Planar assembly of dual single-atom engineered mesoporous carbon onto Ti₃C₂T_x for high-energy lithium-ion batteries

Two-dimensional mesoporous carbon materials possessing dual structural advantages have shown great application potential in energy storage kingdom. However, the bottlenecks, such as low capacity and few active centers, have become their main obstacles for the large-scale applications. Herein, a facile planar assembly strategy has been developed to integrate heteroatoms-functionalized mesoporous carbon with bimodal pores onto Ti₃C₂T_x. Experimental results indicate that phytic acid serves as a multifunctional regulator during the assembly process. Its strong coordination ability with metal ions ensures the successful introduction of Fe/Co single atoms, while abundant hydroxyl groups enhance the robust anchoring effect of micelles onto Ti₃C₂T_x at the molecular level and facilitate the coexistence of spherical and cylindrical pores. Synchronous radiation and theoretical calculations verify that the highly dispersed metal single atoms with the FeN₄/CoN₄ configurations, coupled with a high nitrogen doping, significantly enhance the lithium-ion adsorption and storage sites. In-situ/ex-situ characterizations reveal that the bimodal mesopores effectively accelerate ion transport kinetics. The designed electrode exhibits an ultra-high lithium storage capability of 713.2 mA h g^-1 at 0.1 A g^-1 after 100 cycles. This work provides a promising universal strategy for developing other metal single atoms-doped mesoporous carbon electrode materials with high lithium storage capability.