Ternary nanoarray electrode with corn-inspired hierarchical design for synergistic lithium storage

Single-component anode materials can barely satisfy the growing demand for next-generation Li-ion batteries with higher capacity and cyclability. Thus developing multi-component synergistic electrodes has become a critical issue. Herein, inspired by natural corn, a ternary hierarchical self-supported array design is proposed. Based on a sequential transformation route, Si/C-modified Co₃O₄ nanowire arrays are constructed on 3D Ni foams to form a binder-free integrated electrode. Specifically, an ionic liquid-assisted electrodeposition strategy is employed to prepare discrete ultrafine Si nanoparticles on nanoscale array substrates, which follow the Volmer–Weber island growth mode. In this corn-mimetic system, kernel-like Si nanoparticles and a husk-like carbon coating layer function as enhancing and protecting units, respectively, to improve the capacity and stability of the cobalt oxide basic unit. Taking advantage of a synergistic effect, the ternary nanoarray anode achieves a significant performance enhancement compared to pristine Co₃O₄, showing a special capacity as high as ~1, 000 mAh·g⁻¹ at 100 mA·g⁻¹. By extending this corn-mimetic hierarchical array design to other basic, enhancing, and protecting units, new ideas for constructing synergistic nano-architectures for energy conversion and storage field are developed.