Thermodynamic analysis of Li-Ni-Co-Mn-H₂O system and synthesis of LiNi_0.5Co_0.2Mn_0.3O₂ composite oxide via aqueous process

Abstract

The constructed potential-pH diagrams of Li-Ni (Co, Mn)-H₂O system indicate that the LiNiO₂, LiCoO₂ and LiMnO₂ are thermodynamically stable in aqueous solution within the temperature range of 25-200 °C and the activity range of 0.01-1.00. A predominant co-region of LiNiO₂, LiCoO₂ and LiMnO₂ oxides (Li-Ni-Co-Mncomposite oxide) is found in the Li-Ni-Co-Mn-H₂O potential-pH diagrams, in which the co-precipitation region expands towards lower pH with rising temperature, indicating the enhanced possibility of synthesizing Li-Ni-Co-Mn composite oxide in aqueous solution. The experimental results prove that it is feasible to prepare the LiNi_0.5Co_0.2Mn_0.3O₂ cathode materials (NCM523) by an aqueous routine. The as-prepared lithiated precursor and NCM523 both inherit the spherical morphology of the hydroxide precursor and the obtained NCM523 has a hexagonal α-NaFeO₂ structure with good crystallinity. It is reasonable to conclude that the aqueous routine for preparing Ncm cathode materials is a promising method with the guidance of the reliable potential-pH diagrams to some extent.

Keywords

aqueous process / potential-pH diagrams / thermodynamics / LiNi_0.5Co_0.2Mn_0.3O₂ / cathode materials

References

[1] PorthaultH, Le, CrasF, Baddour-HadjeanR, Pereira-RamosJ P, FrangerS. One step synthesis of lamellar R-3m LiCoO2 thin films by an electrochemical–hydrothermal method [J]. Electrochimica Acta, 2011, 56(22): 7580-7585

[2] LiL, LiY-j, XuC, PapangelakisV G, ChuG, LiG-l, WangX-y, KongLong. E-pH diagrams from 333.15 to 453.15 K for lithium-titanium composite oxides and their synthesis in aqueous solution [J]. Hydrometallurgy, 2014, 142: 131-136

[3] HouP-y, ZhangH-z, DengX-l, XuX-j, ZhangL-qi. Stabilizing the electrode/electrolyte interface of LiNi_0.8Co_0.15Al_0.05O₂ through tailoring aluminum distribution in microspheres as long-life, high-rate, and safe cathode for lithiumion batteries [J]. ACS Applied Materials & Interfaces, 2017, 9(35): 29643-29653

[4] SongS W, HanK S, YoshimuraM. Effect of 20-200 °C fabrication temperature on microstructure of hydrothermally prepared LiCoO2 films [J]. Journal of the American Ceramic Society, 2004, 83(11): 2839-2844

[5] CowanR L, StaehleR W. The thermodynamics and electrode kinetic behavior of nickel in acid solution in the temperature range 25 to 300 °C [J]. Journal of the Electrochemical Society, 1971, 118(4): 557

[6] HouP-y, LiF, SunY-y, LiH-q, XuX-j, ZhaiT-you. Multishell precursors facilitated synthesis of concentration-gradient nickel-rich cathodes for long-life and high-rate lithium-ion batteries [J]. ACS Applied Materials & Interfaces, 2018, 102924508-24515

[7] LiF, KongL-l, SunY-y, JinY-c, HouP-yu. Micron-sized monocrystalline LiNi_1/3Co_1/3Mn_1/3O₂ as high-volumetric-energy-density cathode for lithium-ion batteries [J]. Journal of Materials Chemistry A, 2018, 6(26): 12344-12352

[8] HouP-y, YinJ-m, DingM, HuangJ-z, XuX-jin. Surface/interfacial structure and chemistry of high-energy nickel-rich layered oxide cathodes: Advances and perspectives [J]. Small, 2017, 13(45): 1701802

[9] HouP-y, ZhangH-z, ZiZ-y, ZhangL-q, XuX-jin. Core–shell and concentration-gradient cathodes prepared via co-precipitation reaction for advanced lithium-ion batteries [J]. Journal of Materials Chemistry A, 2017, 594254-4279

[10] LeeM H, KangY J, MyungS T, SunY K. Synthetic optimization of Li[Ni_1/3Co_1/3Mn_1/3]O₂ via co-precipitation [J]. Electrochimica Acta, 2004, 50(4): 939-948

