Roll-to-roll fabrication of lithiophilic Sn-modified Cu mesh via chemical tin plating approach for long-cycling lithium metal batteries

Abstract

Lithium metal, with its exceptionally high theoretical capacity, emerges as the optimal anode choice for high-energy-density rechargeable batteries. Nevertheless, the practical application of lithium metal batteries (LMBs) is constrained by issues such as lithium dendrite growth and low Coulombic efficiency (CE). Herein, a roll-to-roll approach is adopted to prepare meter-scale, lithiophilic Sn-modified Cu mesh (Sn@Cu mesh) as the current collector for long-cycle lithium metal batteries. The two-dimensional (2D) nucleation mechanism on Sn@Cu mesh electrodes promotes a uniform Li flux, facilitating the deposition of Li metal in a large granular morphology. Simultaneously, experimental and computational analyses revealed that the distribution of the electric field in the Cu mesh skeleton induces Li inward growth, thereby generating a uniform, dense composite Li anode. Moreover, the Sn@Cu mesh-Li symmetrical cell demonstrates stable cycling for over 2000 h with an ultra-low 10 mV voltage polarization. In Li parallel to Cu half-cells, the Sn@Cu mesh electrode demonstrates stable cycling for 100 cycles at a high areal capacity of 5 mAh.cm(-2), achieving a CE of 99.2%. This study introduces a simple and large-scale approach for the production of lithiophilic three-dimensional (3D) current collectors, providing more possibilities for the scalable application of Li metal batteries.