Ni-rich lithium nickel manganese cobalt oxide cathode materials: A review on the synthesis methods and their electrochemical performances

Abstract

The demand for lithium-ion batteries (LIBs) has skyrocketed due to the fast-growing global electric vehicle (EV) market. The Ni-rich cathode materials are considered the most relevant next-generation positive-electrode materials for LIBs as they offer low cost and high energy density materials. However, by increasing Ni content in the cathode materials, the materials suffer from poor cycle ability, rate capability and thermal stability. Therefore, this review article focuses on recent advances in the controlled synthesis of lithium nickel manganese cobalt oxide (NMC). This work highlights the advantages and challenges associated with each synthesis method that has been used to produce Ni-rich materials. The crystallography and morphology obtained are discussed, as the performance of LIBs is highly dependent on these properties. To address the drawbacks of Ni-rich cathode materials, certain modifications such as ion doping, and surface coating have been pursued. The correlation between the synthesized and modified NMC materials with their electrochemical performances is summarized. Several gaps, challenges and guidelines are elucidated here in order to provide insights for facilitating research in high-performance cathode for lithium-ion batteries. Factors that govern the formation of nickel-rich layered cathode such as pH, reaction and calcination temperatures have been outlined and discussed.

Graphical abstract

Fig. 1

(a) The past and present applications of LIBs and future application projection of LIBs. Reprinted with permission from Ref. [8], Copyright 2021 Elsevier. (b) EVs battery cost breakdown [9].

Fig. 2

(a) Comparison of different types of cathodes [16], (b) adoption rate per chemistry in EV battery market [16] and (c) crystal structure of R-3m LiMO₂ layered oxide (M = Ni, Co, and Mn). Reprinted with permission from Ref. [12], Copyright 2021 AIP Publishing.

Fig. 3

SEM images of NMC622 samples α-NMC622 (a), α + β-NMC622 and (b), β-NCM622 (c), and (d) the cycle performance of prepared NMC 622. Reprinted with permission from Ref. [51], Copyright 2018 Elsevier.

Fig. 4

(a) XRD patterns of pristine NMC 811 and ZTO@NMC811, HRTEM images of (b), (c) lattice fringes, (d), (e) SAED pattern of ZTO@NMC811, (f) Charge-discharge profile of the first cycle at 0.1C, and (g) Cyclic performance of NMC 811 and ZTO@NMC811. Reprinted with permission from Ref. [63], Copyright 2023 Elsevier.

Fig. 5

Illustration of the comparison synthesis process of (a) NMC 811 by Lu et al. and (b) NMC 111 by Samanthan et al.

Fig. 6

FESEM images of the NMC 811 powders synthesized via (a) sol–gel and (b) co-precipitation, (c) the initial charge and discharge curves of NMC 811 synthesized via sol–gel (SG) and co-precipitation (CP). Reprinted with permission from Ref. [87], Copyright 2013 Elsevier. SEM images of the NMC 811 powders synthesized via (d) sol–gel and (e) co-precipitation. (f) rate cycling performance of NMC 111 electrode prepared by sol–gel, and co-precipitation methods at 1C. Reprinted with permission from Ref. [88], Copyright 2010 Elsevier.

Fig. 7

(a) XRD patterns of p-NMC811 and d-NMC811, (b) EDX spectrum of d-NMC811, charge-discharge profile at different cycle numbers of (c) p-NMC811, and (d) d-NMC811, (e) cycle performance, SEM images of (f) p-NMC811, and (g) d-NMC811. Reprinted with permission from Ref. [32], Copyright 2022 Elsevier.

Fig. 8

(a) Illustration of PVA/γ-Al₂O₃ coating process, (b) SEM image, (c) EDX mapping of aluminium, (f) TEM images of (d) pristine NMC 622, (e) PVA/γ-Al₂O₃ coated NMC 622, (f) first cycle capacity at 0.1 C, and (g) cycling performance at 0.5 C [39]. (h), (i) SEM images, and (j) TEM image of NMC- 2LLZO800, (k) first cycle capacity, and (l) cycling performance at 0.1 C. Reprinted with permission from Ref. [89], Copyright 2023 Elsevier.

Fig. 9

(a) Schematic illustration of synthesis of NMC622 by solid-state method, SEM images of NMC 622 (b) M1, (c) M2, and (d) M3. Reprinted with permission from Ref. [22], Copyright 2020 Elsevier. SEM images of NMC 811 calcined at (e) 750 °C, (f) 800 °C, and (g) 850 °C for 10 h. Reprinted with permission from Ref. [98], Copyright 2021 Wiley.

Fig. 10

(a) Schematic illustration of coating process of NMC 811 with HEO, (b) SEM images of HEO coated NMC 811, and (c) EDX mapping of the HEO coated NMC 811 [101]. (d) Schematic illustration of La-surface coating on NMC material, SEM images of (e) NMC, (f) 1 % La-coating, (g) 3 % La-coating, and (g) 5 % La-coating on NMC, HRTEM and corresponding FFT images of (i) 3 % La-coating on NMC after 100 cycles. Reprinted with permission from Ref. [102] Copyright 2020 Elsevier.

Fig. 11

(a) Charge/discharge curve at 0.1 C rate, (b) XRD patterns, and SEM images of samples sintered at (d) 750, (d) 800, and (e) 850 °C. Reprinted with permission from Ref. [30], Copyright 2020 Elsevier.

Fig. 12

XRD pattern of (a) LNCM and Na-LNCM, and Rietveld refinement of (b) LNCM (c) Na-LNCM sample. Reprinted with permission from Ref. [111], Copyright 2023 Elsevier.

Fig. 13

(a) XRD patterns of the NMC, LPO&NMC, H-LPO&NMC and Li₃PO₄, HRSEM images of (b) NMC, (c) LPO&NMC and (d) H-LPO&NMC, and (e) EDS mapping images. Reprinted with permission from Ref. [44], Copyright 2019 Elsevier.

Fig. 14

FESEM images of NMC622 sintered at (a) 700, (b) 800, (c) 900 and (d) 1000 °C; Charge-discharge curves at different current density of NMC 622 sintered at (e) 800 and (f) 900 °C; (g) Cyclic performance. Reprinted with permission from ref (Ahn et al., 2014), Copyright 2014 Elsevier.