The effects of Ni doping on the performance of O3-lithium manganese oxide material

Li_0.7[Li_1/6Mn_5/6]O₂ and Li_0.7[Li_1/12Ni_1/12Mn_5/6]O₂ powders were synthesized by a sol-gel method. The powders had a typically rhombohedral layered O₃ structure. Both the samples were nanometer-sized powders and the size of Li_0.7[Li_1/12Ni_1/12Mn_5/6]O₂ was smaller than that of Li_0.7[Li_1/6Mn_5/6]O₂. The discharge curve shape of both the sample electrodes was almost equal to that of the layered structure. However, the electrode materials were transferred from layered to spinel structures with increasing the cycle number. Li/Li_0.7[Li_1/6Mn_5/6]O₂ and Li_0.7[Li_1/12Ni_1/12Mn_5/6]O₂ cells initially delivered a discharge capacity of 261 and 238 mAh/g, respectively. The capacities of Li/Li_0.7[Li_1/6Mn_5/6]O₂ and Li_0.7 [Li_1/12Ni_1/12Mn_5/6]O₂ after the 45th cycle were 174 and 221 mAh/g, respectively, corresponding to the retentions of 67% and 93%. The nanostructure of the synthesized powders seems to result in high initial discharge capacity as well as in the suppression of the discharge capacity fading by providing high surface area needed for Li ion reaction. In Ni doped-Li_0.7[Li_1/12Ni_1/12Mn_5/6]O₂, the capacity fading was reduced by suppressing the oxidation state of Mn from 4⁺ to 3⁺ due to the role of Ni ion doped.     

The effects of Ni and Li doping on the performance of lithium manganese oxide material for lithium secondary batteries

Layered Li_0.7[M_1/6Mn_5/6]O₂ (M=Li, Ni) was synthesized using a sol-gel method. P2-Na_0.7[M_1/6Mn_5/6]O₂ precursor was first synthesized by a sol-gel method, and then O2-Li_0.7[M_1/6Mn_5/6]O₂ was prepared by an ion exchange of Li for Na in P2-Na_0.7[M_1/6Mn_5/6]O₂ precursor. From charge/discharge curves, it was seen that Li_0.7[Li_1/6Mn_5/6]O₂ has two plateaus similar to those observed from a spinel structure, but Li_0.7[Ni_1/6Mn_5/6]O₂ holds a single plateau as observed from a typical layered structure. It was considered that Li_0.7[Li_1/6Mn_5/6]O₂ undergoes a phase transformation from layered to spinel structure during the charge/discharge cycle, but Li_0.7[Ni_1/6Mn_5/6]O₂ maintains O2-layered structure after the cycles. Li_0.7[Ni_1/6Mn_5/6]O₂ was higher in discharge capacity and retention rate than Li_0.7[Li_1/6Mn_5/6]O₂.     

Structural and electrochemical characteristics of Li0.7[Li1/6Mn5/6]O2 synthesized using sol-gel method

Layered O₂-lithium manganese oxide (O₂-Li_0.7[Li_1/6Mn_5/6]O₂) was prepared by ion-exchange of P2-sodium manganese oxide (P2-Na_0.7[Li_1/6Mn_5/6]O₂)· P2-Na_0.7[Li_1/6Mn_5/6]O₂ precursor was first synthesized by using a sol-gel method, and then O₂-Li_0.7[Li_1/6Mn_5/6]O₂ was produced by an ion exchange of Li for Na in the P2-Na_0.7[Li_1/6Mn_5/6]O₂ precursor. Structural and electrochemical analyses suggested that good quality O2-Li_0.7[Li_1/6Mn_5/6]O₂ was prepared from P2-Na_0.7[Li_1/6Mn_5/6]O₂ synthesized at 800 °C for 10 h using glycolic acid as a chelating agent. During the cycle, the discharge profile of the synthesized samples showed two plateaus at around 4 and 3 V, respectively, with a steep slope between the two plateaus. The discharge curve at 3 V escalated with an increase in the cycle number, presenting a phase transition from a layered to a spinel like structure. The sample prepared at 800 ‡C for 10 h using glycolic acid delivered a discharge capacity of 187 mAh/g with small capacity fading.     

