Pristine LiNi0 Research Articles

Porous sphere-like LiNi0.5Mn1.5O4-CeO2 composite with high cycling stability as cathode material for lithium-ion battery

A new type of microsized porous spherical LiNi0.5Mn1.5O4-CeO2 cathode material composed of aggregated nanosized particles with P4332 space groups was prepared by an ethanol-assisted hydrothermal method. The nanosized particle shortens the Li+-ion diffusion path in the bulk LiNi0.5Mn1.5O4 and then improves the fast charge–discharge performance of this material. Moreover, a thin CeO2 layer with nanometer thickness on the surface of the LiNi0.5Mn1.5O4 particles is helpful for suppressing the interfacial side reactions. Because of these advantages, the LiNi0.5Mn1.5O4-CeO2 materials exhibit excellent electrochemical properties. Compared with the pristine LiNi0.5Mn1.5O4, LiNi0.5Mn1.5O4-CeO2 (3 wt%) exhibits outstanding discharge capacity, cycling stability and rate capability. LiNi0.5Mn1.5O4-CeO2 (3 wt%) delivers discharge capacities of 129.7, 121.2, 118.1, 109.8, and 86.3 mAh g−1 at 0.2, 0.5, 1, 2, and 5 C discharge rates, but the pristine one only delivers discharge capacities of 119.9, 103.7, 91.8, 84.7 and 34.4 mAh g−1 at the corresponding discharge rates. The introduction of CeO2 is a valid approach to enhance the electrochemical property of the LiNi0.5Mn1.5O4 material by forming an excellent electrical contact between CeO2 layer and LiNi0.5Mn1.5O4 surface, leading to an enhanced lithium-ion diffusion coefficient, reduced electrochemical polarization, and improved conductivity.

Spray drying assisted Combustion synthesis of LiNi0.45Mn1.45Co0.1O4/Graphene nanocomposite and its electrochemical properties

In this paper, we report the synthesis of of graphene- LiNi0.45Mn1.45Co0.1O4 hybrid cathode material using spray drying assisted combustion method. This method facilate the formation of homogenous nanoparticles. Further samples were characterised using X-ray diffraction (XRD), SEM, TEM, and Electrochemical Charge–Discharge. The results indicate the formation of cubic spinel phase LNMCO with average particle size of 48nm. Coating of graphene to LiNi0.45Mn1.45Co0.1O4 shows improved specific capacity of 118 mAh g−1 while pristine LiNi0.45Mn1.45Co0.1O4 has a capacity of 87 mAh g−1 at 0.1C rate. However we found that Graphene/ LiNi0.45Mn1.45Co0.1O4 is the promising cathode materials and spray drying method used for the synthesis can be extended to other electrode materials.

Preparation of Water-Resistant Surface Coated High-Voltage LiNi0.5Mn1.5O4 Cathode and Its Cathode Performance to Apply a Water-Based Hybrid Polymer Binder to Li-Ion Batteries

Water-resistant LiNi0.5Mn1.5O2 spinel cathode was prepared by surface coating with carbon, Al2O3 and Nb2O5 to use a water-based hybrid polymer (TRD202A, JSR, Japan) as a binder and to form the cathode film on an Al current collector. The surface composition and degree of the surface coverage of carbon, Al2O3 and Nb2O5 were characterized with field-emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The coated LiNi0.5Mn1.5O2 particles not only exhibited water-resistant property but also showed no decrease in discharge capacity and only a small degradation of discharge rate performance. In addition, the coated LiNi0.5Mn1.5O2 particles, that were exposed to water-based binder solution for one week, exhibited the same charge/discharge cycle performance as observed for the cathode of the pristine LiNi0.5Mn1.5O4 particles, suggesting that the coated particles are promising as cathode materials with a water-resistant property and therefore water can be used as solvent for preparing the cathode slurry solution in the place of e.g., carcinogenic N-methyl-2-pyrrolidone which is used actually.

