Discharge Characteristics of High-Loading Coated Cathode Active Materials for High-Capacity High-Efficiency Secondary Batteries Implementation
Authors: Jeon DoMan 
Published: December 2024

In response to the demand for secondary batteries, mass production of secondary battery materials is required, leading to the need for significantly increased production capacity and the development of high-speed production systems for electrode materials. Furthermore, in accordance with global environmental regulations and energy management regulations, reducing carbon emissions is necessary for enhancing future competitiveness through the application of eco-friendly and digital processes. Additionally, to meet the demands of commercializing high-energy-density secondary batteries and achieving carbon neutrality, it is necessary to establish advanced and efficient electrode manufacturing systems. Therefore, the design and development of processes for dispersing components that determine the physical properties of slurries, as well as mixing and coating processes for battery manufacturing, are crucial. Density control ensures accurate material composition, and control of component ratios and viscosity is essential for ensuring consistency in slurry manufacturing processes. During discharge, as the active material at the cathode undergoes reduction, the energy difference with the reference electrode gradually decreases, resulting in a decrease in cell potential. The slope change of the discharge curve is influenced by factors such as the extent of lithium ion diffusion at the surface of the active material particles, phase transitions of the active material, collapse of crystal structure, and leaching of transition metal ions comprising the active material into the electrolyte. Moreover, even at the same current density, charge and discharge curves may vary depending on factors such as particle size and size distribution of the active material, temperature, mixing conditions of active material/binder/conductive agent, electrolyte characteristics, and porous structure of the separator. In this study, the evaluation of electrode characteristics of active materials was conducted to optimize coating conditions and mixing conditions for achieving high efficiency and high loading for the implementation of high-energy-density secondary batteries. Through evaluation based on C-rate according to Loading Level, analysis of capacity implementation characteristics based on electrode density was performed, aiming to apply it to the development of carbon reduction-type high-loading, wide-electrode slurry coating equipment systems for the implementation of high-energy-density secondary batteries. Expectations include the development of carbon reduction process technologies through maximum homogeneity, enhancing production speed, and energy savings in processes.

Secondary battery, Cathode active material, Slurry, Loading level, C-rate

This work was supported by the Technology Innovation Program (RS-2022-00155881, Development of high-efficiency and high-loading coating system for implementation of 350Wh/kg secondary battery) funded By the Ministry of Trade, Industry & Energy(MOTIE, Korea)