High-rate, high capacity ZrO2 coated Li[Li1/6Mn1/2Co1/6Ni1/6]O2 for lithium secondary batteries

Recently, there have been many reports on efforts to improve the rate capability and discharge capacity of lithium secondary batteries in order to facilitate their use for hybrid electric vehicles and electric power tools. In the present work, we present a ZrO₂-coated Li[Li_1/6Mn_1/2Co_1/6Ni_1/6]O₂. The bare Li[Li_1/6Mn_1/2Co_1/6Ni_1/6]O₂ shows a high initial discharge capacity of 224 mAh g⁻¹ at a 0.2 C rate. Owing to the stability of ZrO₂, it was possible to enhance the rate capability and cyclability. After 1 wt% ZrO₂ coating, the ZrO₂-coated Li[Li_1/6Mn_1/2Co_1/6Ni_1/6]O₂ showed a high discharge capacity of 115 mAh g⁻¹ after 50 cycles under a 6 C rate, whereas the bare Li[Li_1/6Mn_1/2Co_1/6Ni_1/6]O₂ showed a discharge capacity of only 40 mAh g⁻¹ and very poor cyclability under the same conditions. Based on results of XRD and EIS measurements, it was found that the ZrO₂ suppressed impedance growth at the interface between the electrodes and electrolyte and prevented collapse of the layered hexagonal structure.     

Synthesis and electrochemical properties of Li[Li0.07Ni0.1Co0.6Mn0.23]O2 as a possible cathode material for lithium-ion batteries

The layered Li[Li_0.07Ni_0.1Co_0.6Mn_0.23]O₂ materials were synthesized by sol-gel method with glycine or citric acid as chelating agent. The prepared materials were characterized by means of XRD, SEM and Raman spectroscopy. Li/Li[Li_0.07Ni_0.1Co_0.6Mn_0.23]O₂ cells were assembled and subjected to charge-discharge studies at different C rates, viz 0.2, 1, 2 and 4 C. Although the samples showed less discharge capacity at 4 C rate the fade in capacity per cycle is lesser than that of capacity fade at 0.2 C rate. The citric acid assisted sample is found to be superior in terms of discharge capacity, capacity retention rate and also in thermal stability to that of sample prepared with glycine as chelating agent.     

Ultrathin CeO2 coating for improved cycling and rate performance of Ni-rich layered LiNi0.7Co0.2Mn0.1O2 cathode materials

In this study, we have successfully coated the CeO₂ nanoparticles (CeONPs) layer onto the surface of the Ni-rich layered LiNi_0.7Co_0.2Mn_0.1O₂ cathode materials by a wet chemical method, which can effectively improve the structural stability of electrode. The X-ray powder diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM), and X-ray photoelectron spectroscopy (XPS) are used to determine the structure, morphology, elemental composition and electronic state of pristine and surface modified LiNi_0.7Co_0.2Mn_0.1O₂. The electrochemical testing indicates that the 0.3?mol% CeO₂-coated LiNi_0.7Co_0.2Mn_0.1O₂ demonstrates excellent cycling capability and rate performance, the discharge specific capacity is 161.7?mA?h?g^?1 with the capacity retention of 86.42% after 100 cycles at a current rate of 0.5?C, compared to 135.7?mA?h?g^?1 and 70.64% for bare LiNi_0.7Co_0.2Mn_0.1O₂, respectively. Even at 5?C, the discharge specific capacity is still up to 137.1?mA?h?g^?1 with the capacity retention of 69.0%, while the NCM only delivers 95.5?mA?h?g^?1 with the capacity retention of 46.6%. The outstanding electrochemical performance is assigned to the excellent oxidation capacity of CeO₂ which can oxidize Ni²⁺ to Ni³⁺ and Mn³⁺ to Mn⁴⁺ with the result that suppress the occurrence of Li⁺/Ni²⁺ mixing and phase transmission. Furthermore, CeO₂ coating layer can protect the structure to avoid the occurrence of side reaction. The CeO₂-coated composite with enhanced structural stability, cycling capability and rate performance is a promising cathode material candidate for lithium-ion battery.     