[11] LuH-q, ZhouH-t, SvenssonA M, FossdalA, SheridanE, LuS-g, Vullum-BruerF. High capacity Li[Ni_0.8Co_0.1Mn_0.1O₂ synthesized by sol–gel and co-precipitation methods as cathode materials for lithiumion batteries [J]. Solid State Ionics, 2013249250

[12] LinY-k, LuC-hsin. Preparation and electrochemical properties of layer-structured LiNi1/3Co1/3Mn1/3-yAlyO2 [J]. Journal of Power Sources, 2009, 189(1): 353-358

[13] WangZ-x, FangH-s, YinZ-l, LiX-h, GuoH-j, PengW-jie. Synthesis and characterization of high-voltage cathode material LiNi_0.5Mn_1.5O₄ by one-step solid-state reaction [J]. Journal of Central South University of Technology, 2005, 12(1): 54-58

[14] LiD-c, MutaT, ZhangL-q, YoshioM, NoguchiH. Effect of synthesis method on the electrochemical performance of LiNi_1/3Mn_1/3Co_1/3O₂ [J]. Journal of Power Sources, 2004, 132(12): 150-155

[15] LinB, WenZ-y, GuZ-h, HuangS-hua. Morphology and electrochemical performance of Li[Ni_1/3Co_1/3Mn_1/3]O₂ cathode material by a slurry spray drying method [J]. Journal of Power Sources, 2008, 175(1): 564-569

[16] ShuiM, GaoS, ShuJ, ZhengW-d, XuD, ChenL-l, FengL, RenY-long. LiNi_1/3Co_1/3Mn_1/3O₂ cathode materials for LIB prepared by spray pyrolysis. II. Li⁺ diffusion kinetics [J]. Ionics, 2013, 19(1): 47-52

[17] PengQ-l, ZhouH-h, HuangZ-h, ChenJ-h, KuangY-fei. Catalytic graphitization of polyacrylonitrile-based carbon fibers coated with Prussian blue [J]. Journal of Central South University of Technology, 2010, 17(4): 683-687

[18] MyungS T, LeeM H, KomabaS, KumagaiN, SunY K. Hydrothermal synthesis of layered Li[Ni_1/3Co_1/3Mn_1/3]O₂ as positive electrode material for lithium secondary battery [J]. Electrochimica Acta, 2005, 50(24): 4800-4806

[19] ZhaoZ-w, HuoG-sheng. Thermodynamic and kinetic research of Li₂O-H₂O system [J]. The Chinese Journal of Nonferrous Metals, 2004, 8: 2149-2152

[20] MakimuraY, OhzukuT. Lithium insertion material of LiNi_1/2Mn_1/2O₂ for advanced lithium-ion batteries [J]. Journal of Power Sources, 2003, 119: 156-160

[21] LiX-l, HeW-x, ChenL, GuoW, ChenJ-j, XiaoZ-hui. Hydrothermal synthesis and electrochemical performance studies of Al₂O₃-coated LiNi_1/3Co_1/3Mn_1/3O₂ for lithiumion batteries [J]. Ionics, 2014, 20(6): 833-840

[22] WenS-m, ZhaoZ-w, HuoG-sheng. Thermodynamic analysis and potential-pH diagrams of Li-Co-H₂O system [J]. Chinese Journal of Power Source, 2005, 29(7): 423-426(in Chinese)

[23] GuoC-h, ZhaoZ-wei. Thermodynamic analysis on Li-Ni-H₂O system [J]. Chinese Journal of Power Source, 2005, 29(6): 7-10

[24] DeanJ ALang’s handbook of chemistry [M], 19873rd edSingapore, McGRAW-Hill

[25] SongS, HanK, SasagawaI, WatanabeT, YoshimuraM. Effect of LiOH concentration change on simultaneous preparation of LiCoO₂ film and powder by hydrothermal method [J]. Solid State Ionics, 2000, 135(1-4): 277-281

[26] ChenY-x, LiY-j, LiW, CaoG-l, TangS-y, SuQ-y, DengS-y, GuoJia. High-voltage electrochemical performance of LiNi_0.5Co_0.2Mn_0.3O₂ cathode material via the synergetic modification of the Zr/Ti elements [J]. Electrochimica Acta, 2018, 281: 48-59

[27] ZhuJ, LiY-j, XueL-l, ChenY-x, LeiT-x, DengS-y, CaoG-lin. Enhanced electrochemical performance of Li3PO4 modified Li[Ni_0.8Co_0.1Mn_0.1O₂ cathode material via lithium- reactive coating [J]. Journal of Alloys and Compounds, 2019, 773: 112-120