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Corresponding Author

Li-Juan Li(lilijuan@gotion.com.cn)

Abstract

In this paper, the phase transformation voltage ranges of two layered oxide ternary cathode materials, namely, Li(Ni0.85Co0.10Mn0.05)O2 (referred to Ni85, presenting high Ni content) and Li(Ni0.6Co0.2Mn0.2)O2 (referred to Ni60, presenting common low Ni content), were classified and determined. The structural differences between high Ni and common low Ni ternary materials were studied in order to understand the structure instability of high nickel material during the charging process. At the same time, the differential capacity (dQ·dV-1) curves of Ni85 and Ni60 positive electrodes during the charging process were obtained to characterize phase regions, and the corresponding relationship between the cathode and anode phase transfermations was studied. In addition, the phase transformation and surface morphology of Ni85 and Ni60 materials were analyzed by X-Ray diffraction (XRD) and field emission scanning electron microscopy (SEM). It is concluded that the high Ni positive electrode underwent three phase transformations of H1→M→H2→H3 within the normal charging range of 3.0 V ~ 4.2 V, through which the final product was H3 phase, which is relatively unstable. In the same charging voltage range, the traditional Ni60 material only experienced the phase transition from H1 phase to M phase. When overcharged to 4.550 V, Ni60 material could reach H2 phase, and after overcharging to 5.000 V, H3 phase transformation could be completed. The dQ·dV-1 curve reflects the above phase transformation processes, and the variations of characteristic diffraction peaks can be observed on XRD. The cross section SEM images of fresh and fully charged cathodes showed that, the particle crushing degree of Ni85 material was obviously greater than that of Ni60 material under the full charge state. According to the above experimental results, it can be concluded that the H3 phase transformation could be completed within the normal charging voltage range for Ni85 material. Therefore, the lower phase transformation voltage threshold of high Ni material accounts mainly for the poor structure stability.

Graphical Abstract

Keywords

lithium-ion batteries, high-Ni layered oxide cathodes, phase transitions

Publication Date

2021-08-28

Online Available Date

2020-11-03

Revised Date

2020-07-14

Received Date

2020-06-16

References

[1] Hua W B, Wang S N, Knapp M, Leake S J, Senyshyn A, Richter C, Yavuz M, Binder J R, Grey C P, Ehrenberg H, Indris S, Schwarz B. Structural insights into the formation and voltage degradation of lithium-and manganese-rich layered oxides[J]. Nat. Commun., 2019, 10(1): 5365-5375.
doi: 10.1038/s41467-019-13240-z URL

[2] Yang J, Xia Y Y. Suppressing the phase transition of the layered Ni-rich oxide cathode during high-voltage cycling by introducing low-content Li2MnO3[J]. ACS Appl. Mater. Interfaces, 2016, 8(2): 1297-1308.
doi: 10.1021/acsami.5b09938 URL

[3] De Biasi L, Schiele A, Roca-Ayats M, Garcia G, Brezesinski T, Hartmann P, Janek J. Phase transformation behavior and stability of LiNiO2 cathode material for Li-ion batteries obtained from in situ gas analysis and operando X-ray diffraction[J]. ChemSusChem, 2019, 12(10): 2240-2250.
doi: 10.1002/cssc.v12.10 URL

[4] Liu W, Oh P, Liu X, Lee M J, Cho W, Chae S, Kim Y, Cho J. Nickel-rich layered lithium transition-metal oxide for high-energy lithium-ion batteries[J]. Angew. Chem. Int. Ed., 2015, 54(15): 4440-4457.
doi: 10.1002/anie.201409262 URL

[5] Ryu H H, Park N Y, Yoon D R, Kim U H, Yoon C S, Sun Y K. New class of Ni-rich cathode materials Li[NixCoyB1-x-y]O2 for next lithium batteries[J]. Adv. Energy Mater., 2020, 10(25): 2000495.
doi: 10.1002/aenm.v10.25 URL

[6] Dose W M, Piernas-Muñoz M J, Maroni V A, Trask S E, Bloom I, Johnson C S. Capacity fade in high energy silicon-graphite electrodes for lithium-ion batteries[J]. Chem. Comm., 2018, 54(29): 3586-3589.
doi: 10.1039/C8CC00456K URL

[7] Yan B G, Liu J C, Song B H, Xiao P F, Lu L. Li-rich thin film cathode prepared by pulsed laser deposition[J]. Sci. Rep., 2013, 3(1): 3332-3336.
doi: 10.1038/srep03332 URL

[8] Wang S H, Li Y X, Wu J, Zheng B Z, McDonald M J, Yang Y. Toward a stabilized lattice framework and surface structure of layered lithium-rich cathode materials with Ti modification[J]. Phys. Chem. Chem. Phys., 2015, 17(15): 10151-10159.
doi: 10.1039/C5CP00853K URL

[9] Shen C H, Huang L, Lin Z, Shen S Y. Kinetics and structural changes of Li-rich layered oxide 0.5Li2MnO3·0.5LiNi0.292Co0.375Mn0.333O2 material investigated by a novel technique combining in situ XRD and a multipotential step[J]. ACS Appl. Mater. Interfaces, 2014, 6(15): 13271-13279.
doi: 10.1021/am503132t URL

[10] Liu N(柳娜). Investigation of high temperature cycling performance for NCM811/graphite battery[J]. Chin. Battery Ind.(电池工业), 2017, 21(1): 4-8.

[11] Ma H Y(马洪运), Yao X H(姚晓辉), Miao M Y(妙孟姚), Yi Y(易阳), Wu S Z(伍绍中), Zhou J(周江). Degradation mechanism of LiNi0.83Co0.12Mn0.05O2 cycled at 45℃[J]. J. Electrochem.(电化学), 2020, 26(3): 431-440.

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