Li dendrites inhibition realized by lithiophilic and ion/electron conductive 3D skeleton for Li metal anodes

Abstract

• The Si layer is sputtered on the surface of Ti fibers by magnetron sputtering. • The STM electrodes exhibit good lithiophilicity and ion/electron conductivity. • Dendrite-free and smooth Li deposition is obtained on STM electrodes. • The STM@Li anodes deliver stable cycling in both symmetric and full cells. Li metal anode holds the key for further high-energy-density batteries. Inhibition of Li dendrites and superior electrochemical performance are critical for its practical application. Herein, a low-cost Si membrane with dual effects on 3D Ti mesh (STM) is designed through magnetron sputtering. The in situ formed Li-Si alloy layer presents highly lithiophilic and ion conductive, endowing lower nucleation barrier and homogeneous Li-ion flux, while the high electron conductive of 3D host with capacious voids immensely facilitates kinetics and relieves volume expansion. Consequently, a smooth Li layer looked like a “quilt” is uniformly formed instead of generating fair share of 1D Li whiskers. The constructed Li ‖ STM@Li symmetric cell keeps operating for 800 h at 2 mA cm −2 and 2 mAh cm −2 with a low overpotential of 25 mV. Even under carbonate-based electrolyte, the full cells using Li 1.2 Ni 0.13 Co 0.13 Mn 0.54 O 2 (LNCM) as cathode can deliver a high initial capacity (245 mAh g −1 ) and capacity retention (81.2%) after 100 cycles at 1 C.