Particle size effect of Li[Ni0.5Mn0.5]O2 prepared by co-precipitation

Spherical (Ni_0.5Mn_0.5)(OH)₂ with different secondary particle size (3 μm, 10 μm in diameter) was synthesized by co-precipitation method. Mixture of the prepared hydroxide and lithium hydroxide was calcined at 950 °C for 20 h in air. X-ray diffraction patterns revealed that the prepared material had a typical layered structure with space group. Spherical morphologies with mono-dispersed powders were observed by scanning electron microscopy. It was found that the layered Li[Ni_0.5Mn_0.5]O₂ delivered an initial discharge capacity of 148 mAh g⁻¹ (3.0-4.3 V) though the particle sizes were different. Li[Ni_0.5Mn_0.5]O₂ having smaller particle size (3 μm) showed improved area specific impedance due to the reduced Li⁺ diffusion path, compared with that of Li[Ni_0.5Mn_0.5]O₂ possessing larger particle size (10 μm). Although the Li[Ni_0.5Mn_0.5]O₂ (3 μm) was electrochemically delithiated to Li_0.39[Ni_0.5Mn_0.5]O₂, the resulting exothermic onset temperature was around 295 °C, of which the value is significantly higher than that of highly delithiated Li_1−δCoO₂ (∼180 °C).     

Stabilizing the structure and suppressing the voltage decay of Li[Li0.2Mn0.54Co0.13Ni0.13]O2 cathode materials for Li-ion batteries via multifunctional Pr oxide surface modification

The development of Li-rich layer cathode materials has been limited by poor cycle, rate performance, phase transformation and voltage decay. To improve these properties, a facile and low-cost wet method is employed to fabricate Pr₆O₁₁ coating layer on Li[Li_0.2Mn_0.54Co_0.13Ni_0.13]O₂ nanoparticles. The 3–6 nm Pr₆O₁₁ coating layer is observed on the surface of Li[Li_0.2Mn_0.54Co_0.13Ni_0.13]O₂ by HRTEM. Interestingly, HAADF-STEM and EDS analyses show that the transition metal ions and the praseodymium ions mutually infiltrate in the Pr₆O₁₁ coating layer and Li[Li_0.2Mn_0.54Co_0.13Ni_0.13]O₂ nanoparticles during calcination. A combination of HAADF-STEM with EDS and XPS studies reveals that Pr₆O₁₁ coating layer is bridged to Li[Li_0.2Mn_0.54Co_0.13Ni_0.13]O₂ nanoparticles by the chemical bonds of transition phase Li_1.2M_XPr_1−xO₂. XRD patterns show that all samples are indexed to the layered structure α-NaFeO₂, but the lattice parameters are influenced lightly after Pr₆O₁₁ coating. HRTEM and SAED analyses elucidate that the super large Pr ions surface-doping and the Pr₆O₁₁ coating are verified to suppress the transformation of layer to spinel structure in the bulk nanoparticles after cycles. The sample coated with 3 wt% Pr₆O₁₁ exhibits wonderful electrochemical performance with the first coulomb efficiency of 85.6%, the capacity retention ratio of 97.9% after 50 cycles and the discharge capacity of 162.2 mAh g⁻¹ at 5 C. The resistant of charge transfer and the electrodes polarization are reduced by Pr₆O₁₁ coating according to EIS. Therefore, Pr₆O₁₁, which contains the super large Pr ions, plays two roles: the first one, it is coated on the Li[Li_0.2Mn_0.54Co_0.13Ni_0.13]O₂ nanoparticles to optimize the environment of the interface reaction between electrodes and electrolyte; the other one, its Pr ions surface-doping stabilizes the structure in the superficial region of Li[Li_0.2Mn_0.54Co_0.13Ni_0.13]O₂ nanoparticles and suppresses the voltage decay. The multifunctional Pr₆O₁₁ can play a significant role in accelerating development of new materials with excellent stabilization and high capacity.     

Electrochemical properties of layered Li[Ni1/2Mn1/2]O2 cathode material synthesised by ultrasonic spray pyrolysis

Layered Li[Ni_1/2Mn_1/2]O₂ was synthesized by an ultrasonic spray pyrolysis method. The Li[Ni_1/2Mn_1/2]O₂ powder was characterized by means of X-ray diffraction, charge/discharge test, and cyclic voltammetry. The discharge capacity increases linearly with increase of the upper cut-off voltage limit and attains a high discharge capacity of 187 mA h g^–1 between 2.8 and 4.6 V with excellent cyclability. A cyclic voltammetric study of the Li[Ni_1/2Mn_1/2]O₂ electrode showed only one redox peak implying no structural phase change during cycling.     

