Ni-Rich Li[Ni1−x−YCoxBy]O2 Cathode Materials for Next Lithium Batteries

Abstract

To achieve a longer driving range of electric vehicles (EVs) per charge, it is necessary that the development of advanced cathode materials, which largely determine the capacity of lithium-ion batteries. Currently, classical cathodes deployed in current EVs, layered Li[NixCoy(Al orMn)1−x−y]O2 (Al = NCA or Mn = NCM) oxide materials, has achieved the best performances for commercialization. However, these cathodes should be further improved to be competitive in the global market.1 Ni-rich NCA and NCM cathodes, delivering ever-closer to their theoretical specific capacity, are considered as promising candidates. However, increasing Ni content compromises battery lifetime and thermal stability due to rapid capacity fading and an abundance of unstable Ni4+ species, as observed in LiNiO2.2,3 Therefore, the development of new cathode materials that can overcome rapid capacity fading is necessary.In this presentation, we suggest a novel cathode material by introducing boron to the binary system Li[Ni0.9Co0.1]O2 (NC90) to create a new class of layered cathode materials, Li[Ni1−x−yCoxBy]O2 (NCB), to supplement NCM and NCA.4 The microstructure of NCB cathodes was tailored by adjusting the boron fraction, as the shape and dimensions of the primary particles depend on the boron fraction. The dramatic difference between the particle microstructure of an NCB cathode and those of NCA and NCM cathodes was confirmed. The NCB cathode exhibited a higher capacity with outstanding capacity retention, compared to the conventional NCA and NCM cathodes. A series of NCB cathodes with 0.5, 1.0, 1.5, and 2 mol% B systematically characterized to investigate the capacity fading mechanism and to determine the optimal microstructure for better cycling stability.References D. Andre, S.-J. Kim, P. Lamp, S. F. Lux, F. Maglia, O. Paschos, B. Stiaszny, J. Mater. Chem. A 2015, 3, 6709.H.-H. Ryu, K.-J. Park, C. S. Yoon, Y.-K. Sun, Chem. Mater. 2018, 30, 1155.D.-W. Jun, C. S. Yoon, U.-H. Kim, Y.-K. Sun, Chem. Mater. 2017, 29, 5048.H.-H. Ryu, N.-Y. Park, D. R. Yoon, U.-H. Kim, C. S. Yoon, Y.-K. Sun, Adv. Energy Mater. 2020, 10, 2000495.