| 초록 |
A promising strategy to avoid the formation of microcracks in Ni-rich layered cathodes and associated rapid capacity fading involves the development of cathode materials with single-crystal structures. Unlike conventional Ni-rich layered cathode particles that consist of numerous nano-sized grains, single-crystal cathode particles are not vulnerable to microcracking, because each cathode particle does not contain intergranular boundaries. However, generally, a decrease in particle size is accompanied by an increase in particle strength but the concomitant high surface-to-volume ratio increases the risk of surface degradation. For practical uses, detailed understanding of single-crystal cathodes is essential for the development of this technology. In this study, we comprehensively evaluate the fundamental properties of single-crystal and polycrystalline cathodes with a wide range of Ni-rich compositions. The electrochemical performances of single-crystal and polycrystalline cathodes were correlated with their structural changes to elucidate the dominant capacity fading mechanism of single-crystal cathodes and inform the rational design of advanced cathode materials for LIBs. |