Enhancing Electrochemical Performance of LiNi0.6Co0.2Mn0.2O2 by Lithium-ion Conductor Surface Modification

A novel surface modification strategy that could convert lithium residues on the Ni-rich material surface into a lithium ion conductor coating layer was investigated. Various analysis techniques, such as high resolution transmission electron microscopy (HRTEM), energy dispersive X-ray spectrometer (EDS) and X-ray photoelectron spectroscopy (XPS), were used to confirm the formation of an amorphous lithium lanthanum titanate (LLTO) coating layer with a thickness below 10nm. 1 mol% LLTO modified LiNi0.6Co0.2Mn0.2O2 exhibits the optimized electrochemical performance, with 87.2% capacity retention after 200 cycles at 0.5C, and excellent rate performance compared with that of the pristine LiNi0.6Co0.2Mn0.2O2. The cycling performance at higher charging voltage (4.5V) and storage characteristics against moisture and air are also improved significantly after LLTO modification. The enhanced electrochemical performance could be attributed to the high ionic conductivity of LLTO and the uniformity of the coating layer. It can not only suppress the interfacial resistance increasing, but also stabilize the crystal structure of the cathode material during charge-discharge cycling.

Enhanced electrochemical performance of Lithium Metasilicate-coated LiNi0.6Co0.2Mn0.2O2 Ni-rich cathode for Li-ion batteries at high cutoff voltage

Li2SiO3-coated LiNi0.6Co0.2Mn0.2O2 cathode material has been synthesized and exhibit much better electrochemical performance than pristine LiNi0.6Co0.2Mn0.2O2 at cut-off voltage 4.6V. The as-prepared samples are characterized by X-ray diffraction, field emission scanning electron microscopy, field emission transmission electron microscope, and X-ray photoelectron spectroscopic. The results show that the coating-layer Li2SiO3 is not incorporated into the LiNi0.6Co0.2Mn0.2O2 host structure and coated well on the surface of the active material. The sample coated with 3mol. % Li2SiO3 delivers a capacity of 168mAhg−1 at 0.2C after 100 cycles, and remains 85.5% of the first discharge capacity. The capacity retention at 1C is 73.6% after 100 cycles and the first discharge capacity reaches 158mAhg−1 at 10C. This superior performance is attributed to the coating layer which restrains the side reactions at electrode/electrolyte interface and enhances structure stability, meanwhile, it can decrease the electrode polarization because it is an excellent Li+-ion conductor.

Hydrothermal synthesis of reduced graphene oxide-LiNi0.5Mn1.5O4 composites as 5 V cathode materials for Li-ion batteries

Composite materials consisting of reduced graphene oxide and LiNi0.5Mn1.5O4 were in situ prepared by a simple one-step hydrothermal treating method. The physical property and electrochemical performance of the composite materials were characterized by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, cyclic voltammetry, charge/discharge testing, and electrochemical impedance spectroscopy. The results demonstrate that the graphene oxide is partially reduced and uniformly in situ anchored on the surface of LiNi0.5Mn1.5O4. As a result, the specific surface area of the composite material dramatically increases from 0.2488 to 8.71 m2 g−1, and the initial specific discharge capacity improves from 125.8 to 140.2 mAh g−1, respectively. Furthermore, the capacity retention maintains 95.8% after 100 cycles, and the electrode polarization has significantly been lessened. At rates of 1, 2, and 5 C, the composite material with 5% reduced graphene oxide can deliver much higher capacities than the pristine LiNi0.5Mn1.5O4. Moreover, AC impedance test results show that the interfacial charge transfer impedance obviously reduced. It is confirmed that the introduction of reduced graphene oxide through hydrothermal treating is effective to enhance the electrochemical performance of the composite material.

Silicon Doping of High Voltage Spinel LiNi0.5Mn1.5O4 towards Superior Electrochemical Performance of Lithium Ion Batteries

Si doping at high voltage spinel LiNi0.5Mn1.5O4 are presented as an effective strategy to greatly increase the electrochemical performance. Well-crystallized LiNi0.5Mn1.5-xSixO4 (x=0.05, 0.10, 0.15, 0.20) with homogeneous Si distribution are successfully synthesized through solid-state reaction. Structural and electrochemical characteristics are investigated through FESEM, XRD, FTIR, Raman spectroscopy, cyclic voltammetry and galvanostatic charge/discharge testing. It can be demonstrated that Si doping significantly improves the electrochemical performance. LiNi0.5Mn1.35Si0.15O4 exhibits reversible capacities of 123 mAh/g after the 100th cycle at 0.5C and LiNi0.5Mn1.35Si0.15O4 as well as LiNi0.5Mn1.3Si0.2O4 show superior electrochemical stability over the pristine LiNi0.5Mn1.5O4 material. Since the Si-O bond exhibits high dissociation energy of 798kJ/mol (298K), which is far beyond of the dissociation energies of the Mn-O or Ni-O bonds, the excellent electrochemical performance might be associated with an increased structural and chemical stability caused by incorporation of Si into the Oxygen-rich crystal lattice.