Electrochemical and thermal studies of Li[NixLi(1/3−2x/3)Mn(2/3−x/3)]O2 (x = 1/12, 1/4, 5/12, and 1/2)

Samples of the layered cathode materials, Li[Ni_xLi_(1/3−2x/3)Mn_(2/3−x/3)]O₂ (x = 1/12, 1/4, 5/12, and 1/2), were synthesized at 900 °C. Electrodes of these samples were charged in Li-ion coin cells to remove lithium. The charged electrode materials were rinsed to remove the electrolyte salt and then added, along with EC/DEC solvent or 1 M LiPF₆ EC/DEC, to stainless steel accelerating rate calorimetry (ARC) sample holders that were then welded closed. The reactivity of the samples with electrolyte was probed at two states of charge. First, for samples charged to near 4.45 V and second, for samples charged to 4.8 V, corresponding to removal of all mobile lithium from the samples and also concomitant release of oxygen in a plateau near 4.5 V. Li[Ni_xLi_(1/3−2x/3)Mn_(2/3−x/3)]O₂ samples with x = 1/4, 5/12 and 1/2 charged to 4.45 V do not react appreciably till 190 °C in EC/DEC. Li[Ni_xLi_(1/3−2x/3)Mn_(2/3−x/3)]O₂ samples charged to 4.8 V versus Li, across the oxygen release plateau, start to significantly react with EC/DEC at about 130 °C. However, their high reactivity is similar to that of Li_0.5CoO₂ (4.2 V) with 1 μm particle size. Therefore, Li[Ni_xLi_(1/3−2x/3)Mn_(2/3−x/3)]O₂ samples showing specific capacity of up to 225 mAh/g may be acceptable for replacing LiCoO₂ (145 mAh/g to 4.2 V) from a safety point of view, if their particle size is increased.     

Effect of synthesis condition on the structural and electrochemical properties of Li[Ni1/3Mn1/3Co1/3]O2 prepared by the metal acetates decomposition method

In order to get homogeneous layered oxide Li[Ni_1/3Mn_1/3Co_1/3]O₂ as a lithium insertion positive electrode material, we applied the metal acetates decomposition method. The oxide compounds were calcined at various temperatures, which results in greater difference in morphological (shape, particle size and specific surface area) and the electrochemical (first charge profile, reversible capacity and rate capability) differences. The Li[Ni_1/3Mn_1/3Co_1/3]O₂ powders were characterized by means of X-ray diffraction (XRD), charge/discharge cycling, cyclic voltammetry and SEM. XRD experiment revealed that the layered Li[Ni_1/3Mn_1/3Co_1/3]O₂ material can be best synthesized at temperature of 800 °C. In that synthesized temperature, the sample showed high discharge capacity of 190 mAh g⁻¹ as well as stable cycling performance at a current density of 0.2 mA cm⁻² in the voltage range 2.3-4.6 V. The reversible capacity after 100 cycles is more than 190 mAh g⁻¹ at room temperature.     

On the LiCo2/3Ni1/6Mn1/6O2 positive electrode material

LiCo_2/3Ni_1/6Mn_1/6O₂ layered oxide was synthesized by the combustion method that led to a crystalline phase with good homogeneity and low particles size. The structural properties of the prepared positive electrode material were investigated by performing XRD Rietveld refinement. Practically no Li/Ni mixing was detected evidencing that the studied compound adopts almost an ideal α-NaFeO₂ type structure. The Li||LiCo_2/3Ni_1/6Mn_1/6O₂ cell showed a discharge capacity of 199 mAh g⁻¹ when cycled in the 2.7–4.6 V potential range while the best cycling performances were recorded when the upper cut off is fixed at 4.5 V. Structural changes in Li_xCo_2/3Ni_1/6Mn_1/6O₂ with lithium electrochemical de-intercalation were studied using X-ray diffraction. This study clearly shows the existence of a solid solution domain in the 0.1 < x < 1.0 composition range while for x = 0.1, a new phase appears explaining the decrease of the electrochemical performance when the cell is cycled at high upper cut off voltage.     

Synthesis optimization of Li1 + x[Mn0.45Co0.40Ni0.15]O2 with different spherical sizes via co-precipitation

Li_1 + x[Mn_0.45Co_0.40Ni_0.15]O₂ spherical cathode materials with different sizes (about 2 and 5 μm) were fabricated by calcining uniform spherical metal carbonate, [Mn_0.45Co_0.40Ni_0.15]CO₃ with lithium hydroxide at high temperature. The precursor of spherical metal carbonate, [Mn_0.45Co_0.40Ni_0.15]CO₃, was obtained via co-precipitation method at room temperature, which was significantly dependent on synthetic conditions, such as the reaction temperature, the concentration of NH₄HCO₃, and stirring speed, etc. The optimized condition resulted in [Mn_0.45Co_0.40Ni_0.15]CO₃, of which the particle size distribution was uniform and the particle shape was spherical. The final products, Li_1 + x[Mn_0.45Co_0.40Ni_0.15]O₂, had a well-ordered layered structure and uniform homogeneity. Raman spectroscopy analysis showed the Raman-active species E_g and A_1g modes were observed at 488, 473 cm^− 1 and 597, 590 cm^− 1, respectively, for the obtained spherical cathode materials.     

