To compare the effects of aluminum and manganese elements on the cycle performance of high-nickel cathode materials and further determine the differences in cycling stability and degradation mechanisms of nickel-cobalt-aluminum (NCA), nickel-cobalt-manganese (NCM), and nickel-cobalt-manganese-aluminum (NCMA), three common NCA, NCM, and NCMA high-nickel cathode materials with the same nickel content were chosen to study their similarities and differences of the cycle performance and the structural changes. The outcomes show that the three high-nickel cathode materials' cycle performance under room temperature is in the order of NCA>NCMA>NCM. Additionally, discovered by differential capacity (dQ/dV) curve and scanning electron microscopy, the degree of structural damages of the three materials at the same stage is in the order of NCM>NCMA>NCA, and the capacity decay of the battery during cycling is primarily caused the structural damages of the cathode materials. More study was performed on the cathode materials by electrochemical impedance spectroscopy at various cycle stages. It was discovered that the impedance of the cathodes continued to increase during cycling, and the impedance increase was influenced by the modifications in the crystal and the secondary particle structures. The discrepancies in the cycle performance of the three high-nickel cathode materials would ultimately be caused because the cycle stability of the cells is directly tied to the structural stability of the cathode materials. Systematic comparison and analysis of the cycle performance of NCA, NCMA, and NCM are helpful to deepen the understanding of the composition-structure-performance relationship of high-nickel content cathode materials, and it is of great significance for improving their cycle stabilities.
Fig. 1
Capacity retention rate curves of the three batteries during cycling (the capacity retention rate curves fluctuate due to factors such as the power outage of the incubator during the test)
Fig. 2
Ratio of recoverable capacity and non-recoverable capacity at small rate, as well as total loss of (a) NCA, (b) NCMA and (c) NCM battery during cycle process
图9
NCA正极循环首次循环与循环28次后充电过程与放电过程中 c 轴长度(原位XRD精修计算结果)对比
Fig. 9
The c-axis lengths (in-situ XRD refinement calculation results) during (a) charging process and (b) discharging process of NCA cathode before cycling and after cycling 28 times
MYUNG S T, MAGLIA F, PARK K J, et al. Nickel-rich layered cathode materials for automotive lithium-ion batteries: Achievements and perspectives[J]. ACS Energy Letters, 2017, 2(1): 196-223.
MANTHIRAM A, SONG B H, LI W D. A perspective on nickel-rich layered oxide cathodes for lithium-ion batteries[J]. Energy Storage Materials, 2017, 6: 125-139.
LIU W, OH P, LIU X E, et al. Nickel-rich layered lithium transition-metal oxide for high-energy lithium-ion batteries[J]. Angewandte Chemie (International Ed in English), 2015, 54(15): 4440-4457.
NOH H J, YOUN S, YOON C S, et al. Comparison of the structural and electrochemical properties of layered Li[NixCoyMnz]O2 (x=1/3, 0.5, 0.6, 0.7, 0.8 and 0.85) cathode material for lithium-ion batteries[J]. Journal of Power Sources, 2013, 233: 121-130.
YOON C S, CHOI M H, LIM B B, et al. Review—high-capacity Li[Ni1-xCox/2Mnx/2]O2(x=0.1, 0.05, 0) cathodes for next-generation Li-ion battery[J]. Journal of the Electrochemical Society, 2015, 162(14): doi: 10.1149/2.0101514jes.
XU C, REEVES P J, JACQUET Q, et al. Phase behavior during electrochemical cycling of Ni-rich cathode materials for Li-ion batteries[J]. Advanced Energy Materials, 2021, 11(7): doi: 10.1002/aenm.202003404.
SUN H H, MANTHIRAM A. Impact of microcrack generation and surface degradation on a nickel-rich layered Li[Ni0.9Co0.05Mn0.05]O2 cathode for lithium-ion batteries[J]. Chemistry of Materials, 2017, 29(19): 8486-8493.
LI H Y, LIU A, ZHANG N, et al. An unavoidable challenge for Ni-rich positive electrode materials for lithium-ion batteries[J]. Chemistry of Materials, 2019, 31(18): 7574-7583.
RYU H H, PARK K J, YOON C S, et al. Capacity fading of Ni-rich Li[NixCoyMn1-x-y]O2 (0.6≤x≤0.95) cathodes for high-energy-density lithium-ion batteries: Bulk or surface degradation?[J]. Chemistry of Materials, 2018, 30(3): 1155-1163.