Improving the electrochemical performances of spherical LiNi0.5Mn1.5O4 by Fe2O3 surface coating for lithium-ion batteries

The spherical LiNi0.5Mn1.5O4 cathode material synthesized by a co-precipitation method has been modified by Fe2O3 through a simple chemical precipitation method. The effects of Fe2O3 coating on the structure and property of LiNi0.5Mn1.5O4 cathode have been carefully investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX) and atomic absorption spectroscopy (AAS). The results show that the Fe2O3 coating layer covered the surfaces of the spherical LiNi0.5Mn1.5O4 particles does not change the crystallographic structure of LiNi0.5Mn1.5O4, but it can protect the surface of the active materials from electrolyte erosion and suppresses the dissolution of transition metal elements. The effects of Fe2O3 coating layer on the electrochemical performances of LiNi0.5Mn1.5O4 have also been investigated systematically by the charge-discharge testing and AC impedance spectroscopy. Compared with the pristine LiNi0.5Mn1.5O4, the Fe2O3 modified material exhibits remarkably enhanced cyclic stability and excellent rate capability. In addition, surface modification of the LiNi0.5Mn1.5O4 is found to be an effective route for suppressing the increase of the impedance during the storage process at elevated temperatures.

Enhanced electrochemical performances of layered LiNi0.5Mn0.5O2 as cathode materials by Ru doping for lithium-ion batteries

The pristine and Ru-doped LiNi0.5Mn0.5O2 cathode materials are synthesized by a wet chemical method, followed by a high-temperature calcination process. The influence of Ru substitution on the microstructure and electrochemical performances of the prepared materials are investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and galvanostatic charge/discharge test. The XRD results show that, compared to the Ru-undoped sample, the LiNi0.5Mn0.45Ru0.05O2 owns a better hexagonal α-NaFeO2 structure and a smaller amount of cation mixing. The galvanostatic charge/discharge measurements demonstrate that the electrochemical properties of the LiNi0.5Mn0.5O2 sample are enhanced by Ru doping. At 5 and 10 C, the discharge capacity of LiNi0.5Mn0.45Ru0.05O2 is 118.61 and 105.43 mAh g−1, respectively, which is higher than those of LiNi0.5Mn0.5O2 (101.24 and 78.94 mAh g−1) due to the reduced charge-transfer resistance and the improved lithium-ion diffusion coefficient. On the basis of these results, Ru doping is considered an effective way to enhance the electrochemical performances of LiNi0.5Mn0.5O2 cathode materials.

Effect of Al substitution sites on Li1−xAlx(Ni0.5Co0.2Mn0.3)1−yAlyO2 cathode materials for lithium ion batteries

The effects of various Al concentration and substitution sites (including Li layer and transition metal layer) on the structural and electrochemical properties of LiNi0.5Co0.2Mn0.3O2 (NMC) materials are systematically investigated. X-ray diffraction, X-ray photoelectron spectroscopy and electrochemical tests confirm that LiAlO2 phase appears in Li1−xAlxNi0.5Co0.2Mn0.3O2 samples and contributes to better lithium ion diffusion coefficient. While Al prefer to form AlO solid solution in Li(Ni0.5Co0.2Mn0.3)1−yAlyO2 samples, which can improve the structural stability of NMC. As expected, Al substituted samples with suitable dopant concentration exhibit remarkably enhanced electrochemical performances compared with pristine LiNi0.5Co0.2Mn0.3O2. Particularly, the Li0.99Al0.01Ni0.5Co0.2Mn0.3O2 sample maintains 172.3 mAh g−1 (1 C) with 90.9% capacity retention after 100 high-voltage cycles at 4.6 V charge cut-off. These results demonstrate that substitution of Li with low Al content has superior advantages for LiNi0.5Co0.2Mn0.3O2 cathodes.

