The effects of sodium hexametaphosphate (SHMP) addition on the dispersion and hydration of calcium aluminate cement were investigated, and the relevant mechanisms discussed. The content of SHMP and the adsorption capacity of SHMP on the surface of cement particles were estimated using plasma adsorption spectroscopy and the residual concentration method. The rheological behavior of hydrate, ζ-potential value of cement particles, phase transformation and the microstructure of the samples were determined by coaxial cylinder rheometer, zeta probe, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results indicate that SHMP readily reacted with Ca²⁺, forming complexes [Ca₂(PO₃)₆]²⁻ ions which were subsequently adsorbed onto the surfaces of cement particles. When the content of SHMP was 0.05%, the adsorption ratio reached 99%. However, it decreased to 89% upon further increasing the addition of SHMP to 0.4%. The complexes [Ca₂(PO₃)₆]²⁻ adsorbed onto the surfaces of cement particles inhibited the concentration of Ca²⁺ and changed ζ-potential, resulting in enhanced electrostatic repulsive force between the cement particles and reduced viscosity of cement-water slurry. The experimental results indicate that the complexes [Ca₂(PO₃)₆]²⁻ covering the surfaces of cement particles led to a delayed hydration reaction, i.e., they extended the hydration time of the cement particles, and that the optimal addition of SHMP was found to be about 0.2%.

Ion doping can modify the cell structure, which is one of the effective methods to improve electrochemical performance. However, there is a lack of research on F- and Cl-doped LiNi_0.8Co_0.1Mn_0.1O₂. In this paper, the effects of F and Cl doping on the electrochemical properties and cell structure of LiNi_0.83Co_0.08Mn_0.08O₂ during the process of lithium removal were studied by a first-principles calculation based on density functional theory. The results show that F doping reduces the change in cell parameters and improves the stability of cell structure. On the contrary, Cl doping reduces the stability of the cell structure. F doping increased the delithiation potential from 3.64 V to 3.76 V, and the delithiation potential was relatively stable in the process of delithiation. Cl doping decreased the delithiation potential from 3.64 V to 3.26 V, and the voltage stability became worse. F doping can effectively reduce the occurrence of Li–Ni mixed arrangement phenomena. Meanwhile, Cl doping can inhibit the formation of oxygen vacancies, and the further degradation of the materials. F doping broadens the Li⁺ diffusion channel away from the doping site and improves the diffusion rate of Li⁺ in this layer. In the vicinity of F-doped sites, the electrostatic field in the process of Li⁺ diffusion is enhanced and the diffusion of Li⁺ is reduced. Cl doping increases the diffusion barrier of Li⁺ and slows down the diffusion rate of Li⁺.