Research News

Professor Cho Jung-sang] Sodium-ion Solves the Limitations of Lithium-ion Batteries

The significance of secondary battery-related industries has recently increased owing to the implementation of sustainable development goals (SDGs), rapid changes in the mobility industry, and a soaring demand for the energy storage system (ESS) industry.

In May 2022, Chungbuk National University (CBNU) designated Professor Cho Jung-sang, affiliated to its Department of Engineering Chemistry, as the Researcher of the Month based on his research achievements of developing highly efficient long-life sodium-ion secondary batteries that can replace existing commercial lithium-ion secondary batteries.

“CBNU has implemented the Researcher of the Month system to raise the honor of outstanding researchers and enhance research competitiveness.

We would like to celebrate you for being selected as the Researcher of the Month for May 2022. Please share your thoughts on this achievement.”

I am grateful that CBNU has recognized my efforts that I have naturally made as a dedicated researcher in my research field and selected me as Researcher of the Month.

This research project was led by Lee Jae-seob, a master’s graduate student and the first author, and Rakesh Saroha, a postdoctoral researcher and the second author.

Thanks to their remarkable performance, we were able to produce a significant research paper. I truly appreciate their commitment.
 

“In April, your research paper titled ‘Porous Microspheres Comprising CoSe2 Nanorods Coated with N-Doped Graphitic C and Polydopamine-Derived C as Anodes for Long-Lived Na-Ion Batteries’ was published in the prestigious international academic journal NANO-MICRO LETTERS

(IF:23.66, ranking within the top 3.62% in the field-specific IF).

Would you provide a simple and straightforward explanation of what this research paper is about for general readers?”

Jung-Sang Cho, Porous Microspheres Comprising CoSe2 Nanorods Coated with N-Doped Graphitic C and Polydopamine-Derived C as Anodes for Long-Lived Na-Ion Batteries, Nano-Micro Letters, 2022, 1 page

This study applied new nanostructures as electrode materials to replace lithium with sodium-ion in commercial lithium-ion batteries.

However, as sodium-ion is larger and heavier than lithium-ion, it causes great resistance and volume changes of electrode materials during the battery charging and discharging processes, significantly reducing the life and output performance of batteries.

To solve these problems and maximize battery life and performance, we developed complex and porous microspheres comprising CoSe2 nanorods coated with nitrogen-doped graphitic carbon and a polydopamine-derived C layer as electrode materials and applied them as anode materials in sodium-ion batteries. The analytic results verified stable battery operation at significantly high current density of 2 A g-1 despite 5000 cycles of the battery charging and discharging processes.

The developed structure ensures structural stability by using the graphitic C layer, which effectively channelizes stress caused in it during the battery charging and discharging processes, and faster diffusion of sodium-ions based on meticulously controlled mesopores applied in it. Furthermore, the use of N-doped graphitic C with high electrical conductivity facilitates swift movement of electrons in the structure during the battery charging and discharging processes, leading to high output performance.

Existing commercial lithium-ion batteries generally maintain approximately 80% of their capacities during 500 cycles.

On the contrary, the sodium-ion battery applying the new structure proposed in our study exhibited stable performance without capacity reduction during 5000 cycles of the battery charging and discharging processes.

“It is known that this study developed complex porous microspheres comprising CoSe2 nanorods as electrode materials to solve the problems of sodium-ion secondary batteries that can replace expensive lithium-ion secondary batteries.

The developed structure guarantees structural stability and faster diffusion of sodium-ions based on the graphitic C layer and mesoporos applied.

What are the strengths of sodium-ion secondary batteries compared to existing lithium-ion secondary batteries and how will the outcomes of this study influence our daily lives?”

Currently, lithium-ion batteries are widely used for commercial secondary batteries. These batteries are used not only in electric vehicles but also in most electronic devices, such as laptops and mobile phones.

It is difficult to reduce their cost despite the high demand for them owing to the limited reserves of lithium and its increasing price. To overcome this challenge, we focused on using sodium as a solution to be applied in alternative next-generation batteries.

Sodium is an element found in the first group of the periodic table, like lithium, and is abundant on Earth.

It is cheaper than lithium, and its reserves are also greater. Thus, the replacement of lithium with sodium in batteries can significantly reduce the battery price. It is expected that sodium-ion secondary batteries will be widely used in various markets including electric cars and electronic goods.

 “What are your future research plans and goals?”

I have conducted research on designing and synthesizing new nanostructures by applying various powder synthesis techniques, such as precipitation, hydrothermal synthesis, spray pyrolysis, and electrospinning. The scope of research extends to not only batteries but also water electrolysis*, supercapacitors*, drug delivery systems (DDSs)*, and more.

As my research focuses on the design and synthesis of nanostructures, my goals are to design both electrode materials for batteries and nanostructures optimized for various fields and to develop methods to commercialize the designed structures.

At the beginning of this year, I founded a laboratory called JSTECH LAB to produce commercial dentin hypersensitivity* care products based on my DDS-related research outcomes. I am planning to conduct further research on commercializing ongoing research achievements.

 -Water electrolysis: A technology that electrolyzes water to produce high-purity (99.999%) hydrogen (green hydrogen).

-Drug delivery system: A method, technology, or system that controls a drug release rate or effectively delivers drugs to the target area by minimizing their side-effects and maximizing their positive effects.

-Supercapacitor: A component that exhibits significantly enhanced performance in terms of electric capacity compared to other performance-related aspects of a capacitor (condenser) and that is designed for use in batteries.

-Dentin hypersensitivity: A condition in which the dentin of the tooth is exposed or damaged by parenchymal defects, such as wedge-shaped defects, owing to various reasons leading to heightened sensitivity in the affected area and pain even with minor stimuli that are typically painless.

Reference: Naver Encyclopedia