Synthetic optimization of spherical Li[Ni1/3Mn1/3Co1/3]O2 prepared by a carbonate co-precipitation method

A carbonate co-precipitation method was employed to prepare spherical Li[Ni_1/3Co_1/3Mn_1/3]O₂ cathode material. The precursor, [Ni_1/3Co_1/3Mn_1/3]CO₃, was prepared using ammonia as chelating agent under CO₂ atmosphere. The spherical Li[Ni_1/3Co_1/3Mn_1/3]O₂ was prepared by mixing the precalcined [Ni_1/3Co_1/3Mn_1/3]CO₃ with LiOH followed by high temperature calcination. The preparation conditions such as ammonia concentration, co-precipitation temperature, calcination temperature and Li/[Ni_1/3Co_1/3Mn_1/3] ratio were varied to optimize the physical and electrochemical properties of the prepared Li[Ni_1/3Co_1/3Mn_1/3]O₂. The structural, morphological, and electrochemical properties of the prepared LiNi_1/3Co_1/3Mn_1/3O₂ were characterized by XRD, SEM, and galvanostatic charge-discharge cycling. The optimized material has a spherical particle shape and a well ordered layered structure, and it also has an initial discharge capacity of 162.7 mAh g^− 1 in a voltage range of 2.8-4.3 V and a capacity retention of 94.8% after a hundred cycles. The optimized ammonia concentration, co-precipitation temperature, calcination temperature, and Li/[Ni_1/3Co_1/3Mn_1/3] ratio are 0.3 mol L^− 1, 60 °C, 850 °C, and 1.10, respectively.     

Characterization of high tap density Li[Ni1/3Co1/3Mn1/3]O2 cathode material synthesized via hydroxide co-precipitation

Li[Ni_1/3Co_1/3Mn_1/3]O₂ cathode material for lithium ion batteries was prepared by mixing metal hydroxide, (Ni_1/3Co_1/3Mn_1/3)(OH)₂, with 6% excess LiOH followed by calcinations. The (Ni_1/3Co_1/3Mn_1/3)(OH)₂ with secondary particle of about 12 μm was prepared by hydroxide co-precipitation. The tap density of the obtained Li[Ni_1/3Co_1/3Mn_1/3]O₂ powder was 2.56 ± 0.21 g cm⁻³. The powder was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), particle size distribution (PSD) and galvanostatic charge-discharge cycling. The XRD pattern of Li[Ni_1/3Co_1/3Mn_1/3]O₂ revealed a well ordered hexagonal layered structure with low cation mixing. Secondary particles with size of 13-14 μm and primary particles with size of about 1 μm can be identified from the SEM observations. In the voltage range of 2.8-4.3 V, the initial discharge capacity of the Li[Ni_1/3Co_1/3Mn_1/3]O₂ electrode was 166.6 mAh g⁻¹, and 96.5% of the initial capacity was retained after 50 charge-discharge cycling.     

Synthesis and structural characterization of layered Li[Ni1/3Co1/3Mn1/3]O2 cathode materials by ultrasonic spray pyrolysis method

The layered Li[Ni_1/3Co_1/3Mn_1/3]O₂ materials were synthesized by a spray pyrolysis method using citric acid as a polymeric agent. The Li[Ni_1/3Co_1/3Mn_1/3]O₂ powders were characterized by means of X-ray diffraction (XRD), charge/discharge cycling, cyclic voltammetry, and high-resolution transmission electron microscopy (TEM). The discharge capacity increases linearly with the increase of the upper cut-off voltage limit. TEM analysis showed that particles in the as-prepared powder possessed a polycrystalline structure. During cycling, the particle structure is mostly preserved although some surface grains on the polycrystalline particle became separated and transformed to the spinel phase.     

