Modification for Li4SiO4 through Solid-State Reaction

https://doi.org/10.3390/ijms20040928

“It is clear that Li₄SiO₄ material synthesized by the solid-state reaction method from SiO₂ and Li₂CO₃ achieves low CO₂ absorption capacity, due to the low porosity of Li₄SiO₄ generated at high temperatures during the preparation. Thus, the CO₂ absorption capacity of Li₄SiO₄ decreases rapidly with the number of cycles, which is the main disadvantage of Li₄SiO₄ material in industrial applications. The various methods have been reported to enhance the cyclic performance of Li₄SiO₄ material prepared by solid-state reaction method, such as hydration [33] and ball milling [34,35]. The strategies to enhance the cyclic performance of Li₄SiO₄ can be categorized as follows: (i) reducing the diffusion resistance by adding solid solutions or molten salts; (ii) using alternative precursors; and (iii) using a more appropriate synthesis method.”

“As discussed above, high temperature during the preparation by the solid-state reaction method of Li₄SiO₄ leads to sintering, and the core of Li₄SiO₄ usually cannot react with CO₂. Thus, Yin et al. [33] proposed a hydration process to improve the pore structure of Li₄SiO₄ material. First, Li₄SiO₄ material was prepared by the solid-state reaction method, and then distilled water was added to the samples and stirred at 80 °C for 4 h. They reported that dense particles formed during the solid-state reaction preparation could be split into fine particles, so the porous structure and high cyclic CO₂ absorption capacity of Li₄SiO₄ was obtained by hydration process.