Thermal Treatment As a Key Factor for Obtaining Top-Grade Core-Shell NMC Cathode Materials

Abstract

Listen

Translate article

Lithium-ion batteries (LIBs) continue to be one of the main technologies in the energy storage industry, powering various devices from portable electronics to electric vehicles. However, to meet the growing demand for higher energy density, longer cycle life, and improved safety, there is a pressing need for innovative electrode materials[1]. In this presentation, we approach the development of an advanced positive electrode material for LIBs based on a core-shell structure, utilizing lithium nickel manganese cobalt oxide (NMC) with a nickel-rich core and a low-nickel shell.The core-shell structures present a promising route for simultaneously enhancing the performance and stability of LIBs[2]. By incorporating a nickel-rich core, it is possible to leverage its high capacity, while the low-nickel shell ensures reducing undesirable side reactions, such as electrolyte decomposition and transition metal dissolution[3], thereby enhancing safety and longevity of the battery.Our research focuses on electrochemical evaluation of various NMC compositions to determine the best materials for the core and the shell, focusing on specific capacity, rate performance and cyclability. As different stoichiometries of NMC usually require distinctive thermal treatment conditions[4,5], a careful examination is needed in order to ensure proper crystal structure of both the core and the shell. In that regard we conducted a set of in situ and ex situ XRD studies on pristine materials. In combination with electrochemical assessment these results enabled us to match high-capacity nickel-rich NMC for the core with enhanced-stability low-nickel variants for the shell in terms of the best possible compatibility of thermal treatment conditions in mind.This allows us to further study the core-shell NMC materials characterized by both satisfactory electrochemical performance and enhanced cyclic stability. This approach opens the possibility to develop LIBs with higher energy density, prolonged cycle life, and enhanced stability, crucial for meeting the evolving demands in the advancing energy storage sector. This work was funded by the National Science Center in Poland through the Sonata 17 programme (No. UMO-2021/43/D/ST5/03094). [1] M. Li, J. Lu, Z. Chen, K. Amine, Adv. Mater. 2018, 30, 1800561.[2] H. Peiyu, Z. Hongzhou,Z. Zhongyue, Z. Lianqi,X. Xijin, J. Mater. Chem. A, 2017, 5, 4254–4279[3] Li, T., Yuan, XZ., Zhang, L. et al. Electrochem. Energ. Rev. 3, 43–80 (2020).[4] Noh, H. J., Youn, S., Yoon, C. S., Sun, Y. K., J. Power Sources 233, 121– 130 (2013).[5] Zheng, J., Yan, P., Estevez, L., Wang, C, Zhang, J. G., Nano Energy 49, 538– 548 (2018).