Highly-lithiophilic Ag@PDA-GO film to Suppress Dendrite Formation on Cu Substrate in Anode-free Lithium Metal Batteries

Lithium metal establishes a promising anode, but it suffers from dendrite growth. Constructing a current collector with stable artificial solid electrolyte interphase (SEI) and lithiophilic matrix is highly considered for achieving uniform lithium (Li) deposition. In this work, lithiophilic silver nanoparticles with polydopamine (Ag@PDA) were synthesized successfully and coated on the copper (Cu) current collector to use as a nucleation seed to improve the lithium nucleation. More importantly, graphene oxide (GO) was effectively coated on the top of Ag@PDA to act as artificial SEI to buffer the Li-ion distribution in anode free lithium metal batteries (AFLMBs). Thus, the synergistic effect of the modified electrodes displays a uniform Li metal deposition and dendrite free morphology during repeated cycling. Accordingly, the Cu vertical bar Ag@PDA//Li, and Cu vertical bar Ag@PDA-GO//Li cells demonstrate relatively uniform lithium nuclei, lower nucleation overpotential, and higher CE compared to the uncoated electrode. Besides, the Cu vertical bar Ag@PDA-GO//NMC full cell owns higher average Coulombic efficiency (similar to 98.6%) and higher capacity retention (similar to 55.7%) after 60 cycles within 5% fluoroethylene carbonate (FEC) in the carbonate-based electrolyte at 0.5 mA cm - 2. While, the bare copper only achieves, 94.4% and 4.3% average Coulombic efficiency and capacity retention, respectively. Therefore, a lithiophilic matrix integrated with an artificial SEI coating on the Cu substrate offers a feasible way for the inhibition of lithium dendrite and electrolyte decomposition in the anode free lithium metal batteries (AFLMBs).

Automated summary

By coating lithiophilic Ag@PDA and artificial SEI graphene oxide (GO) on the Cu current collector, a more uniform lithium deposition, lower nucleation overpotential, and higher Coulombic efficiency can be achieved. The modified electrodes show enhanced performance in inhibiting lithium dendrite growth and electrolyte decomposition in anode free lithium metal batteries.