carbonize the electrode binder.

As a result, the silicon-copper-carbon composite anode showed significantly enhanced electrochemical properties. In particular, while the conventional silicon anode failed to properly charge and discharge at a high current density of 4 A/g, the silicon-copper-carbon composite anode maintained a high capacity of 1,776 mAh/g.

Professor Kim Hyung-jin said, “This research is especially centered on the fusion of various applications between silicon and heterogeneous metals and electrode processing technology. It is hoped that, by overcoming the limited use of silicon materials through composite research with heterogeneous metals, it will contribute to the performance improvement of lithium secondary batteries in the future.”

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