Regenerable sodium-based lithium silicate sorbents with a new mechanism for CO_2 capture at high temperature

摘要

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. (C) 2018 Elsevier Ltd. All rights reserved.