Droplet-Directed Anisotropic Assembly of Semifootball-Like Carbon Nanoparticles with Multimodal Pore Architectures

Abstract

Hierarchical porous carbon nanoparticles, with tailored asymmetric morphologies and pore structures, have great implications in high-performance electrode materials. However, the controlled synthesis of anisotropic carbon nanoparticles with tailored multimodal pore structures remains a challenge. Herein, a droplet-directed anisotropic assembly approach to synthesize asymmetric carbon nanoparticles with macro/mesopores is demonstrated. This synthesis relies on the anisotropic growth of mesoporous polydopamine (PDA) seeds on the emulsion interfaces and the subsequent immersion of 1,3,5-trimethylbenzene (TMB) droplets into the seeds. The obtained carbon nanoparticles present a semifootball-shaped morphology with a high surface area (383 m² g⁻¹), well-controlled macropores (≈105 nm), and mesopores (≈3.8 nm). By tuning the polarity of the oil phase, the morphologies transform from non-porous spheres to semifootball-like architectures and finally to nano-ellipsoid with meso-channels. The pore structures are further optimized by ZnCl₂ activation, and the semifootball-like carbon nanoparticles with modulated pore compositions deliver a high reversible capability, excellent rate performance (215 F g⁻¹ at 0.05 A g⁻¹ and 143 F g⁻¹ at 20 A g⁻¹ in organic electrolyte), and enhanced energy density (53.4 Wh Kg⁻¹). Simulation results elucidate the structure–activity relationship between the multistage pore structure and electrochemical performance, i.e., pore hierarchy enhances ion diffusion flux, and large-mesopore structure facilitates rate performance.