Bonded β 12-borophene/hybrid honeycomb–kagome silicene heterostructure: A high-capacity anode with robust structural stability for Na-ion batteries

The development of next-generation energy storage systems critically demands anode materials with exceptional ion storage capacity and structural robustness. Bonded heterostructures offer distinct advantages over conventional two-dimensional (2D) monolayers by synergistically stabilizing lattice frameworks through interfacial interactions. 2D hybrid lattices composed of honeycomb and kagome structures have garnered significant attention due to their unique geometries and tailored electronic states. Herein, via first-principles calculations, we propose a strongly bonded β12-borophene (β12-B)/hybrid honeycomb–kagome silicene (hhk-Si) heterostructure as a high-performance anode for lithium/sodium-ion batteries (LIBs/SIBs). This bonded configuration exhibits superior structural stability compared to van der Waals counterparts, as evidenced by machine learning-accelerated ab initio molecular dynamics simulations spanning an extended 100 ps timeframe. The heterostructure demonstrates intrinsic structural robustness during multi-ion intercalation, coupled with stable adsorption sites featuring ultralow diffusion barriers (Li: 0.35 eV; Na: 0.20 eV). Notably, the predicted maximum sodium storage capacity reaches 1823 mAh/g, outperforming both monolayers and most 2D heterostructures. These findings suggest that the proposed β12-B/hhk-Si is a promising anode for SIBs and paves the way for kagome–honeycomb hybrid lattices in energy storage applications.