Synthesis of Lithium-Nickel-Cobalt-Manganese-Aluminum Oxide-Based Ni-Rich Lib Cathode through Slug-Flow Manufacturing Platform

Abstract

Lithium ion batteries (LIBs) with high specific capacity and long cycle life is critically required for high energy applications, such as electric vehicle technology. Owing to the high capacity, various Ni-rich cathodes (with Ni-content ≥ 80 %), including lithium-nickel-cobalt-manganese (NCM), lithium-nickel-cobalt-aluminum (NCA)-based layer oxides are widely explored to fabricate high performance LIBs.1 However, increase in Ni-content in the layered oxides aggravated the issues like, poor rate capability and short cycling performance due to the extensive volume contraction/expansion and the phase change above 4.2 V vs. Li/Li+. One rational strategy to achieve both high capacity and high mechanical stability for the Ni-rich cathodes is optimized doping of Al in the NCM moiety. Presence of Mn and Al in the same structure ensures high mechanical as well as thermal stability of the lithium-nickel-cobalt-manganese-aluminum oxide (NCMA).2 The performance of NCMA largely depends on the atomic percentage of each transition metals in the crystal structure. Hence proper control over the elemental composition and morphology is critically required. Among the various synthesis methods, stirred tank reactor-based co-precipitation synthesis through batch or semi-batch process is commonly used to synthesize phase pure NCMA precursors. However, the stirred tank reactor-dependent synthesis of battery precursors suffers from intrinsic batch-to-batch composition variability, increased agglomeration/breakage of particles and scaling up issues. The main goal of our research is to develop a low-cost scalable manufacturing platform for Ni-rich cathodes.3 Herein, we have utilized three-phase slug-flow reactor to produce NCMA oxalate precursor particles with high phase purity, homogeneity in composition and uniformity in particle size distribution (Figure 1). Here, the growth of precursor particles follows the co-precipitation chemistry and each of the self-circulating slugs works as the milliliter scale reactors, which offers better mixing of various reagents of the reaction mixture.3 The reactor is advantageous in terms of selective feeding of components, spatially uniform reaction conditions with high production rate and good control over the precursor composition and particle size, which further determines the tap density of the final material.4 In this work, NCMA oxalate with the compositional variation of Co= 6 – 10 % are synthesized through slug-flow, followed by high temperature lithiation of the precursor at high temperature of 750 oC in oxygen flow to obtain the final oxide material. The ammonium oxalate was used as the primary precipitation agent and ammonium hydroxide plays the roles of pH-controller as well as works as the chelating agent. The as-synthesized NCMA shows a high specific capacity of ~196 mAh g-1 at 0.1 C. The battery performance of the NCMAs are further analyzed by rate capability and cycling performance profiles. References Muralidharan, E. C. Self, M. Dixit, Z. Du, R. Essehli, R. Amin, J. Nanda, I. Belharouak, Adv. Energy Mater. 2022, 12, 2103050. H. Kim, L. Y. Kuo, P. Kaghazchi, C. S. Yoon, Y. K. Sun, ACS Energy Lett. 2019, 4, 576−582. B. Gupta, M. Jiang, M. Mou, A. Patel, J. H. Mugumya, S. Mallick, H. Lopez, M. p. Paranthaman, 2022 Meet. Abstr., MA2022-02, 25. DOI 10.1149/MA2022-02125. Jiang, Z. Zhu, E. Jimenez, C. D. Papageorgiou, J. Waetzig, A. Hardy, M. Langston, R. D. Braatz, Crys. Growth Des. 2014, 14, 851-860. Mou, A. Patel, S. Mallick, J. Mugumya, M. L. Rasche, M. P. Paranthaman, H. Lopez, G. P. Pandey, R. B. Gupta and M. Jiang, ACS Omega 2022, 7, 46, 42408–42417. Figure 1