Enhanced electrochemical performance of O3-type Li0.6[Li0.2Mn0.8]O2 for lithium ion batteries via aluminum and boron dual-doping

An O3 type Li_0.6[Li_0.2Mn_0.8]O₂ lithium-rich material has a high reversible capacity due to the synergistic oxidation and reduction of anion and cation. However, the anion oxidation reaction that compensates the charge leads to a partial release of oxygen and the collapse of the structure inevitably. Here, we improve the structural stability of Li_0.6[Li_0.2Mn_0.8]O₂ by simultaneously introducing Al ions and B ions. Al ions and B ions randomly occupy octahedral and tetrahedral positions, hindering the migration of Mn ions and expanding the unit cell, resulting in a stable structure and promoting Li⁺ migration. The co-doped sample has better electrochemical performance than the bare material, and the capacity retention increases from 62.48% to 82.48% after 80 cycles at 0.1C rate, and still provides a capacity of 226 mAh g⁻¹ between 2 and 4.8 V.     

Electrochemical properties and structural characterization of layered Li[Ni0.5Mn0.5]O2 cathode materials

Layered Li[Ni_0.5Mn_0.5]O₂ materials with high homogeneity and crystallinity were prepared using high speed ball milling. The Li[Ni_0.5Mn_0.5]O₂ electrode delivered a high discharge capacity of 152 mA h g⁻¹ between 2.8 and 4.3 V with excellent cycleability. The TEM analysis showed that the Li[Ni_0.5Mn_0.5]O₂ electrode went through a considerable morphological change without altering its initial layered structure while the electrode retained its initial discharge capacity even after 50 cycles.     

The first cycle characteristics of Li[Ni1/3Co1/3Mn1/3]O2 charged up to 4.7 V

In this research, we studied the first cycle characteristics of Li[Ni_1/3Co_1/3Mn_1/3]O₂ charged up to 4.7 V. Properties, such as valence state of the transition metals and crystallographic features, were analyzed by X-ray absorption spectroscopy and X-ray and neutron diffractions. Especially, two plateaus observed around 3.75 and 4.54 V were investigated by ex situ X-ray absorption spectroscopy. XANES studies showed that the oxidation states of transition metals in Li[Ni_1/3Co_1/3Mn_1/3]O₂ are mostly Ni²⁺, Co³⁺ and Mn⁴⁺. Based on neutron diffraction Rietveld analysis, there is about 6% of all nickel divalent (Ni²⁺) ions mixed with lithium ions (cation mixing). Meanwhile, it was found that the oxidation reaction of Ni²⁺/Ni⁴⁺ is related to the lower plateau around 3.75 V, but that of Co³⁺/Co⁴⁺ seems to occur entire range of x in Li_1−x[Ni_1/3Co_1/3Mn_1/3]O₂. Small volume change during cycling was attributed to the opposite variation of lattice parameter “c” and “a” with charging-discharging.     

Novel high-capacity hybrid layered oxides NaxLi1.5-xNi0.167Co0.167Mn0.67O2 as promising cathode materials for rechargeable sodium ion batteries

Relatively low capacity is a technological bottleneck of the development of sodium ion batteries. Herein, we present a series of hybrid layered cathode materials Na_xLi_1.5-xNi_0.167Co_0.167Mn_0.67O₂ (x?=?0.5, 0.6, 0.7, 0.8, 0.9, 1) with composite crystalline structures, which are prepared by co-precipitation method. The combined analysis of XRD, SEM and TEM reveals that the materials are composed of P2 structure, α-NaFeO₂ structure and small amount of Li₂MnO₃. Among the as-prepared materials, Na_0.6Li_0.9Ni_0.167Co_0.167Mn_0.67O₂ delivers an initial reversible capacity of 222?mA?h?g^?1 at 20?mA?g^?1. Even at 100?mA?g^?1, it shows a remarkable discharge capacity of 125?mA?h?g^?1 in the first cycle and remains 60?mA?h?g^?1 after 300 cycles. Such high capacity is achieved by the specific composite structure and sodium ions are proved to be able to intercalate/deintercalate in Li_1.5Ni_0.167Co_0.167Mn_0.67O₂ with α-NaFeO₂ structure. The Ex-situ XRD results of Na_0.6Li_0.9Ni_0.167Co_0.167Mn_0.67O₂ in the first cycle show that the P2 structure is well maintained along with irreversible phase transition of α-NaFeO₂ structure, which is responsible for the long-term capacity fading. Owing to the high discharge capacity, the novel hybrid layered oxides Na_xLi_1.5-xNi_0.167Co_0.167Mn_0.67O₂ with composite structures can be considered as promising cathode materials to promote progress toward sodium-ion batteries.