Due to its intriguing geometry, possessing an open-channel structure, Si-24 demonstrates potential for storing and/or transporting Li/Na ions in rechargeable batteries. In this work, first-principles calculations were employed to investigate the phase stability and Li/Na storage and transport properties of the Si-24 anode to evaluate its electrochemical performance for batteries. The intercalation of Li and Na into the Si-24 structure could deliver a capacity of 159 mA h g(-1) (Li4Si24 and Na4Si24), and the average intercalation potentials were 0.17 V (vs. Li) and 0.34 V (vs. Na). Moreover, the volume change of Si-24 upon intercalation proved very small (0.09% for Li, 2.81% for Na), indicating its zero-strain properties with stable cycling performance. Li+ and Na+ can diffuse along the channels inside the Si-24 structure with barrier energies of 0.14 and 0.80 eV respectively, and the ionic conductivity of Li2.66Si24 was calculated to be as high as 1.03 x 10(-1) S cm(-1) at 300 K. Our calculations indicate that the fast Li-ionic conductivity properties make the Si-24 structure a novel anode material for both lithium and sodium ion batteries.