Study on the action mechanism of doping transitional elements in spinel LiNi0.5Mn1.5O4

Spinel LiNi0.5Mn1.5O4 is a very important and promising cathode material for lithium ion batteries. The strategy of doping elements is a common used way to improve its electrochemical properties. The action mechanism of doping elements in LiNi0.5Mn1.5O4 is complex. In this study, we synthesized the Cr, Fe-doped compounds LiNi0.45M0.1Mn1.45O4 (M=Cr, Fe) and pristine compound LiNi0.5Mn1.5O4 at the same annealing conditions. The as prepared samples display different morphological features. The thermogravimetric analysis shows different situation for these samples. Oxygen dissipation in the Cr-doped compound at high temperature is less than the other two samples. The XPS spectra display that the doping elements have influences on the chemical valence of Ni, and result in more Ni(III) amount in the Cr, Fe-doped products. The doped compounds exhibit excellent rate capability. At 10C-charge/10C-discharge rate, their capacities are 85mAhg−1, 74mAhg−1 and 50mAhg−1 for LiNi0.45Fe0.1Mn1.45O4, LiNi0.45Cr0.1Mn1.45O4 and LiNi0.5Mn1.5O4, respectively.

Influence of europium doping on the electrochemical performance of LiNi0.5Co0.2Mn0.3O2 cathode materials for lithium ion batteries

Pristine LiNi0.5Co0.2Mn0.3O2 and a series of Eu-doped LiNi0.5Co0.2Mn0.3O2 cathode materials have been successfully synthesized by a solid-state route. The influence of Eu doping on the crystal structure and electrochemical properties of LiNi0.5Co0.2Mn0.3O2 was evaluated by X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS), and galvanostatic charge–discharge tests. The results show that doping with Eu can expand the channels for diffusion of Li ion and reduce the charge transfer resistance. Furthermore, the 0.5mol% Eu-doped LiNi0.5Co0.2Mn0.3O2 exhibits an excellent rate capacity (122.00mAhg−1 at 3C) and cycling ability (139.99mAg−1 at 1C with a capacity retention of 96.93% after 50 cycles), which can be explained by the fact that doping with inactive Eu3+ ions may stabilize the crystal structure and expand the pathways for lithium ion diffusion.

Synthesis of Li2Si2O5-coated LiNi0.6Co0.2Mn0.2O2 cathode materials with enhanced high-voltage electrochemical properties for lithium-ion batteries

Ni-rich ternary layered oxides, (LiNix [M]1−xO2, x ≥ 0.5, M = Co and Mn), have become one of the mainstream cathode materials for next-generation lithium-ion batteries due to their high capacity and cost efficiency compared with LiCoO2. However, the high-voltage operation of the Ni-rich oxides (>4.3 V) required for high capacity is inevitably accompanied with a rapid capacity decay over numerous cycles. In this work, we reported a surface coating of LiNi0.6Co0.2Mn0.2O2 with Li2Si2O5via a facile and efficient synthetic approach, which involves the employment of silicic acid (H2SiO3) as remover to react with the surface residual lithium compounds (e.g. Li2CO3 and LiOH) of LiNi0.6Co0.2Mn0.2O2 and consequent formation of a robust and complete Li+-conductive Li2Si2O5 protective coating layer. The structure and morphology of the coated cathode materials are fully characterized by using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Compared with the pristine LiNi0.6Co0.2Mn0.2O2, coating with the Li+-conductive Li2Si2O5 is found to be very effective for improving the rate capability of the LiNi0.6Co0.2Mn0.2O2 when evaluated at a high cut-off voltage up to 4.5 V. Specifically, 1 wt. % H2SiO3-treated LiNi0.6Co0.2Mn0.2O2 electrode exhibits high discharge specific capacities of 213.9 and 121.6 mAh g−1 at 0.1 and 10 C, respectively, whereas the pristine electrode only shows 196.8 and 92.1 mAh g−1. Besides, the surface-modified LiNi0.6Co0.2Mn0.2O2 electrode also manifests an enhanced long-term cycling stability (67% capacity retention after 200 cycles at 5 C), much better than the pristine electrode (52% retention) due to the robust protective effect of the Li2Si2O5 coating layer. All these results indicate that the Li2Si2O5-coated LiNi0.6Co0.2Mn0.2O2 will be a promising cathode material for lithium-ion batteries with fascinating electrochemical energy storage capabilities.

