Regenerable sodium-based lithium silicate sorbents with a new mechanism for CO2 capture at high temperature

Recently, lithium-ion batteries have become widespread as a source of power or energy for everything from portable electronics to electric vehicles. As a result, the consumption of lithium is rapidly increasing, accompanied by an increase in its price. This study reports the synthesis of a regenerable sodium-based lithium silicate solid sorbent that uses less lithium than Li4SiO4 solid sorbents. The regenerable sodium-based lithium silicate solid sorbent was prepared by mixing LiOH with a sodium silicate solution in a 2:1 M ratio, which steadily maintained its CO2 capture capacity during multiple cycles. In addition to Li4SiO4 present in the developed solid sorbent, we attribute CO2 sorption and regeneration to a new structure, namely Li3NaSiO4. Notably, the LONS2 solid sorbent exhibits a faster CO2 sorption rate than that of the Li4SiO4 sorbent. Moreover, the LONS2 solid sorbent containing both Li3NaSiO4 and Li4SiO4 phases has potential for CO2 capture at high temperature.