Porous 3D Silicon‐Diamondyne Blooms Excellent Storage and Diffusion Properties for Li, Na, and K Ions

Abstract Regarding different kinds of alkali metal ion batteries such as lithium‐ion battery (LIB), sodium‐ion battery (NIB), and potassium‐ion battery (KIB), since the diameters and properties of these ions are different, there are few materials that are adaptable simultaneously as the anode for these batteries. To achieve the versatile compatibility material, its chemical component and spatial configuration need to be predesigned for possessing abundant storage sites and efficient diffusion paths. Here, a well‐designed 3D material silicon‐diamondyne (Si‐DY) is prepared which is only comprised of butadiyne units and sp³‐hybridized silicon atoms. Owing to the combination of the abundant diyne and various inner channels in the stable diamond‐like skeleton, Si‐DY exhibits excellent storage and diffusion properties for alkali metal ions. The Si‐DY is predicted with an ultrahigh theoretical capacity of 3674, 2810, and 1945 mAh g⁻¹ for lithium, sodium, and potassium ions, respectively. Especially, as the anode of LIB, NIB, and KIB, Si‐DY achieves very high stable practical specific capacities of 2350, 812, and 512 mAh g⁻¹, respectively, as well as an ultra‐long cycling stability. Those outstanding results demonstrate that the as‐designed Si‐DY displays an exceptional potential as the versatile material for energy applications.