Lithium orthosilicate (Li₄SiO₄) represents a potential class of high-temperature sorbents for CO₂ capture in power plants and sorption enhanced methane reforming to produce H₂. However, conventional wisdom suggests that pure Li₄SiO₄ should have extremely slow sorption kinetics at realistic low CO₂ concentrations. Here, we report the opposite result: using a simple and cost-effective glucose-based mild combustion procedure, an unusually efficient and pure form of Li₄SiO₄ (MC-0.6) was synthesized to achieve a maximum uptake capacity of 35.0 wt.% at 580 °C for CO₂ concentrations under 15 vol.% and maintained this capacity over multiple cycles. The characterization results showed that highly porous nano-agglomerate-like (50-100 nm) morphologies were apparent and ensured a rapid surface-sorption of CO₂. In this process, a macroporous nano-sized Li₂SiO₃ cover on the melt layer of Li₂CO₃ was identified for the first time. This special structure appeared to accelerate the transportation of CO₂ and the diffusion of Li⁺ and O^2- through a molten layer enhancing contact with CO₂. Thus, the sample MC-0.6 reduced both the surface-sorption and diffusion kinetics dependence on low CO₂ concentrations. Rather than use traditional approaches (controlled morphologies combined with doping), we have demonstrated that the slow kinetics can be overcome simply by a controlled morphologies strategy, which opens up a new direction for the synthesis of high-performance Li₄SiO₄ sorbents.