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It was precisely because LiNi 0. 5 Mn 1. 5 O4 cathode material had many advantages, including high voltage, high power, no pollution, low cost, etc., that it became a research hotspot for lithium-ion cathode materials. Although LiNi 0. 5 Mn 1. 5 O4 has a three-dimensional Li + diffusion channel, there are still some problems that lead to capacity decay and reduced cycling stability, limiting its commercial application. In this paper, the LiNi 0. 5 Mn 1. 5 O4 cathode material was prepared by the freezing precipitation method. We studied the effects of different drying methods, such as blast drying, water bath drying and freeze-drying on the structure, morphology and electrochemical properties of LiNi 0. 5 Mn 1. 5 O4 cathode materials. The study found that the LiNi 0. 5 Mn 1. 5 O4 cathode material prepared by the precipitation-freeze-drying method had a complete crystal form, a stable structure and no LixNi 1 − x O impurity peak. The SEM image showed that the particles were smaller and had a smooth surface. The initial discharge-specific capacity at 0.1 C was 105.2 mAh⋅g − 1 . After 50 cycles, its specific discharge capacity was 99.4 mAh⋅g − 1 and the capacity retention rate was 94.5%. Compared with LiNi 0. 5 Mn 1. 5 O4 materials prepared by other methods, it had better electrochemical performance. [ABSTRACT FROM AUTHOR]

In order to enhance the corrosion resistance of calcium-based phosphate coating, the molybdenum-modified coating was successfully prepared by adding Na2MoO4 in a phosphate bath. The prepared composite film layers were studied by EDS, XRD and SEM. The corrosion resistance performances of the films were investigated by electrochemical measurements. The results showed the main composition of molybdenum-modified film was MoO2, MoP2, and MoP4, the diameter of cracks on the surface of the coating was significantly reduced, which provided better protection to the substrate. In addition, the potentiodynamic polarization curves of the molybdenum-modified film show that the corrosion potential was positively shifted by 0.068 V compared to the calcium-based phosphate coating and the corrosion current was reduced to 2.556 × 10 − 5 A · cm − 2 , indicating improved corrosion resistance. [ABSTRACT FROM AUTHOR]

LiNi0.5Co0.2Mn0.3O2 lithium-ion battery cathode material is considered to be one of the most promising cathode materials for development. The co-precipitation-freeze-drying method was used to add K+ to the materials to investigate the changes in the microstructure as well as the electrochemical properties of the materials. Specifically, K+-doped LiNi0.5Co0.2Mn0.3O2 cathode materials were successfully synthesized by the co-precipitation-freeze-drying method, and the prepared Li KxNi0.5Co0.2Mn0.3O2 materials were well-distributed and exhibited excellent electrochemical properties. Providing an initial discharge capacity of 189.26 mA h g–1 capacity retention of 66.66%, 100 cycles of 2.5–4.8 V and a current density of 0.1 C. The good electrochemical performance of the material may be attributed to the increased lattice spacing of the material with the addition of K+, which enlarges the channels for lithium ion insertion and detachment, further accelerating its diffusion rate. [ABSTRACT FROM AUTHOR]

The application of LiNi0.5Co0.2Mn0.3O2 is still hindered by its low capacity retention rate and poor high rate performance. The surface coating has proven to be an effective strategy to solve these problems. However, the previous surface coating method will make the synthesis process more complicated. In this work, a simple organic salt decomposition method is developed to prepare LiNi0.5Co0.2Mn0.3O2@Cu cathode material (NCM@Cu). The results of the scanning electron microscope (SEM), X-ray diffractometer (XRD), and energy X-ray spectroscopy (EDS) have confirmed that a uniform copper-coated composite structure has been successfully constructed without changing the crystal structure. Charge and discharge tests show that the irreversible capacity loss of NCM@Cu at 0.2 C is 33.8 mA h g–1, which is lower than NCM. Compared with bare NCM, the composite cathode NCM@Cu has better cycle performance. This improvement is attributed to the coating of the copper element, which increases surface electron transport. [ABSTRACT FROM AUTHOR]

LiNi0.5Co0.2Mn0.3O2 (NCM523) cathode materials are susceptible to irreversible phase changes and surface side reactions between electrode materials and electrolyte during charging and discharging, which represent a severe danger to the safety and electrochemical performance of batteries. Li NaxNi0.5Co0.2Mn0.3O Cly cathode materials co-doped with Na+ and Cl– were prepared by a simple co-precipitation method. The effects of crystal structure, morphology and electrochemical properties were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and charge-discharge performance tests. The results show that the doping of Na+ and Cl– reduces the mixing of cations and expands the diffusion channels of Li+. Currently, the doped 1%-NCM has a high charge-discharge capacity and the best cycling performance (187.56 mA h g–1 at 1 C with the highest capacity retention at 76.29% after the first cycle). After 50 cycles, the specific capacity retention was 138.33 mA h g–1, which increased the capacity retention by 18.58% compared with the unmodified material, indicating that the co-doping of anions and cations improved the Li+ de-embedding ability as well as the specific capacity. [ABSTRACT FROM AUTHOR]

High-voltage LiNi0.5Mn1.5O4 cathode material has attracted much more attention. In this work, spherical LiNi0.5Mn1.5O4 (LNMO-S) cathode material has been successfully prepared via surfactant-assisted co-precipitation method with sodium dodecyl sulfate (SDS) as a surfactant. Influence of SDS addition on the morphology and electrochemical performance of LiNi0.5Mn1.5O4 cathode materials were investigated. The results showed that LNMO-S cathode material prepared via surfactant-assisted co-precipitation method had ranking electrochemical performance; the initial discharge capacity was 135.5 mAh·g−1, over 100 cycles the discharge capacity with the capacity retentiveness was 96.9% at a rate of 0.2 C, the discharge capacities were 120.2 mAh·g−1, 116.4 mAh·g−1, and 96.7 mAh·g−1 at the rate of 1.0 C, 2.0 C, and 5.0 C, respectively. It had a well rate performance and stability. It is exhibited that surfactant-assisted co-precipitation method with SDS as surfactant is a promising technology to preparate of LiNi0.5Mn1.5O4 cathode materials for lithium-ion battery. [ABSTRACT FROM AUTHOR]

The Mo-doped LiNi0.5Mn1.5O4 material has been successfully synthesized by the freezing precipitation method, and the effect of different doping amounts on the properties of LiNi0.5Mn1.5O4 material has been studied. Texting has included XRD, SEM, first charge and discharge curves, cycle performance, rate cycle, CV analysis, and EIS analysis. The experimental results show that the Mo-doping material shows superior performance when the doping amount is 1%, and this amount ensures the highest capacity of the sample. The capacity is 120.1 mAh g−1 at 0.1 C (initial discharge), with which the particle size and the dispersion are uniform. After 50 cycles, the discharge capacity is 118.3 mAh g−1 at 0.1 C, and the capacity retention rate is 98.5%. These results reveal that Mo-doped LiNi0.5Mn1.5O4 contributes to the outstanding electrochemical performance of the LiNi0.5Mn1.5O4. [ABSTRACT FROM AUTHOR]