Practical deployment of Li₄SiO₄ as a high-temperature CO₂ sorbent requires pelletization, which inevitably densifies the microstructure and imposes severe CO₂ diffusion limitations. Conventional sacrificial pore-forming agents address this issue but remain single-purpose, serving solely as structural templates without conferring chemical benefits. Here, we demonstrate that spent coffee grounds (SCG), an abundant food-industry waste, can serve as a single-source modifier that achieves three co-localized enhancements in Li₄SiO₄ pellets: hierarchical pore engineering, in-situ K-doping, and oxygen vacancy generation. The thermal decomposition of SCG creates an interconnected hierarchical macroporous network that effectively reduces intraparticle CO₂ diffusion resistance. Meanwhile, the mineral-rich SCG ash provides in-situ potassium doping, generating a localized eutectic molten carbonate phase that accelerates liquid-phase ion transport. Crucially, the transient reducing atmosphere during biomass combustion introduces oxygen vacancies into the silicate lattice; Density Functional Theory (DFT) calculations reveal that these vacancies serve as highly active CO₂ adsorption sites with a strongly exothermic adsorption energy of −0.914 eV. Benefiting from this triple-synergistic enhancement, the SCG-modified sorbent (LSO-50) achieves a CO₂ adsorption capacity of 0.275 g/g at 650 °C under 15 vol% CO₂, representing a more than fourfold improvement over unmodified pellets. When further combined with Na₂CO₃ co-doping to promote additional eutectic formation, the optimized sorbent (LSON-50) reaches 0.330 g/g, retains 0.284 g/g after 50 adsorption–desorption cycles, and exhibits robust mechanical stability (<10% attrition loss). By co-locating structural, chemical, and defect features within a single biomass-derived modifier, this work establishes a scalable waste-valorization route for high-performance, eco-friendly CO₂ capture.

Investigating the dynamic mechanical behavior of single-crystal aluminum oxynitride (AlON) is fascinating and crucial for understanding material performance in relevant applications. Nevertheless, few studies have explored the dynamic mechanical properties of AlON single crystals. In this study, a series of nanoimpact experiments (representative strain rate ${\dot{\epsilon }}_{\text{r}}\text{≈}{\text{10}}^{\text{2}}{\text{s}}^{-\text{1}}$) were performed on three principal orientations ((010), (101), and (111)) of grains to extract the dynamic mechanical responses of AlON single crystals. Our results reveal that the dynamic plasticity of an AlON single crystal is governed by a combination of mechanisms, including dislocation motion and amorphization. Significantly, the localized amorphization induced by mechanical deformation has a softening effect (a lower dynamic hardness). The crystallographic orientation affects the dynamic hardness similarly to the static hardness. In particular, the (111) orientation results in the highest hardness, whereas the (010) orientation is the softest among the three principal orientations. This dependency aligns with the expectations derived from applying Schmid law. Furthermore, both the dynamic and static hardnesses exhibit typical indentation size effects (ISEs), which can be effectively described via the strain gradient theory associated with the geometrically necessary dislocations. In addition, the size and rate dependencies of the dynamic hardness can be decoupled into two independent terms.