Lithiophilic and Anticorrosive Cu Current Collector via Dual-Bonded Porous Polymer Coating for Stable Lithium-Metal Batteries

Li metal is the ultimate anode material for next -generation high-energy-density rechargeable batteries. However, the uncontrollable growth of Li dendrites and low Coulombic efficiency (CE) prevent it from practical applications in Li metal batteries (LMBs). Here, a facile and low-cost strategy is developed to decorate a Cu current collector with a self-assembled gamma-amino-propyltrimethoxysilane (gamma-APS) film. The thin polymer film with nanopores promotes the formation of cobblestone-like Li deposition and suppresses Li-dendrite formation due to its low surface energy. The protecting layer not only increases the lithiophilicity of the Cu current collector but also alleviates the ambient corrosion and galvanic corrosion in practical use. Owing to these advantages, the half cell using gamma-APS-Cu collectors exhibits a high average CE value of 99.2% for 100 cycles. The symmetric cell of gamma-APS-Cu@Li shows an improved lifespan of 1400 h with a small voltage hysteresis of 12 mV at 0.5 mA cm-2. The full cell assembled with LiFePO4 (LFP) cathodes and gamma-APS-Cu@Li anodes delivers a high capacity of 136 mAh g-1 after 600 cycles at 0.5C.

Automated summary

A facile and low-cost strategy has been developed to decorate a Cu current collector with a self-assembled polymer film, which promotes the formation of cobblestone-like Li deposition and suppresses Li-dendrite formation. The protecting layer not only increases the lithiophilicity of the Cu current collector but also alleviates the ambient corrosion and galvanic corrosion. This strategy shows promising results in improving the performance of Li metal batteries.