A new coating for improving the electrochemical performance of cathode materials

The layered LiNi0.40Mn0.40Co0.20O2 compound was synthesized and modified with a mixed alumina–carbon coating by a simple soft chemical route. The simultaneous presence of alumina and carbon on the surface of coated samples was proved by ICP-AES, chemical analysis, XP spectroscopy, SEM microanalysis and local electron diffraction. For the first time, we show that the alumina epitaxial layer is formed on basal {001} facets of cathode grains, whereas side-view facets, like {010}, remain free from crystalline α-Al2O3, thus leaving them easy for Li-ion diffusion into cathode structure. An amorphous carbon film was used here for better conductivity of the coating layer and prevention of the electrical contact loss between cathode grains. Electrochemical tests revealed that the mixed alumina-carbon coating applied on LiNi0.40Mn0.40Co0.20O2 stabilizes the surface structure and improves the cycling performance (3–4.5 V) and rate capability of cathodes on their basis compared with the pristine and alumina-coated LiNi0.40Mn0.40Co0.20O2 samples.

Improved cycling performance of Li2MoO4-inlaid LiNi0.5Co0.2Mn0.3O2 cathode materials for lithium-ion battery under high cutoff voltage

Uniform spherical xLi2MoO4-inlaid LiNi0.5Co0.2Mn0.3O2 materials were successfully prepared through a solid state synthesis. To investigate the material characterization and electrochemical performance after Li2MoO4 modification, X-ray diffraction (XRD), Rietveld refinement, scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) mapping, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and electrochemical tests were applied. The results of the XRD, Rietveld refinement, SEM and EDS analyses showed that a Mo atom may be incorporated into the crystal lattice of the layer structure. Moreover, the presence of Li2MoO4 on the LiNi0.5Co0.2Mn0.3O2 surface was observed. The thickness of the Li2MoO4 coating layer on the xLi2MoO4-inlaid LiNi0.5Co0.2Mn0.3O2 material (x = 0.02) was approximately 25 nm. Similarly, XPS was performed to determine the effect of Li2MoO4 modification, confirming the presence of Li2MoO4. The xLi2MoO4-inlaid (x = 0.02) LiNi0.5Co0.2Mn0.3O2 materials exhibited a retention capacity 83.5% higher than that of the bare material (40.9%) after 200 cycles at 0.5 C between 3.0 and 4.4 V, and it also exhibited the best electrochemical properties at a cutoff voltage of 4.5 V. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) confirmed that the modification of Li2MoO4 plays an important role in improving the electrochemical performance of pristine LiNi0.5Co0.2Mn0.3O2.

Surface modification by sulfated zirconia on high-capacity nickel-based cathode materials for Li-ion batteries

Sulfated zirconia was successfully synthesized and uniformly coated onto a nickel-rich layered lithium oxide (LiNi0.8Co0.1Mn0.1O2), and investigated with a view to its potential use as a cathode material in Li-ion batteries. The uniformity of this sulfated zirconia coating was confirmed through electron microscopy, energy dispersive spectroscopy and Fourier transform infrared spectroscopy. Furthermore, the electrochemical properties of the sulfated-zirconia-coated LiNi0.8Co0.1Mn0.1O2 electrode were found to be greatly improved compared to those of pristine LiNi0.8Co0.1Mn0.1O2 and zirconia-coated LiNi0.8Co0.1Mn0.1O2, especially at elevated temperature (60 °C). These results are directly attributed to the sulfated zirconia coating, which is effective in reducing side reactions by preventing direct contact between the active materials and electrolyte solutions, as well as forming a more stable solid electrolyte interphase (SEI) layer on the active material surface.