ISHIDZU K, OKA Y, NAKAMURA T. Lattice volume change during charge/discharge reaction and cycle performance of Li[NixCoyMnz]O2[J]. Solid State Ionics, 2016, 288: 176-179.
HEENAN T M M, WADE A, TAN C, et al. Identifying the origins of microstructural defects such as cracking within Ni-rich NMC811 cathode particles for lithium-ion batteries[J]. Advanced Energy Materials, 2020, 10(47): doi: 10.1002/aenm.202002655.
ROMANO BRANDT L, MARIE J J, MOXHAM T, et al. Synchrotron X-ray quantitative evaluation of transient deformation and damage phenomena in a single nickel-rich cathode particle[J]. Energy & Environmental Science, 2020, 13(10): 3556-3566.
MANTHIRAM A, KNIGHT J C, MYUNG S T, et al. Nickel-rich and lithium-rich layered oxide cathodes: Progress and perspectives[J]. Advanced Energy Materials, 2016, 6(1): doi: 10.1002/aenm.201501010.
WATANABE S, KINOSHITA M, HOSOKAWA T, et al. Capacity fade of LiAlyNi1-x-yCoxO2 cathode for lithium-ion batteries during accelerated calendar and cycle life tests (surface analysis of LiAlyNi1-x-yCoxO2 cathode after cycle tests in restricted depth of discharge ranges)[J]. Journal of Power Sources, 2014, 258: 210-217.
KO D S, PARK J H, YU B Y, et al. Degradation of high-nickel-layered oxide cathodes from surface to bulk: A comprehensive structural, chemical, and electrical analysis[J]. Advanced Energy Materials, 2020, 10(36): doi: 10.1002/aenm.202001035.
LIU J L, DUAN Q L, MA M N, et al. Aging mechanisms and thermal stability of aged commercial 18650 lithium ion battery induced by slight overcharging cycling[J]. Journal of Power Sources, 2020, 445: doi: 10.1016/j.jpowsour.2019.227263.
DUBARRY M, TRUCHOT C, LIAW B Y. Synthesize battery degradation modes via a diagnostic and prognostic model[J]. Journal of Power Sources, 2012, 219: 204-216.
KEEFE A S, BUTEAU S, HILL I G, et al. Temperature dependent EIS studies separating charge transfer impedance from contact impedance in lithium-ion symmetric cells[J]. Journal of the Electrochemical Society, 2019, 166(14): doi: 10.1149/2.0541914jes.
LI J, HARLOW J, STAKHEIKO N, et al. Dependence of cell failure on cut-off voltage ranges and observation of kinetic hindrance in LiNi0.8Co0.15Al0.05O2[J]. Journal of the Electrochemical Society, 2018, 165(11): doi: 10.1149/2.0491811jes.
LIU H, WOLFMAN M, KARKI K, et al. Intergranular cracking as a major cause of long-term capacity fading of layered cathodes[J]. Nano Letters, 2017, 17(6): 3452-3457.
LING S G, WU J Y, ZHANG S, et al. Fundamental scientific aspects of lithium ion batteries(Ⅻ Ⅰ)——Electrochemical measurement[J]. Energy Storage Science and Technology, 2015, 4(1): 83-103.
SUN L M, ZHU L Z, HAN E S, et al. Effect of Mn content on the performance of Li(Ni0.9-xCo0.1Mnx)O2(x=0.1-0.3) cathode material for lithium ion batteries[J]. Chinese Journal of Power Sources, 2019, 43(9): 1423-1426.
LUO K, ROBERTS M R, HAO R, et al. Charge-compensation in 3d-transition-metal-oxide intercalation cathodes through the generation of localized electron holes on oxygen[J]. Nature Chemistry, 2016, 8(7): 684-691.
WANG B, ZHANG F L, ZHOU X A, et al. Which of the nickel-rich NCM and NCA is structurally superior as a cathode material for lithium-ion batteries?[J]. Journal of Materials Chemistry A, 2021, 9(23): 13540-13551.
LIN Q Y, GUAN W H, MENG J, et al. A new insight into continuous performance decay mechanism of Ni-rich layered oxide cathode for high energy lithium ion batteries[J]. Nano Energy, 2018, 54: 313-321.