(2) Coating the material particles with electrochemically inert materials to prevent or suppress the side reactions between the cathode surface and electrolyte, and improve the particles' structural stability for enhancing the cycle-life of the corresponding LIBs. (1) Element doping for improving the cationic mixing and lattice stability, such as doping Mg, Al, Zr, and other components into materials to improve the cycling performance ( Nobili et al., 2012 Min et al., 2017). There are mainly two methods to improve the performance of high-nickel NCM-based materials. In recent years, many improvements have been carried out for high-nickel NCM-based materials of LIB cathodes, including innovating the synthesis processes, doping modification, and matching of microstructure with electrolyte. The nickel element in the NCM-based material is alkaline, which is easy to absorb water and CO 2 when exposed to air and reacts with residual lithium in the surface layer to form LiOH and Li 2CO 3, which can further increase the pH value of the material and seriously affect the electrochemical performance of the NCM-based material ( Bi et al., 2016). Furthermore, the high-valent active transition metal ions on the surface layer can have side reactions with the electrolyte, causing the increase of polarization and then the decay of the capacity ( Noh et al., 2006). The excessive delithiation occurs in the surface structure with charging, and the layered structure of the high-nickel NCM-based material changes to the spinel structure and the inert rock salt structure with a hicker inert NiO layer. Studies have shown that the higher the nickel content in the ternary material, the worse the thermal stability, causing safety issue ( Aurbach, 2000 Ma et al., 2019). The voltage stability of the material is also relatively weak, which is easy to decline rapidly ( Noh et al., 2013 Li et al., 2019 Zhang et al., 2019). Furthermore, during the charging process, the low-valence nickel ion in the transition metal (Co, Mn) layer can migrate to the lithium layer, occupying the lithium vacancies, affecting the diffusion of Li +. In high-nickel NCM-based material, part of Ni 2+ may occupy the Li + position, forming a cation mixing and then reducing the specific capacity of material. (1) Li +/Ni 2+ mixing when Ni 2+ content is increased. In general, for high-nickel NCM-based materials, there are several shortcomings which have been identified. It seems that one of the most promising LIB cathode materials is LiNi 0.8Co 0.1Mn 0.1O 2 (NCM811, where x = 0.8, y = 0.1, and z = 0.1), which shows higher specific capacity than other family members ( Cao et al., 2018 Li Q. In order to further increase energy densities of the devices, high-nickel NCM-based materials such as LiNi xCo yMn zO 2 (here x+y+z = 1 with x>y+z) family have been explored and used in LIBs. For relatively mature lithium-ion batteries (LIBs), the cathode materials play a dominating role in the performance of LIBs. Therefore, the surface coating to the particles of cathode materials using LBO is expected to be an effective and practical modification method to improve the electrochemical performance of LIBs.Įlectrochemical energy technologies, such as lithium-ion batteries, metal-air batteries, fuel cell, and water electrolysis, etc., have been recognized as one type of the most reliable and efficient options for clean and sustainable electricity energy storage and conversion ( Khan et al., 2018 Wang et al., 2018 Zhang H. The experiment results confirm that the charge-discharge specific capacity, Coulomb efficiency, water absorption stability, cycle characteristics, and resistance stability of the NCM811 cathode material can be significantly improved by coating it with LBO particularly. Coin LIBs are assembled with the uncoated, Al 2O 3-coated, ZrO 2-coated, and LBO-coated NCM811 cathode materials for performance validation. The effects of Al 2O 3, ZrO 2, and LBO thin coating layers (~20–200 nm) on the morphology, structure and electrochemical property of NCM811 are studied using XRD, SEM, TEM, XPS, and electrochemical measurements. To improve the performance of this NCM811 material, Al 2O 3, ZrO 2, and LBO (Li 2O-2B 2O 3) are, respectively, used to coat it by a wet chemical method. By mixing this material with LiOH in proportion and sintering twice under 500 and 800☌, respectively, the cathode material of LiN i0.8Co 0.1Mn 0.1O 2 (NCM811) for lithium ion batteries (LIBs) is synthesized. In this paper, the precursor Ni 0.8Co 0.1Mn 0.1(OH) 2 is prepared by a co-precipitation method. 2Institute for Sustainable Energy/College of Sciences, Shanghai University, Shanghai, China.1Department of Physics, College of Sciences, Shanghai University, Shanghai, China.Hailin Zhang 1 Jiaqiang Xu 2 Jiujun Zhang 2 *

Xps lialo2 coating on nmc cathode