Coating of spinel LiNi0.5Mn1.5O4 cathodes with SnO2 by an electron cyclotron resonance metal–organic chemical vapor deposition method for high-voltage applications in lithium ion batteries

Tin oxide coating by employing electron cyclotron resonance metal–organic chemical vapor deposition was performed on 5V-class spinel LiNi0.5Mn1.5O4 cathode electrodes prepared by a conventional tape-casting method. The pristine and SnO2-deposited LiNi0.5Mn1.5O4 electrodes were characterized by X-ray diffraction, field-emission electron probe microanalyzer, field-emission scanning electron microscopy, Auger electron spectroscopy, charge–discharge measurements, and electrochemical impedance spectroscopy were evaluated in lithium cells using the fabricated electrodes. The SnO2-deposited LiNi0.5Mn1.5O4 electrodes exhibited better rate capability at room temperature and superior electrochemical performance during the storage test evaluated at 60°C in a fully charged state than the pristine LiNi0.5Mn1.5O4 electrode. Also, surface modification of the LiNi0.5Mn1.5O4 electrode was found by impedance analyses to be effective for suppressing the increase of the charge transfer resistance during the storage test at elevated temperatures.

Improvement of electrochemical performance of LiNi0.8Co0.1Mn0.1O2 cathode material by graphene nanosheets modification

Layered LiNi0.8Co0.1Mn0.1O2-graphene composite is synthesized by a facile chemical approach and used as the cathode material for lithium-ion batteries. The structural and morphological features of as-prepared LiNi0.8Co0.1Mn0.1O2-graphene composite are investigated with powder X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy. The characterization results indicate that the LiNi0.8Co0.1Mn0.1O2 particles maintain their structural integrity and crystal features after being enwrapped with graphene nanosheets. The graphene-modified LiNi0.8Co0.1Mn0.1O2 comoposite exhibits superior electrochemical performance compared to the pristine LiNi0.8Co0.1Mn0.1O2 powders. The LiNi0.8Co0.1Mn0.1O2-graphene composite shows a large initial discharge capacity up to 212.9mAhg−1 as well as good cycling performance and good rate capability. The outstanding electrochemical performance of the graphene-modified LiNi0.8Co0.1Mn0.1O2 composite can be attributed to the improved electrical conductivity and structural stability due to the highly conductive graphene matrix.

Effect of surface Li3PO4 coating on LiNi0.5Mn1.5O4 epitaxial thin film electrodes synthesized by pulsed laser deposition

The effect of Li3PO4 coating was investigated for LiNi0.5Mn1.5O4 epitaxial thin film electrodes synthesized on SrTiO3 substrates by pulsed laser deposition (PLD). Amorphous Li3PO4 with a thickness of 1–4 nm was coated at room temperature onto 30 nm thick epitaxial LiNi0.5Mn1.5O4 thin films with (111), (110) and (100) lattice orientations. Electrodes with the surface coating exhibit high charge–discharge capacities and small capacity degradation during cycling experiments in the high voltage region. X-ray absorption near edge structure (XANES) and hard X-ray photoelectron spectroscopy (HAXPES) analyses indicate a higher manganese valence for the electrode surface of the Li3PO4 stacked LiNi0.5Mn1.5O4 film than that for the surface of a pristine LiNi0.5Mn1.5O4 film. Thus, surface coating affects the manganese valence near the electrode surface and improves the cycling characteristics.

Improve electrochemical performance of CeO2surface modification LiNi0.80Co0.15Al0.05O2cathode material

Lithium ion battery cathode material LiNi0.8Co0.15Al0.05O2 cathode has successfully prepared by co-precipitation. CeO2 surface modification has improved LiNi0.80Co0.15Al0.05O2 electrochemical performance use sol-gel method and subsequent heat treatment at 600 °C for 5 h. Different to other conventional coating material, CeO2 coating layer can not only inhibit the reaction of the electrode and the electrolyte, but also can reduce the impedance of electron transfer due to its high conductivity, and inhibit the production of Ni2+ because of its high oxidation. The surface-modified and pristine LiNi0.80Co0.15Al0.05O2 powders are characterized by XRD, SEM, TEM, XPS, CV and DSC. When CeO2 coating is 0.02% (mole ratio), contrast to pristine NCA, the CeO2-coated NCA cathode exhibits no decrease in its initial specific capacity of 184 mAh g −1 (at 0.2 C) and excellent capacity retention (86% of its initial capacity at 1 C) between 2.75 and 4.3 V after 100 cycles. The results indicate that the CeO2 surface treatment should be an effective way to improve cycle properties due to CeO2 inhibit the electrodes and the electrolyte side effects.